https://javaee.github.io/servlet-spec/: Java.net - The Source for Java Technology Collaboration (GlassFish Community) 
/*
 * Copyright (c) 1997-2018 Oracle and/or its affiliates. All rights reserved.
 * Copyright 2004 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package javax.servlet;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Enumeration;
import java.util.EnumSet;
import java.util.EventListener;
import java.util.Map;
import java.util.Set;
import javax.servlet.descriptor.JspConfigDescriptor;


Defines a set of methods that a servlet uses to communicate with its
servlet container, for example, to get the MIME type of a file,
dispatch requests, or write to a log file.

There is one context per "web application" per Java Virtual Machine.  (A
"web application" is a collection of servlets and content installed under a
specific subset of the server's URL namespace such as /catalog
and possibly installed via a .war file.)

In the case of a web
application marked "distributed" in its deployment descriptor, there will
be one context instance for each virtual machine.  In this situation, the
context cannot be used as a location to share global information (because
the information won't be truly global).  Use an external resource like
a database instead.

The ServletContext object is contained within the ServletConfig object, which the Web server provides the servlet when the servlet is initialized. 
Author:	Various
See Also:
/**
 * Defines a set of methods that a servlet uses to communicate with its
 * servlet container, for example, to get the MIME type of a file,
 * dispatch requests, or write to a log file.
 *
 * <p>There is one context per "web application" per Java Virtual Machine.  (A
 * "web application" is a collection of servlets and content installed under a
 * specific subset of the server's URL namespace such as <code>/catalog</code>
 * and possibly installed via a <code>.war</code> file.)
 *
 * <p>In the case of a web
 * application marked "distributed" in its deployment descriptor, there will
 * be one context instance for each virtual machine.  In this situation, the
 * context cannot be used as a location to share global information (because
 * the information won't be truly global).  Use an external resource like
 * a database instead.
 *
 * <p>The <code>ServletContext</code> object is contained within
 * the {@link ServletConfig} object, which the Web server provides the
 * servlet when the servlet is initialized.
 *
 * @author 	Various
 *
 * @see 	Servlet#getServletConfig
 * @see 	ServletConfig#getServletContext
 */

public interface ServletContext {

    
The name of the ServletContext attribute which stores
the private temporary directory (of type java.io.File)
provided by the servlet container for the ServletContext

/**
     * The name of the <tt>ServletContext</tt> attribute which stores
     * the private temporary directory (of type <tt>java.io.File</tt>)
     * provided by the servlet container for the <tt>ServletContext</tt>
     */
    public static final String TEMPDIR = "javax.servlet.context.tempdir";


    
The name of the ServletContext attribute whose value
(of type java.util.List<java.lang.String>) contains
the list of names of JAR files in WEB-INF/lib ordered by
their web fragment names (with possible exclusions if
<absolute-ordering> without any
<others/> is being used), or null if no
absolute or relative ordering has been specified

/**
     * The name of the <code>ServletContext</code> attribute whose value
     * (of type <code>java.util.List&lt;java.lang.String&gt;</code>) contains
     * the list of names of JAR files in <code>WEB-INF/lib</code> ordered by
     * their web fragment names (with possible exclusions if
     * <code>&lt;absolute-ordering&gt;</code> without any
     * <code>&lt;others/&gt;</code> is being used), or null if no
     * absolute or relative ordering has been specified
     */
    public static final String ORDERED_LIBS =
        "javax.servlet.context.orderedLibs";


    
Returns the context path of the web application.

The context path is the portion of the request URI that is used
to select the context of the request. The context path always comes
first in a request URI. If this context is the "root" context
rooted at the base of the Web server's URL name space, this path
will be an empty string. Otherwise, if the context is not rooted at
the root of the server's name space, the path starts with a /
character but does not end with a / character.

It is possible that a servlet container may match a context by more than one context path. In such cases the HttpServletRequest.getContextPath() will return the actual context path used by the request and it may differ from the path returned by this method. The context path returned by this method should be considered as the prime or preferred context path of the application. 
See Also:
Returns:The context path of the web application, or "" for the
root context
Since:Servlet 2.5
/**
     * Returns the context path of the web application.
     *
     * <p>The context path is the portion of the request URI that is used
     * to select the context of the request. The context path always comes
     * first in a request URI. If this context is the "root" context
     * rooted at the base of the Web server's URL name space, this path
     * will be an empty string. Otherwise, if the context is not rooted at
     * the root of the server's name space, the path starts with a /
     * character but does not end with a / character.
     *
     * <p>It is possible that a servlet container may match a context by
     * more than one context path. In such cases the
     * {@link javax.servlet.http.HttpServletRequest#getContextPath()}
     * will return the actual context path used by the request and it may
     * differ from the path returned by this method.
     * The context path returned by this method should be considered as the
     * prime or preferred context path of the application.
     *
     * @return The context path of the web application, or "" for the
     * root context
     *
     * @see javax.servlet.http.HttpServletRequest#getContextPath()
     *
     * @since Servlet 2.5
     */
    public String getContextPath();


    
Returns a ServletContext object that
corresponds to a specified URL on the server.

This method allows servlets to gain access to the context for various parts of the server, and as needed obtain RequestDispatcher objects from the context. The given path must be begin with /, is interpreted relative
to the server's document root and is matched against the context
roots of other web applications hosted on this container.

In a security conscious environment, the servlet container may
return null for a given URL.

Params:
  • uripath – 	a String specifying the context path of
		another web application in the container.
See Also:
Returns:		the ServletContext object that
		corresponds to the named URL, or null if either
none exists or the container wishes to restrict
			this access.
/**
     * Returns a <code>ServletContext</code> object that
     * corresponds to a specified URL on the server.
     *
     * <p>This method allows servlets to gain
     * access to the context for various parts of the server, and as
     * needed obtain {@link RequestDispatcher} objects from the context.
     * The given path must be begin with <tt>/</tt>, is interpreted relative
     * to the server's document root and is matched against the context
     * roots of other web applications hosted on this container.
     *
     * <p>In a security conscious environment, the servlet container may
     * return <code>null</code> for a given URL.
     *
     * @param uripath 	a <code>String</code> specifying the context path of
     *			another web application in the container.
     * @return		the <code>ServletContext</code> object that
     *			corresponds to the named URL, or null if either
			none exists or the container wishes to restrict
     * 			this access.
     *
     * @see 		RequestDispatcher
     */
    public ServletContext getContext(String uripath);


    
Returns the major version of the Servlet API that this
servlet container supports. All implementations that comply
with Version 4.0 must have this method return the integer 4.

Returns:4
/**
     * Returns the major version of the Servlet API that this
     * servlet container supports. All implementations that comply
     * with Version 4.0 must have this method return the integer 4.
     *
     * @return 4
     */
    public int getMajorVersion();


    
Returns the minor version of the Servlet API that this
servlet container supports. All implementations that comply
with Version 4.0 must have this method return the integer 0.

Returns:0
/**
     * Returns the minor version of the Servlet API that this
     * servlet container supports. All implementations that comply
     * with Version 4.0 must have this method return the integer 0.
     *
     * @return 0
     */
    public int getMinorVersion();


    
Gets the major version of the Servlet specification that the
application represented by this ServletContext is based on.

The value returned may be different from getMajorVersion, which returns the major version of the Servlet specification supported by the Servlet container. 
Throws:
Returns:the major version of the Servlet specification that the
application represented by this ServletContext is based on
Since:Servlet 3.0
/**
     * Gets the major version of the Servlet specification that the
     * application represented by this ServletContext is based on.
     *
     * <p>The value returned may be different from {@link #getMajorVersion},
     * which returns the major version of the Servlet specification
     * supported by the Servlet container.
     *
     * @return the major version of the Servlet specification that the
     * application represented by this ServletContext is based on
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public int getEffectiveMajorVersion();


    
Gets the minor version of the Servlet specification that the
application represented by this ServletContext is based on.

The value returned may be different from getMinorVersion, which returns the minor version of the Servlet specification supported by the Servlet container. 
Throws:
Returns:the minor version of the Servlet specification that the
application represented by this ServletContext is based on
Since:Servlet 3.0
/**
     * Gets the minor version of the Servlet specification that the
     * application represented by this ServletContext is based on.
     *
     * <p>The value returned may be different from {@link #getMinorVersion},
     * which returns the minor version of the Servlet specification
     * supported by the Servlet container.
     *
     * @return the minor version of the Servlet specification that the
     * application represented by this ServletContext is based on
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public int getEffectiveMinorVersion();


    
Returns the MIME type of the specified file, or null if
the MIME type is not known. The MIME type is determined
by the configuration of the servlet container, and may be specified
in a web application deployment descriptor. Common MIME
types include text/html and image/gif.

Params:
  • file – a String specifying the name of a file
Returns:a String specifying the file's MIME type
/**
     * Returns the MIME type of the specified file, or <code>null</code> if
     * the MIME type is not known. The MIME type is determined
     * by the configuration of the servlet container, and may be specified
     * in a web application deployment descriptor. Common MIME
     * types include <code>text/html</code> and <code>image/gif</code>.
     *
     * @param file a <code>String</code> specifying the name of a file
     *
     * @return a <code>String</code> specifying the file's MIME type
     */
    public String getMimeType(String file);


    
Returns a directory-like listing of all the paths to resources
within the web application whose longest sub-path matches the
supplied path argument.

Paths indicating subdirectory paths end with a /.

The returned paths are all relative to the root of the web
application, or relative to the /META-INF/resources
directory of a JAR file inside the web application's
/WEB-INF/lib directory, and have a leading /.

The returned set is not backed by the ServletContext object, so changes in the returned set are not reflected in the ServletContext object, and vice-versa.


For example, for a web application containing:


  /welcome.html
  /catalog/index.html
  /catalog/products.html
  /catalog/offers/books.html
  /catalog/offers/music.html
  /customer/login.jsp
  /WEB-INF/web.xml
  /WEB-INF/classes/com.acme.OrderServlet.class
  /WEB-INF/lib/catalog.jar!/META-INF/resources/catalog/moreOffers/books.html


getResourcePaths("/") would return
{"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"},
and getResourcePaths("/catalog/") would return
{"/catalog/index.html", "/catalog/products.html",
"/catalog/offers/", "/catalog/moreOffers/"}.

Params:
  • path – the partial path used to match the resources,
which must start with a /
Returns:a Set containing the directory listing, or null if there
are no resources in the web application whose path
begins with the supplied path.
Since:Servlet 2.3
/**
     * Returns a directory-like listing of all the paths to resources
     * within the web application whose longest sub-path matches the
     * supplied path argument.
     *
     * <p>Paths indicating subdirectory paths end with a <tt>/</tt>.
     *
     * <p>The returned paths are all relative to the root of the web
     * application, or relative to the <tt>/META-INF/resources</tt>
     * directory of a JAR file inside the web application's
     * <tt>/WEB-INF/lib</tt> directory, and have a leading <tt>/</tt>.
     *
     * <p>The returned set is not backed by the {@code ServletContext} object,
     * so changes in the returned set are not reflected in the
     * {@code ServletContext} object, and vice-versa.</p>
     *
     * <p>For example, for a web application containing:
     *
     * <pre>{@code
     *   /welcome.html
     *   /catalog/index.html
     *   /catalog/products.html
     *   /catalog/offers/books.html
     *   /catalog/offers/music.html
     *   /customer/login.jsp
     *   /WEB-INF/web.xml
     *   /WEB-INF/classes/com.acme.OrderServlet.class
     *   /WEB-INF/lib/catalog.jar!/META-INF/resources/catalog/moreOffers/books.html
     * }</pre>
     *
     * <tt>getResourcePaths("/")</tt> would return
     * <tt>{"/welcome.html", "/catalog/", "/customer/", "/WEB-INF/"}</tt>,
     * and <tt>getResourcePaths("/catalog/")</tt> would return
     * <tt>{"/catalog/index.html", "/catalog/products.html",
     * "/catalog/offers/", "/catalog/moreOffers/"}</tt>.
     *
     * @param path the partial path used to match the resources,
     * which must start with a <tt>/</tt>
     * @return a Set containing the directory listing, or null if there
     * are no resources in the web application whose path
     * begins with the supplied path.
     *
     * @since Servlet 2.3
     */
    public Set<String> getResourcePaths(String path);


    
Returns a URL to the resource that is mapped to the given path.

The path must begin with a / and is interpreted
as relative to the current context root,
or relative to the /META-INF/resources directory
of a JAR file inside the web application's /WEB-INF/lib
directory.
This method will first search the document root of the
web application for the requested resource, before searching
any of the JAR files inside /WEB-INF/lib.
The order in which the JAR files inside /WEB-INF/lib
are searched is undefined.

This method allows the servlet container to make a resource
available to servlets from any source. Resources
can be located on a local or remote
file system, in a database, or in a .war file.

The servlet container must implement the URL handlers
and URLConnection objects that are necessary
to access the resource.

This method returns null
if no resource is mapped to the pathname.

Some containers may allow writing to the URL returned by
this method using the methods of the URL class.

The resource content is returned directly, so be aware that
requesting a .jsp page returns the JSP source code.
Use a RequestDispatcher instead to include results of
an execution.

This method has a different purpose than
java.lang.Class.getResource,
which looks up resources based on a class loader. This
method does not use class loaders.

Params:
  • path – a String specifying
the path to the resource
Throws:
Returns:the resource located at the named path,
or null if there is no resource at that path
/**
     * Returns a URL to the resource that is mapped to the given path.
     *
     * <p>The path must begin with a <tt>/</tt> and is interpreted
     * as relative to the current context root,
     * or relative to the <tt>/META-INF/resources</tt> directory
     * of a JAR file inside the web application's <tt>/WEB-INF/lib</tt>
     * directory.
     * This method will first search the document root of the
     * web application for the requested resource, before searching
     * any of the JAR files inside <tt>/WEB-INF/lib</tt>.
     * The order in which the JAR files inside <tt>/WEB-INF/lib</tt>
     * are searched is undefined.
     *
     * <p>This method allows the servlet container to make a resource
     * available to servlets from any source. Resources
     * can be located on a local or remote
     * file system, in a database, or in a <code>.war</code> file.
     *
     * <p>The servlet container must implement the URL handlers
     * and <code>URLConnection</code> objects that are necessary
     * to access the resource.
     *
     * <p>This method returns <code>null</code>
     * if no resource is mapped to the pathname.
     *
     * <p>Some containers may allow writing to the URL returned by
     * this method using the methods of the URL class.
     *
     * <p>The resource content is returned directly, so be aware that
     * requesting a <code>.jsp</code> page returns the JSP source code.
     * Use a <code>RequestDispatcher</code> instead to include results of
     * an execution.
     *
     * <p>This method has a different purpose than
     * <code>java.lang.Class.getResource</code>,
     * which looks up resources based on a class loader. This
     * method does not use class loaders.
     *
     * @param path a <code>String</code> specifying
     * the path to the resource
     *
     * @return the resource located at the named path,
     * or <code>null</code> if there is no resource at that path
     *
     * @exception MalformedURLException if the pathname is not given in
     * the correct form
     */
    public URL getResource(String path) throws MalformedURLException;


    
Returns the resource located at the named path as
an InputStream object.

The data in the InputStream can be
of any type or length. The path must be specified according
to the rules given in getResource.
This method returns null if no resource exists at
the specified path.

Meta-information such as content length and content type
that is available via getResource
method is lost when using this method.

The servlet container must implement the URL handlers
and URLConnection objects necessary to access
the resource.

This method is different from
java.lang.Class.getResourceAsStream,
which uses a class loader. This method allows servlet containers
to make a resource available
to a servlet from any location, without using a class loader.

Params:
  • path – 	a String specifying the path
		to the resource
Returns:		the InputStream returned to the
		servlet, or null if no resource
		exists at the specified path
/**
     * Returns the resource located at the named path as
     * an <code>InputStream</code> object.
     *
     * <p>The data in the <code>InputStream</code> can be
     * of any type or length. The path must be specified according
     * to the rules given in <code>getResource</code>.
     * This method returns <code>null</code> if no resource exists at
     * the specified path.
     *
     * <p>Meta-information such as content length and content type
     * that is available via <code>getResource</code>
     * method is lost when using this method.
     *
     * <p>The servlet container must implement the URL handlers
     * and <code>URLConnection</code> objects necessary to access
     * the resource.
     *
     * <p>This method is different from
     * <code>java.lang.Class.getResourceAsStream</code>,
     * which uses a class loader. This method allows servlet containers
     * to make a resource available
     * to a servlet from any location, without using a class loader.
     *
     *
     * @param path 	a <code>String</code> specifying the path
     *			to the resource
     *
     * @return 		the <code>InputStream</code> returned to the
     *			servlet, or <code>null</code> if no resource
     *			exists at the specified path
     */
    public InputStream getResourceAsStream(String path);


    
Returns a RequestDispatcher object that acts as a wrapper for the resource located at the given path. A RequestDispatcher object can be used to forward
a request to the resource or to include the resource in a response.
The resource can be dynamic or static.

The pathname must begin with a / and is interpreted as
relative to the current context root.  Use getContext
to obtain a RequestDispatcher for resources in foreign
contexts.

This method returns null if the
ServletContext cannot return a
RequestDispatcher.

Params:
  • path – 	a String specifying the pathname
		to the resource
See Also:
Returns:		a RequestDispatcher object
		that acts as a wrapper for the resource
		at the specified path, or null if
		the ServletContext cannot return
		a RequestDispatcher
/**
     *
     * Returns a {@link RequestDispatcher} object that acts
     * as a wrapper for the resource located at the given path.
     * A <code>RequestDispatcher</code> object can be used to forward
     * a request to the resource or to include the resource in a response.
     * The resource can be dynamic or static.
     *
     * <p>The pathname must begin with a <tt>/</tt> and is interpreted as
     * relative to the current context root.  Use <code>getContext</code>
     * to obtain a <code>RequestDispatcher</code> for resources in foreign
     * contexts.
     *
     * <p>This method returns <code>null</code> if the
     * <code>ServletContext</code> cannot return a
     * <code>RequestDispatcher</code>.
     *
     * @param path 	a <code>String</code> specifying the pathname
     *			to the resource
     *
     * @return 		a <code>RequestDispatcher</code> object
     *			that acts as a wrapper for the resource
     *			at the specified path, or <code>null</code> if
     *			the <code>ServletContext</code> cannot return
     *			a <code>RequestDispatcher</code>
     *
     * @see 		RequestDispatcher
     * @see 		ServletContext#getContext
     */
    public RequestDispatcher getRequestDispatcher(String path);


    
Returns a RequestDispatcher object that acts as a wrapper for the named servlet. 
Servlets (and JSP pages also) may be given names via server administration or via a web application deployment descriptor. A servlet instance can determine its name using ServletConfig.getServletName. 
This method returns null if the
ServletContext
cannot return a RequestDispatcher for any reason.

Params:
  • name – 	a String specifying the name
		of a servlet to wrap
See Also:
Returns:		a RequestDispatcher object
		that acts as a wrapper for the named servlet,
		or null if the ServletContext
		cannot return a RequestDispatcher
/**
     * Returns a {@link RequestDispatcher} object that acts
     * as a wrapper for the named servlet.
     *
     * <p>Servlets (and JSP pages also) may be given names via server
     * administration or via a web application deployment descriptor.
     * A servlet instance can determine its name using
     * {@link ServletConfig#getServletName}.
     *
     * <p>This method returns <code>null</code> if the
     * <code>ServletContext</code>
     * cannot return a <code>RequestDispatcher</code> for any reason.
     *
     * @param name 	a <code>String</code> specifying the name
     *			of a servlet to wrap
     *
     * @return 		a <code>RequestDispatcher</code> object
     *			that acts as a wrapper for the named servlet,
     *			or <code>null</code> if the <code>ServletContext</code>
     *			cannot return a <code>RequestDispatcher</code>
     *
     * @see 		RequestDispatcher
     * @see 		ServletContext#getContext
     * @see 		ServletConfig#getServletName
     */
    public RequestDispatcher getNamedDispatcher(String name);


    
Params:
  • name – the servlet name
Throws:
  • ServletException – if an exception has occurred that interfaces
                         with servlet's normal operation
Deprecated:	As of Java Servlet API 2.1, with no direct replacement.

This method was originally defined to retrieve a servlet
from a ServletContext. In this version, this method
always returns null and remains only to preserve
binary compatibility. This method will be permanently removed
in a future version of the Java Servlet API.

In lieu of this method, servlets can share information using the
ServletContext class and can perform shared business logic
by invoking methods on common non-servlet classes.
Returns:the javax.servlet.Servlet Servlet with the given name
/**
     * @deprecated	As of Java Servlet API 2.1, with no direct replacement.
     *
     * <p>This method was originally defined to retrieve a servlet
     * from a <code>ServletContext</code>. In this version, this method
     * always returns <code>null</code> and remains only to preserve
     * binary compatibility. This method will be permanently removed
     * in a future version of the Java Servlet API.
     *
     * <p>In lieu of this method, servlets can share information using the
     * <code>ServletContext</code> class and can perform shared business logic
     * by invoking methods on common non-servlet classes.
     *
     * @param name the servlet name
     * @return the {@code javax.servlet.Servlet Servlet} with the given name
     * @throws ServletException if an exception has occurred that interfaces
     *                          with servlet's normal operation
     */
    @Deprecated
    public Servlet getServlet(String name) throws ServletException;


    
Deprecated:	As of Java Servlet API 2.0, with no replacement.

This method was originally defined to return an
Enumeration of all the servlets known to this servlet
context.
In this version, this method always returns an empty enumeration and
remains only to preserve binary compatibility. This method
will be permanently removed in a future version of the Java
Servlet API.
Returns:an Enumeration of javax.servlet.Servlet Servlet
/**
     * @deprecated	As of Java Servlet API 2.0, with no replacement.
     *
     * <p>This method was originally defined to return an
     * <code>Enumeration</code> of all the servlets known to this servlet
     * context.
     * In this version, this method always returns an empty enumeration and
     * remains only to preserve binary compatibility. This method
     * will be permanently removed in a future version of the Java
     * Servlet API.
     *
     * @return an <code>Enumeration</code> of {@code javax.servlet.Servlet Servlet}
     */
    @Deprecated
    public Enumeration<Servlet> getServlets();


    
Deprecated:	As of Java Servlet API 2.1, with no replacement.

This method was originally defined to return an
Enumeration
of all the servlet names known to this context. In this version,
this method always returns an empty Enumeration and
remains only to preserve binary compatibility. This method will
be permanently removed in a future version of the Java Servlet API.
Returns:an Enumeration of javax.servlet.Servlet Servlet names
/**
     * @deprecated	As of Java Servlet API 2.1, with no replacement.
     *
     * <p>This method was originally defined to return an
     * <code>Enumeration</code>
     * of all the servlet names known to this context. In this version,
     * this method always returns an empty <code>Enumeration</code> and
     * remains only to preserve binary compatibility. This method will
     * be permanently removed in a future version of the Java Servlet API.
     *
     * @return an <code>Enumeration</code> of {@code javax.servlet.Servlet Servlet} names
     */
    @Deprecated
    public Enumeration<String> getServletNames();


    
Writes the specified message to a servlet log file, usually
an event log. The name and type of the servlet log file is
specific to the servlet container.

Params:
  • msg – 	a String specifying the
		message to be written to the log file
/**
     *
     * Writes the specified message to a servlet log file, usually
     * an event log. The name and type of the servlet log file is
     * specific to the servlet container.
     *
     * @param msg 	a <code>String</code> specifying the
     *			message to be written to the log file
     */
    public void log(String msg);


    
Params:
  • exception – the Exception error
  • msg – a String that describes the exception
Deprecated: As of Java Servlet API 2.1, use log(String message, Throwable throwable) instead. 
This method was originally defined to write an
exception's stack trace and an explanatory error message
to the servlet log file.
/**
     * @deprecated	As of Java Servlet API 2.1, use
     * 			{@link #log(String message, Throwable throwable)}
     *			instead.
     *
     * <p>This method was originally defined to write an
     * exception's stack trace and an explanatory error message
     * to the servlet log file.
     *
     * @param exception the <code>Exception</code> error
     * @param msg a <code>String</code> that describes the exception
     */
    @Deprecated
    public void log(Exception exception, String msg);


    
Writes an explanatory message and a stack trace
for a given Throwable exception
to the servlet log file. The name and type of the servlet log
file is specific to the servlet container, usually an event log.

Params:
  • message – 		a String that
			describes the error or exception
  • throwable – 	the Throwable error
			or exception
/**
     * Writes an explanatory message and a stack trace
     * for a given <code>Throwable</code> exception
     * to the servlet log file. The name and type of the servlet log
     * file is specific to the servlet container, usually an event log.
     *
     * @param message 		a <code>String</code> that
     *				describes the error or exception
     *
     * @param throwable 	the <code>Throwable</code> error
     *				or exception
     */
    public void log(String message, Throwable throwable);


    
Gets the real path corresponding to the given
virtual path.

For example, if path is equal to /index.html,
this method will return the absolute file path on the server's
filesystem to which a request of the form
http://<host>:<port>/<contextPath>/index.html
would be mapped, where <contextPath> corresponds to the
context path of this ServletContext.

The real path returned will be in a form
appropriate to the computer and operating system on
which the servlet container is running, including the
proper path separators.

Resources inside the /META-INF/resources
directories of JAR files bundled in the application's
/WEB-INF/lib directory must be considered only if the
container has unpacked them from their containing JAR file, in
which case the path to the unpacked location must be returned.

This method returns null if the servlet container
is unable to translate the given virtual path to a
real path.

Params:
  • path – the virtual path to be translated to a
real path
Returns:the real path, or null if the
translation cannot be performed
/**
     * Gets the <i>real</i> path corresponding to the given
     * <i>virtual</i> path.
     *
     * <p>For example, if <tt>path</tt> is equal to <tt>/index.html</tt>,
     * this method will return the absolute file path on the server's
     * filesystem to which a request of the form
     * <tt>http://&lt;host&gt;:&lt;port&gt;/&lt;contextPath&gt;/index.html</tt>
     * would be mapped, where <tt>&lt;contextPath&gt;</tt> corresponds to the
     * context path of this ServletContext.
     *
     * <p>The real path returned will be in a form
     * appropriate to the computer and operating system on
     * which the servlet container is running, including the
     * proper path separators.
     *
     * <p>Resources inside the <tt>/META-INF/resources</tt>
     * directories of JAR files bundled in the application's
     * <tt>/WEB-INF/lib</tt> directory must be considered only if the
     * container has unpacked them from their containing JAR file, in
     * which case the path to the unpacked location must be returned.
     *
     * <p>This method returns <code>null</code> if the servlet container
     * is unable to translate the given <i>virtual</i> path to a
     * <i>real</i> path.
     *
     * @param path the <i>virtual</i> path to be translated to a
     * <i>real</i> path
     *
     * @return the <i>real</i> path, or <tt>null</tt> if the
     * translation cannot be performed
     */
    public String getRealPath(String path);


    
Returns the name and version of the servlet container on which
the servlet is running.

The form of the returned string is
servername/versionnumber.
For example, the JavaServer Web Development Kit may return the string
JavaServer Web Dev Kit/1.0.

The servlet container may return other optional information
after the primary string in parentheses, for example,
JavaServer Web Dev Kit/1.0 (JDK 1.1.6; Windows NT 4.0 x86).

Returns:		a String containing at least the
		servlet container name and version number
/**
     * Returns the name and version of the servlet container on which
     * the servlet is running.
     *
     * <p>The form of the returned string is
     * <i>servername</i>/<i>versionnumber</i>.
     * For example, the JavaServer Web Development Kit may return the string
     * <code>JavaServer Web Dev Kit/1.0</code>.
     *
     * <p>The servlet container may return other optional information
     * after the primary string in parentheses, for example,
     * <code>JavaServer Web Dev Kit/1.0 (JDK 1.1.6; Windows NT 4.0 x86)</code>.
     *
     *
     * @return 		a <code>String</code> containing at least the
     *			servlet container name and version number
     */
    public String getServerInfo();


    
Returns a String containing the value of the named
context-wide initialization parameter, or null if
the parameter does not exist.

This method can make available configuration information useful
to an entire web application.  For example, it can provide a
webmaster's email address or the name of a system that holds
critical data.

Params:
  • name – 	a String containing the name of the
                 parameter whose value is requested
Throws:
See Also:
Returns:a String containing the value of the
context's initialization parameter, or null if the
context's initialization parameter does not exist.
/**
     * Returns a <code>String</code> containing the value of the named
     * context-wide initialization parameter, or <code>null</code> if
     * the parameter does not exist.
     *
     * <p>This method can make available configuration information useful
     * to an entire web application.  For example, it can provide a
     * webmaster's email address or the name of a system that holds
     * critical data.
     *
     * @param	name	a <code>String</code> containing the name of the
     *                  parameter whose value is requested
     *
     * @return a <code>String</code> containing the value of the
     * context's initialization parameter, or <code>null</code> if the
     * context's initialization parameter does not exist.
     *
     * @throws NullPointerException if the argument {@code name} is
     * {@code null}
     *
     * @see ServletConfig#getInitParameter
     */
    public String getInitParameter(String name);


    
Returns the names of the context's initialization parameters as an
Enumeration of String objects, or an
empty Enumeration if the context has no initialization
parameters.

See Also:
Returns:		an Enumeration of String
                 objects containing the names of the context's
                 initialization parameters
/**
     * Returns the names of the context's initialization parameters as an
     * <code>Enumeration</code> of <code>String</code> objects, or an
     * empty <code>Enumeration</code> if the context has no initialization
     * parameters.
     *
     * @return 		an <code>Enumeration</code> of <code>String</code>
     *                  objects containing the names of the context's
     *                  initialization parameters
     *
     * @see ServletConfig#getInitParameter
     */
    public Enumeration<String> getInitParameterNames();


    
Sets the context initialization parameter with the given name and
value on this ServletContext.

Params:
  • name – the name of the context initialization parameter to set
  • value – the value of the context initialization parameter to set
Throws:
Returns:true if the context initialization parameter with the given
name and value was set successfully on this ServletContext, and false
if it was not set because this ServletContext already contains a
context initialization parameter with a matching name
Since:Servlet 3.0
/**
     * Sets the context initialization parameter with the given name and
     * value on this ServletContext.
     *
     * @param name the name of the context initialization parameter to set
     * @param value the value of the context initialization parameter to set
     *
     * @return true if the context initialization parameter with the given
     * name and value was set successfully on this ServletContext, and false
     * if it was not set because this ServletContext already contains a
     * context initialization parameter with a matching name
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws NullPointerException if the name parameter is {@code null}
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public boolean setInitParameter(String name, String value);


    
Returns the servlet container attribute with the given name, or
null if there is no attribute by that name.

An attribute allows a servlet container to give the
servlet additional information not
already provided by this interface. See your
server documentation for information about its attributes.
A list of supported attributes can be retrieved using
getAttributeNames.

The attribute is returned as a java.lang.Object
or some subclass.

Attribute names should follow the same convention as package
names. The Java Servlet API specification reserves names
matching java.*, javax.*,
and sun.*.

Params:
  • name – 	a String specifying the name
		of the attribute
Throws:
See Also:
Returns:an Object containing the value of the
		attribute, or null if no attribute
		exists matching the given name.
/**
     * Returns the servlet container attribute with the given name, or
     * <code>null</code> if there is no attribute by that name.
     *
     * <p>An attribute allows a servlet container to give the
     * servlet additional information not
     * already provided by this interface. See your
     * server documentation for information about its attributes.
     * A list of supported attributes can be retrieved using
     * <code>getAttributeNames</code>.
     *
     * <p>The attribute is returned as a <code>java.lang.Object</code>
     * or some subclass.
     *
     * <p>Attribute names should follow the same convention as package
     * names. The Java Servlet API specification reserves names
     * matching <code>java.*</code>, <code>javax.*</code>,
     * and <code>sun.*</code>.
     *
     * @param name 	a <code>String</code> specifying the name
     *			of the attribute
     *
     * @return an <code>Object</code> containing the value of the
     *			attribute, or <code>null</code> if no attribute
     *			exists matching the given name.
     *
     * @see 		ServletContext#getAttributeNames
     *
     * @throws NullPointerException if the argument {@code name} is
     * {@code null}
     *
     */
    public Object getAttribute(String name);


    
Returns an Enumeration containing the
attribute names available within this ServletContext.

Use the getAttribute method with an attribute name to get the value of an attribute. 
See Also:
Returns:		an Enumeration of attribute
		names
/**
     * Returns an <code>Enumeration</code> containing the
     * attribute names available within this ServletContext.
     *
     * <p>Use the {@link #getAttribute} method with an attribute name
     * to get the value of an attribute.
     *
     * @return 		an <code>Enumeration</code> of attribute
     *			names
     *
     * @see		#getAttribute
     */
    public Enumeration<String> getAttributeNames();


    
Binds an object to a given attribute name in this ServletContext. If
the name specified is already used for an attribute, this
method will replace the attribute with the new to the new attribute.

If listeners are configured on the ServletContext the
container notifies them accordingly.


If a null value is passed, the effect is the same as calling
removeAttribute().

Attribute names should follow the same convention as package
names. The Java Servlet API specification reserves names
matching java.*, javax.*, and
sun.*.

Params:
  • name – 	a String specifying the name
		of the attribute
  • object – 	an Object representing the
		attribute to be bound
Throws:
/**
     * Binds an object to a given attribute name in this ServletContext. If
     * the name specified is already used for an attribute, this
     * method will replace the attribute with the new to the new attribute.
     * <p>If listeners are configured on the <code>ServletContext</code> the
     * container notifies them accordingly.
     * <p>
     * If a null value is passed, the effect is the same as calling
     * <code>removeAttribute()</code>.
     *
     * <p>Attribute names should follow the same convention as package
     * names. The Java Servlet API specification reserves names
     * matching <code>java.*</code>, <code>javax.*</code>, and
     * <code>sun.*</code>.
     *
     * @param name 	a <code>String</code> specifying the name
     *			of the attribute
     *
     * @param object 	an <code>Object</code> representing the
     *			attribute to be bound
     *
     * @throws NullPointerException if the name parameter is {@code null}
     *
     */
    public void setAttribute(String name, Object object);


    
Removes the attribute with the given name from this ServletContext. After removal, subsequent calls to getAttribute to retrieve the attribute's value will return null.

If listeners are configured on the ServletContext the
container notifies them accordingly.

Params:
  • name – 	a String specifying the name
			of the attribute to be removed
/**
     * Removes the attribute with the given name from
     * this ServletContext. After removal, subsequent calls to
     * {@link #getAttribute} to retrieve the attribute's value
     * will return <code>null</code>.
     *
     * <p>If listeners are configured on the <code>ServletContext</code> the
     * container notifies them accordingly.
     *
     * @param name	a <code>String</code> specifying the name
     * 			of the attribute to be removed
     */
    public void removeAttribute(String name);


    
Returns the name of this web application corresponding to this
ServletContext as specified in the deployment descriptor for this
web application by the display-name element.

Returns:The name of the web application or null if no name has been
declared in the deployment descriptor.
Since:Servlet 2.3
/**
     * Returns the name of this web application corresponding to this
     * ServletContext as specified in the deployment descriptor for this
     * web application by the display-name element.
     *
     * @return The name of the web application or null if no name has been
     * declared in the deployment descriptor.
     *
     * @since Servlet 2.3
     */
    public String getServletContextName();


    
Adds the servlet with the given name and class name to this servlet
context.

The registered servlet may be further configured via the returned ServletRegistration object. 
The specified className will be loaded using the
classloader associated with the application represented by this
ServletContext.

If this ServletContext already contains a preliminary
ServletRegistration for a servlet with the given servletName,
it will be completed (by assigning the given className to it)
and returned.

This method introspects the class with the given className for the ServletSecurity, MultipartConfig, javax.annotation.security.RunAs, and
javax.annotation.security.DeclareRoles annotations.
In addition, this method supports resource injection if the
class with the given className represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • servletName – the name of the servlet
  • className – the fully qualified class name of the servlet
Throws:
Returns:a ServletRegistration object that may be used to further
configure the registered servlet, or null if this
ServletContext already contains a complete ServletRegistration for
a servlet with the given servletName
Since:Servlet 3.0
/**
     * Adds the servlet with the given name and class name to this servlet
     * context.
     *
     * <p>The registered servlet may be further configured via the returned
     * {@link ServletRegistration} object.
     *
     * <p>The specified <tt>className</tt> will be loaded using the
     * classloader associated with the application represented by this
     * ServletContext.
     *
     * <p>If this ServletContext already contains a preliminary
     * ServletRegistration for a servlet with the given <tt>servletName</tt>,
     * it will be completed (by assigning the given <tt>className</tt> to it)
     * and returned.
     *
     * <p>This method introspects the class with the given <tt>className</tt>
     * for the {@link javax.servlet.annotation.ServletSecurity},
     * {@link javax.servlet.annotation.MultipartConfig},
     * <tt>javax.annotation.security.RunAs</tt>, and
     * <tt>javax.annotation.security.DeclareRoles</tt> annotations.
     * In addition, this method supports resource injection if the
     * class with the given <tt>className</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param servletName the name of the servlet
     * @param className the fully qualified class name of the servlet
     *
     * @return a ServletRegistration object that may be used to further
     * configure the registered servlet, or <tt>null</tt> if this
     * ServletContext already contains a complete ServletRegistration for
     * a servlet with the given <tt>servletName</tt>
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws IllegalArgumentException if <code>servletName</code> is null
     * or an empty String
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public ServletRegistration.Dynamic addServlet(
        String servletName, String className);


    
Registers the given servlet instance with this ServletContext
under the given servletName.

The registered servlet may be further configured via the returned ServletRegistration object. 
If this ServletContext already contains a preliminary
ServletRegistration for a servlet with the given servletName,
it will be completed (by assigning the class name of the given servlet
instance to it) and returned.

Params:
  • servletName – the name of the servlet
  • servlet – the servlet instance to register
Throws:
Returns:a ServletRegistration object that may be used to further
configure the given servlet, or null if this
ServletContext already contains a complete ServletRegistration for a
servlet with the given servletName or if the same servlet
instance has already been registered with this or another
ServletContext in the same container
Since:Servlet 3.0
/**
     * Registers the given servlet instance with this ServletContext
     * under the given <tt>servletName</tt>.
     *
     * <p>The registered servlet may be further configured via the returned
     * {@link ServletRegistration} object.
     *
     * <p>If this ServletContext already contains a preliminary
     * ServletRegistration for a servlet with the given <tt>servletName</tt>,
     * it will be completed (by assigning the class name of the given servlet
     * instance to it) and returned.
     *
     * @param servletName the name of the servlet
     * @param servlet the servlet instance to register
     *
     * @return a ServletRegistration object that may be used to further
     * configure the given servlet, or <tt>null</tt> if this
     * ServletContext already contains a complete ServletRegistration for a
     * servlet with the given <tt>servletName</tt> or if the same servlet
     * instance has already been registered with this or another
     * ServletContext in the same container
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @throws IllegalArgumentException if the given servlet instance
     * implements {@link SingleThreadModel}, or <code>servletName</code> is null
     * or an empty String
     *
     * @since Servlet 3.0
     */
    public ServletRegistration.Dynamic addServlet(
        String servletName, Servlet servlet);


    
Adds the servlet with the given name and class type to this servlet
context.

The registered servlet may be further configured via the returned ServletRegistration object. 
If this ServletContext already contains a preliminary
ServletRegistration for a servlet with the given servletName,
it will be completed (by assigning the name of the given
servletClass to it) and returned.

This method introspects the given servletClass for the ServletSecurity, MultipartConfig, javax.annotation.security.RunAs, and
javax.annotation.security.DeclareRoles annotations.
In addition, this method supports resource injection if the
given servletClass represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • servletName – the name of the servlet
  • servletClass – the class object from which the servlet will be
instantiated
Throws:
Returns:a ServletRegistration object that may be used to further
configure the registered servlet, or null if this
ServletContext already contains a complete ServletRegistration for
the given servletName
Since:Servlet 3.0
/**
     * Adds the servlet with the given name and class type to this servlet
     * context.
     *
     * <p>The registered servlet may be further configured via the returned
     * {@link ServletRegistration} object.
     *
     * <p>If this ServletContext already contains a preliminary
     * ServletRegistration for a servlet with the given <tt>servletName</tt>,
     * it will be completed (by assigning the name of the given
     * <tt>servletClass</tt> to it) and returned.
     *
     * <p>This method introspects the given <tt>servletClass</tt> for
     * the {@link javax.servlet.annotation.ServletSecurity},
     * {@link javax.servlet.annotation.MultipartConfig},
     * <tt>javax.annotation.security.RunAs</tt>, and
     * <tt>javax.annotation.security.DeclareRoles</tt> annotations.
     * In addition, this method supports resource injection if the
     * given <tt>servletClass</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param servletName the name of the servlet
     * @param servletClass the class object from which the servlet will be
     * instantiated
     *
     * @return a ServletRegistration object that may be used to further
     * configure the registered servlet, or <tt>null</tt> if this
     * ServletContext already contains a complete ServletRegistration for
     * the given <tt>servletName</tt>
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws IllegalArgumentException if <code>servletName</code> is null
     * or an empty String
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public ServletRegistration.Dynamic addServlet(String servletName,
        Class <? extends Servlet> servletClass);


    
Adds the servlet with the given jsp file to this servlet context.

The registered servlet may be further configured via the returned ServletRegistration object. 
If this ServletContext already contains a preliminary
ServletRegistration for a servlet with the given servletName,
it will be completed (by assigning the given jspFile to it)
and returned.

Params:
  • servletName – the name of the servlet
  • jspFile – the full path to a JSP file within the web application
               beginning with a `/'.
Throws:
Returns:a ServletRegistration object that may be used to further
configure the registered servlet, or null if this
ServletContext already contains a complete ServletRegistration for
a servlet with the given servletName
Since:Servlet 4.0
/**
     * Adds the servlet with the given jsp file to this servlet context.
     *
     * <p>The registered servlet may be further configured via the returned
     * {@link ServletRegistration} object.
     *
     * <p>If this ServletContext already contains a preliminary
     * ServletRegistration for a servlet with the given <tt>servletName</tt>,
     * it will be completed (by assigning the given <tt>jspFile</tt> to it)
     * and returned.
     *
     * @param servletName the name of the servlet
     * @param jspFile the full path to a JSP file within the web application
     *                beginning with a `/'.
     *
     * @return a ServletRegistration object that may be used to further
     * configure the registered servlet, or <tt>null</tt> if this
     * ServletContext already contains a complete ServletRegistration for
     * a servlet with the given <tt>servletName</tt>
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws IllegalArgumentException if <code>servletName</code> is null
     * or an empty String
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public ServletRegistration.Dynamic addJspFile(
        String servletName, String jspFile);


    
Instantiates the given Servlet class.

The returned Servlet instance may be further customized before it is registered with this ServletContext via a call to addServlet(String, Servlet). 
The given Servlet class must define a zero argument constructor,
which is used to instantiate it.

This method introspects the given clazz for the following annotations: ServletSecurity, MultipartConfig, javax.annotation.security.RunAs, and
javax.annotation.security.DeclareRoles.
In addition, this method supports resource injection if the
given clazz represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • clazz – the Servlet class to instantiate
Type parameters:
  • <T> – the class of the Servlet to create
Throws:
Returns:the new Servlet instance
Since:Servlet 3.0
/**
     * Instantiates the given Servlet class.
     *
     * <p>The returned Servlet instance may be further customized before it
     * is registered with this ServletContext via a call to
     * {@link #addServlet(String,Servlet)}.
     *
     * <p>The given Servlet class must define a zero argument constructor,
     * which is used to instantiate it.
     *
     * <p>This method introspects the given <tt>clazz</tt> for
     * the following annotations:
     * {@link javax.servlet.annotation.ServletSecurity},
     * {@link javax.servlet.annotation.MultipartConfig},
     * <tt>javax.annotation.security.RunAs</tt>, and
     * <tt>javax.annotation.security.DeclareRoles</tt>.
     * In addition, this method supports resource injection if the
     * given <tt>clazz</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param <T> the class of the Servlet to create
     * @param clazz the Servlet class to instantiate
     *
     * @return the new Servlet instance
     *
     * @throws ServletException if the given <tt>clazz</tt> fails to be
     * instantiated
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public <T extends Servlet> T createServlet(Class<T> clazz)
        throws ServletException;


    
Gets the ServletRegistration corresponding to the servlet with the
given servletName.

Params:
  • servletName – the name of a servlet
Throws:
Returns:the (complete or preliminary) ServletRegistration for the
servlet with the given servletName, or null if no
ServletRegistration exists under that name
Since:Servlet 3.0
/**
     * Gets the ServletRegistration corresponding to the servlet with the
     * given <tt>servletName</tt>.
     *
     * @return the (complete or preliminary) ServletRegistration for the
     * servlet with the given <tt>servletName</tt>, or null if no
     * ServletRegistration exists under that name
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @param servletName the name of a servlet
     * @since Servlet 3.0
     */
    public ServletRegistration getServletRegistration(String servletName);


    
Gets a (possibly empty) Map of the ServletRegistration
objects (keyed by servlet name) corresponding to all servlets
registered with this ServletContext.

The returned Map includes the ServletRegistration objects
corresponding to all declared and annotated servlets, as well as the
ServletRegistration objects corresponding to all servlets that have
been added via one of the addServlet and addJspFile
methods.

If permitted, any changes to the returned Map must not affect this
ServletContext.

Throws:
Returns:Map of the (complete and preliminary) ServletRegistration
objects corresponding to all servlets currently registered with this
ServletContext
Since:Servlet 3.0
/**
     * Gets a (possibly empty) Map of the ServletRegistration
     * objects (keyed by servlet name) corresponding to all servlets
     * registered with this ServletContext.
     *
     * <p>The returned Map includes the ServletRegistration objects
     * corresponding to all declared and annotated servlets, as well as the
     * ServletRegistration objects corresponding to all servlets that have
     * been added via one of the <tt>addServlet</tt> and <tt>addJspFile</tt>
     * methods.
     *
     * <p>If permitted, any changes to the returned Map must not affect this
     * ServletContext.
     *
     * @return Map of the (complete and preliminary) ServletRegistration
     * objects corresponding to all servlets currently registered with this
     * ServletContext
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public Map<String, ? extends ServletRegistration> getServletRegistrations();


    
Adds the filter with the given name and class name to this servlet
context.

The registered filter may be further configured via the returned FilterRegistration object. 
The specified className will be loaded using the
classloader associated with the application represented by this
ServletContext.

If this ServletContext already contains a preliminary
FilterRegistration for a filter with the given filterName,
it will be completed (by assigning the given className to it)
and returned.

This method supports resource injection if the class with the
given className represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • filterName – the name of the filter
  • className – the fully qualified class name of the filter
Throws:
Returns:a FilterRegistration object that may be used to further
configure the registered filter, or null if this
ServletContext already contains a complete FilterRegistration for
a filter with the given filterName
Since:Servlet 3.0
/**
     * Adds the filter with the given name and class name to this servlet
     * context.
     *
     * <p>The registered filter may be further configured via the returned
     * {@link FilterRegistration} object.
     *
     * <p>The specified <tt>className</tt> will be loaded using the
     * classloader associated with the application represented by this
     * ServletContext.
     *
     * <p>If this ServletContext already contains a preliminary
     * FilterRegistration for a filter with the given <tt>filterName</tt>,
     * it will be completed (by assigning the given <tt>className</tt> to it)
     * and returned.
     *
     * <p>This method supports resource injection if the class with the
     * given <tt>className</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param filterName the name of the filter
     * @param className the fully qualified class name of the filter
     *
     * @return a FilterRegistration object that may be used to further
     * configure the registered filter, or <tt>null</tt> if this
     * ServletContext already contains a complete FilterRegistration for
     * a filter with the given <tt>filterName</tt>
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws IllegalArgumentException if <code>filterName</code> is null or
     * an empty String
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public FilterRegistration.Dynamic addFilter(
        String filterName, String className);


    
Registers the given filter instance with this ServletContext
under the given filterName.

The registered filter may be further configured via the returned FilterRegistration object. 
If this ServletContext already contains a preliminary
FilterRegistration for a filter with the given filterName,
it will be completed (by assigning the class name of the given filter
instance to it) and returned.

Params:
  • filterName – the name of the filter
  • filter – the filter instance to register
Throws:
Returns:a FilterRegistration object that may be used to further
configure the given filter, or null if this
ServletContext already contains a complete FilterRegistration for a
filter with the given filterName or if the same filter
instance has already been registered with this or another
ServletContext in the same container
Since:Servlet 3.0
/**
     * Registers the given filter instance with this ServletContext
     * under the given <tt>filterName</tt>.
     *
     * <p>The registered filter may be further configured via the returned
     * {@link FilterRegistration} object.
     *
     * <p>If this ServletContext already contains a preliminary
     * FilterRegistration for a filter with the given <tt>filterName</tt>,
     * it will be completed (by assigning the class name of the given filter
     * instance to it) and returned.
     *
     * @param filterName the name of the filter
     * @param filter the filter instance to register
     *
     * @return a FilterRegistration object that may be used to further
     * configure the given filter, or <tt>null</tt> if this
     * ServletContext already contains a complete FilterRegistration for a
     * filter with the given <tt>filterName</tt> or if the same filter
     * instance has already been registered with this or another
     * ServletContext in the same container
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws IllegalArgumentException if <code>filterName</code> is null or
     * an empty String
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public FilterRegistration.Dynamic addFilter(
        String filterName, Filter filter);


    
Adds the filter with the given name and class type to this servlet
context.

The registered filter may be further configured via the returned FilterRegistration object. 
If this ServletContext already contains a preliminary
FilterRegistration for a filter with the given filterName,
it will be completed (by assigning the name of the given
filterClass to it) and returned.

This method supports resource injection if the given
filterClass represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • filterName – the name of the filter
  • filterClass – the class object from which the filter will be
instantiated
Throws:
Returns:a FilterRegistration object that may be used to further
configure the registered filter, or null if this
ServletContext already contains a complete FilterRegistration for a
filter with the given filterName
Since:Servlet 3.0
/**
     * Adds the filter with the given name and class type to this servlet
     * context.
     *
     * <p>The registered filter may be further configured via the returned
     * {@link FilterRegistration} object.
     *
     * <p>If this ServletContext already contains a preliminary
     * FilterRegistration for a filter with the given <tt>filterName</tt>,
     * it will be completed (by assigning the name of the given
     * <tt>filterClass</tt> to it) and returned.
     *
     * <p>This method supports resource injection if the given
     * <tt>filterClass</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param filterName the name of the filter
     * @param filterClass the class object from which the filter will be
     * instantiated
     *
     * @return a FilterRegistration object that may be used to further
     * configure the registered filter, or <tt>null</tt> if this
     * ServletContext already contains a complete FilterRegistration for a
     * filter with the given <tt>filterName</tt>
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws IllegalArgumentException if <code>filterName</code> is null or
     * an empty String
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public FilterRegistration.Dynamic addFilter(String filterName,
        Class <? extends Filter> filterClass);


    
Instantiates the given Filter class.

The returned Filter instance may be further customized before it is registered with this ServletContext via a call to addFilter(String, Filter). 
The given Filter class must define a zero argument constructor,
which is used to instantiate it.

This method supports resource injection if the given
clazz represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • clazz – the Filter class to instantiate
Type parameters:
  • <T> – the class of the Filter to create
Throws:
Returns:the new Filter instance
Since:Servlet 3.0
/**
     * Instantiates the given Filter class.
     *
     * <p>The returned Filter instance may be further customized before it
     * is registered with this ServletContext via a call to
     * {@link #addFilter(String,Filter)}.
     *
     * <p>The given Filter class must define a zero argument constructor,
     * which is used to instantiate it.
     *
     * <p>This method supports resource injection if the given
     * <tt>clazz</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param <T> the class of the Filter to create
     * @param clazz the Filter class to instantiate
     *
     * @return the new Filter instance
     *
     * @throws ServletException if the given <tt>clazz</tt> fails to be
     * instantiated
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public <T extends Filter> T createFilter(Class<T> clazz)
        throws ServletException;


    
Gets the FilterRegistration corresponding to the filter with the
given filterName.

Params:
  • filterName – the name of a filter
Throws:
Returns:the (complete or preliminary) FilterRegistration for the
filter with the given filterName, or null if no
FilterRegistration exists under that name
Since:Servlet 3.0
/**
     * Gets the FilterRegistration corresponding to the filter with the
     * given <tt>filterName</tt>.
     *
     * @param filterName the name of a filter
     * @return the (complete or preliminary) FilterRegistration for the
     * filter with the given <tt>filterName</tt>, or null if no
     * FilterRegistration exists under that name
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public FilterRegistration getFilterRegistration(String filterName);


    
Gets a (possibly empty) Map of the FilterRegistration
objects (keyed by filter name) corresponding to all filters
registered with this ServletContext.

The returned Map includes the FilterRegistration objects
corresponding to all declared and annotated filters, as well as the
FilterRegistration objects corresponding to all filters that have
been added via one of the addFilter methods.

Any changes to the returned Map must not affect this
ServletContext.

Throws:
Returns:Map of the (complete and preliminary) FilterRegistration
objects corresponding to all filters currently registered with this
ServletContext
Since:Servlet 3.0
/**
     * Gets a (possibly empty) Map of the FilterRegistration
     * objects (keyed by filter name) corresponding to all filters
     * registered with this ServletContext.
     *
     * <p>The returned Map includes the FilterRegistration objects
     * corresponding to all declared and annotated filters, as well as the
     * FilterRegistration objects corresponding to all filters that have
     * been added via one of the <tt>addFilter</tt> methods.
     *
     * <p>Any changes to the returned Map must not affect this
     * ServletContext.
     *
     * @return Map of the (complete and preliminary) FilterRegistration
     * objects corresponding to all filters currently registered with this
     * ServletContext
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public Map<String, ? extends FilterRegistration> getFilterRegistrations();


    
Gets the SessionCookieConfig object through which various properties of the session tracking cookies created on behalf of this ServletContext may be configured.

Repeated invocations of this method will return the same
SessionCookieConfig instance.

Throws:
Returns:the SessionCookieConfig object through which
various properties of the session tracking cookies created on
behalf of this ServletContext may be configured
Since:Servlet 3.0
/**
     * Gets the {@link SessionCookieConfig} object through which various
     * properties of the session tracking cookies created on behalf of this
     * <tt>ServletContext</tt> may be configured.
     *
     * <p>Repeated invocations of this method will return the same
     * <tt>SessionCookieConfig</tt> instance.
     *
     * @return the <tt>SessionCookieConfig</tt> object through which
     * various properties of the session tracking cookies created on
     * behalf of this <tt>ServletContext</tt> may be configured
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public SessionCookieConfig getSessionCookieConfig();


    
Sets the session tracking modes that are to become effective for this
ServletContext.

The given sessionTrackingModes replaces any
session tracking modes set by a previous invocation of this
method on this ServletContext.

Params:
  • sessionTrackingModes – the set of session tracking modes to
become effective for this ServletContext
Throws:
Since:Servlet 3.0
/**
     * Sets the session tracking modes that are to become effective for this
     * <tt>ServletContext</tt>.
     *
     * <p>The given <tt>sessionTrackingModes</tt> replaces any
     * session tracking modes set by a previous invocation of this
     * method on this <tt>ServletContext</tt>.
     *
     * @param sessionTrackingModes the set of session tracking modes to
     * become effective for this <tt>ServletContext</tt>
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @throws IllegalArgumentException if <tt>sessionTrackingModes</tt>
     * specifies a combination of <tt>SessionTrackingMode.SSL</tt> with a
     * session tracking mode other than <tt>SessionTrackingMode.SSL</tt>,
     * or if <tt>sessionTrackingModes</tt> specifies a session tracking mode
     * that is not supported by the servlet container
     *
     * @since Servlet 3.0
     */
    public void setSessionTrackingModes(Set<SessionTrackingMode> sessionTrackingModes);


    
Gets the session tracking modes that are supported by default for this
ServletContext.

The returned set is not backed by the ServletContext object, so changes in the returned set are not reflected in the ServletContext object, and vice-versa.


Throws:
Returns:set of the session tracking modes supported by default for
this ServletContext
Since:Servlet 3.0
/**
     * Gets the session tracking modes that are supported by default for this
     * <tt>ServletContext</tt>.
     *
     * <p>The returned set is not backed by the {@code ServletContext} object,
     * so changes in the returned set are not reflected in the
     * {@code ServletContext} object, and vice-versa.</p>
     *
     * @return set of the session tracking modes supported by default for
     * this <tt>ServletContext</tt>
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public Set<SessionTrackingMode> getDefaultSessionTrackingModes();


    
Gets the session tracking modes that are in effect for this
ServletContext.

The session tracking modes in effect are those provided to setSessionTrackingModes. 
The returned set is not backed by the ServletContext object, so changes in the returned set are not reflected in the ServletContext object, and vice-versa.


Throws:
Returns:set of the session tracking modes in effect for this
ServletContext
Since:Servlet 3.0
/**
     * Gets the session tracking modes that are in effect for this
     * <tt>ServletContext</tt>.
     *
     * <p>The session tracking modes in effect are those provided to
     * {@link #setSessionTrackingModes setSessionTrackingModes}.
     *
     * <p>The returned set is not backed by the {@code ServletContext} object,
     * so changes in the returned set are not reflected in the
     * {@code ServletContext} object, and vice-versa.</p>
     *
     * @return set of the session tracking modes in effect for this
     * <tt>ServletContext</tt>
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public Set<SessionTrackingMode> getEffectiveSessionTrackingModes();


    
Adds the listener with the given class name to this ServletContext.

The class with the given name will be loaded using the
classloader associated with the application represented by this
ServletContext, and must implement one or more of the following
interfaces:



If this ServletContext was passed to ServletContainerInitializer.onStartup, then the class with the given name may also implement ServletContextListener, in addition to the interfaces listed above. 
As part of this method call, the container must load the class
with the specified class name to ensure that it implements one of
the required interfaces.

If the class with the given name implements a listener interface whose invocation order corresponds to the declaration order (i.e., if it implements ServletRequestListener, ServletContextListener, or HttpSessionListener), then the new listener will be added to the end of the ordered list of listeners of that interface. 
This method supports resource injection if the class with the
given className represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • className – the fully qualified class name of the listener
Throws:
Since:Servlet 3.0
/**
     * Adds the listener with the given class name to this ServletContext.
     *
     * <p>The class with the given name will be loaded using the
     * classloader associated with the application represented by this
     * ServletContext, and must implement one or more of the following
     * interfaces:
     * <ul>
     * <li>{@link ServletContextAttributeListener}
     * <li>{@link ServletRequestListener}
     * <li>{@link ServletRequestAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionIdListener}
     * <li>{@link javax.servlet.http.HttpSessionListener}
     * </ul>
     *
     * <p>If this ServletContext was passed to
     * {@link ServletContainerInitializer#onStartup}, then the class with
     * the given name may also implement {@link ServletContextListener},
     * in addition to the interfaces listed above.
     *
     * <p>As part of this method call, the container must load the class
     * with the specified class name to ensure that it implements one of
     * the required interfaces.
     *
     * <p>If the class with the given name implements a listener interface
     * whose invocation order corresponds to the declaration order (i.e.,
     * if it implements {@link ServletRequestListener},
     * {@link ServletContextListener}, or
     * {@link javax.servlet.http.HttpSessionListener}),
     * then the new listener will be added to the end of the ordered list of
     * listeners of that interface.
     *
     * <p>This method supports resource injection if the class with the
     * given <tt>className</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param className the fully qualified class name of the listener
     *
     * @throws IllegalArgumentException if the class with the given name
     * does not implement any of the above interfaces, or if it implements
     * {@link ServletContextListener} and this ServletContext was not
     * passed to {@link ServletContainerInitializer#onStartup}
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public void addListener(String className);


    
Adds the given listener to this ServletContext.

The given listener must be an instance of one or more of the
following interfaces:



If this ServletContext was passed to ServletContainerInitializer.onStartup, then the given listener may also be an instance of ServletContextListener, in addition to the interfaces listed above. 
If the given listener is an instance of a listener interface whose invocation order corresponds to the declaration order (i.e., if it is an instance of ServletRequestListener, ServletContextListener, or HttpSessionListener), then the listener will be added to the end of the ordered list of listeners of that interface. 
Params:
  • t – the listener to be added
Type parameters:
  • <T> – the class of the EventListener to add
Throws:
Since:Servlet 3.0
/**
     * Adds the given listener to this ServletContext.
     *
     * <p>The given listener must be an instance of one or more of the
     * following interfaces:
     * <ul>
     * <li>{@link ServletContextAttributeListener}
     * <li>{@link ServletRequestListener}
     * <li>{@link ServletRequestAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionIdListener}
     * <li>{@link javax.servlet.http.HttpSessionListener}
     * </ul>
     *
     * <p>If this ServletContext was passed to
     * {@link ServletContainerInitializer#onStartup}, then the given
     * listener may also be an instance of {@link ServletContextListener},
     * in addition to the interfaces listed above.
     *
     * <p>If the given listener is an instance of a listener interface whose
     * invocation order corresponds to the declaration order (i.e., if it
     * is an instance of {@link ServletRequestListener},
     * {@link ServletContextListener}, or
     * {@link javax.servlet.http.HttpSessionListener}),
     * then the listener will be added to the end of the ordered list of
     * listeners of that interface.
     *
     * @param <T> the class of the EventListener to add
     * @param t the listener to be added
     *
     * @throws IllegalArgumentException if the given listener is not
     * an instance of any of the above interfaces, or if it is an instance
     * of {@link ServletContextListener} and this ServletContext was not
     * passed to {@link ServletContainerInitializer#onStartup}
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public <T extends EventListener> void addListener(T t);


    
Adds a listener of the given class type to this ServletContext.

The given listenerClass must implement one or more of the
following interfaces:



If this ServletContext was passed to ServletContainerInitializer.onStartup, then the given listenerClass may also implement ServletContextListener, in addition to the interfaces listed above. 
If the given listenerClass implements a listener interface whose invocation order corresponds to the declaration order (i.e., if it implements ServletRequestListener, ServletContextListener, or HttpSessionListener), then the new listener will be added to the end of the ordered list of listeners of that interface. 
This method supports resource injection if the given
listenerClass represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • listenerClass – the listener class to be instantiated
Throws:
Since:Servlet 3.0
/**
     * Adds a listener of the given class type to this ServletContext.
     *
     * <p>The given <tt>listenerClass</tt> must implement one or more of the
     * following interfaces:
     * <ul>
     * <li>{@link ServletContextAttributeListener}
     * <li>{@link ServletRequestListener}
     * <li>{@link ServletRequestAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionAttributeListener}
     * <li>{@link javax.servlet.http.HttpSessionIdListener}
     * <li>{@link javax.servlet.http.HttpSessionListener}
     * </ul>
     *
     * <p>If this ServletContext was passed to
     * {@link ServletContainerInitializer#onStartup}, then the given
     * <tt>listenerClass</tt> may also implement
     * {@link ServletContextListener}, in addition to the interfaces listed
     * above.
     *
     * <p>If the given <tt>listenerClass</tt> implements a listener
     * interface whose invocation order corresponds to the declaration order
     * (i.e., if it implements {@link ServletRequestListener},
     * {@link ServletContextListener}, or
     * {@link javax.servlet.http.HttpSessionListener}),
     * then the new listener will be added to the end of the ordered list
     * of listeners of that interface.
     *
     * <p>This method supports resource injection if the given
     * <tt>listenerClass</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param listenerClass the listener class to be instantiated
     *
     * @throws IllegalArgumentException if the given <tt>listenerClass</tt>
     * does not implement any of the above interfaces, or if it implements
     * {@link ServletContextListener} and this ServletContext was not passed
     * to {@link ServletContainerInitializer#onStartup}
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.0
     */
    public void addListener(Class <? extends EventListener> listenerClass);


    
Instantiates the given EventListener class.

The specified EventListener class must implement at least one of the ServletContextListener, ServletContextAttributeListener, ServletRequestListener, ServletRequestAttributeListener, HttpSessionAttributeListener, HttpSessionIdListener, or HttpSessionListener interfaces. 
The returned EventListener instance may be further customized before it is registered with this ServletContext via a call to addListener(EventListener). 
The given EventListener class must define a zero argument
constructor, which is used to instantiate it.

This method supports resource injection if the given
clazz represents a Managed Bean.
See the Java EE platform and JSR 299 specifications for additional
details about Managed Beans and resource injection.

Params:
  • clazz – the EventListener class to instantiate
Type parameters:
  • <T> – the class of the EventListener to create
Throws:
Returns:the new EventListener instance
Since:Servlet 3.0
/**
     * Instantiates the given EventListener class.
     *
     * <p>The specified EventListener class must implement at least one of
     * the {@link ServletContextListener},
     * {@link ServletContextAttributeListener},
     * {@link ServletRequestListener},
     * {@link ServletRequestAttributeListener},
     * {@link javax.servlet.http.HttpSessionAttributeListener},
     * {@link javax.servlet.http.HttpSessionIdListener}, or
     * {@link javax.servlet.http.HttpSessionListener}
     * interfaces.
     *
     * <p>The returned EventListener instance may be further customized
     * before it is registered with this ServletContext via a call to
     * {@link #addListener(EventListener)}.
     *
     * <p>The given EventListener class must define a zero argument
     * constructor, which is used to instantiate it.
     *
     * <p>This method supports resource injection if the given
     * <tt>clazz</tt> represents a Managed Bean.
     * See the Java EE platform and JSR 299 specifications for additional
     * details about Managed Beans and resource injection.
     *
     * @param <T> the class of the EventListener to create
     * @param clazz the EventListener class to instantiate
     *
     * @return the new EventListener instance
     *
     * @throws ServletException if the given <tt>clazz</tt> fails to be
     * instantiated
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @throws IllegalArgumentException if the specified EventListener class
     * does not implement any of the
     * {@link ServletContextListener},
     * {@link ServletContextAttributeListener},
     * {@link ServletRequestListener},
     * {@link ServletRequestAttributeListener},
     * {@link javax.servlet.http.HttpSessionAttributeListener},
     * {@link javax.servlet.http.HttpSessionIdListener}, or
     * {@link javax.servlet.http.HttpSessionListener}
     * interfaces.
     *
     * @since Servlet 3.0
     */
    public <T extends EventListener> T createListener(Class<T> clazz)
        throws ServletException;


    
Gets the <jsp-config> related configuration
that was aggregated from the web.xml and
web-fragment.xml descriptor files of the web application
represented by this ServletContext.

Throws:
See Also:
Returns:the <jsp-config> related configuration
that was aggregated from the web.xml and
web-fragment.xml descriptor files of the web application
represented by this ServletContext, or null if no such configuration
exists
Since:Servlet 3.0
/**
     * Gets the <code>&lt;jsp-config&gt;</code> related configuration
     * that was aggregated from the <code>web.xml</code> and
     * <code>web-fragment.xml</code> descriptor files of the web application
     * represented by this ServletContext.
     *
     * @return the <code>&lt;jsp-config&gt;</code> related configuration
     * that was aggregated from the <code>web.xml</code> and
     * <code>web-fragment.xml</code> descriptor files of the web application
     * represented by this ServletContext, or null if no such configuration
     * exists
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @see javax.servlet.descriptor.JspConfigDescriptor
     *
     * @since Servlet 3.0
     */
    public JspConfigDescriptor getJspConfigDescriptor();


    
Gets the class loader of the web application represented by this
ServletContext.

If a security manager exists, and the caller's class loader
is not the same as, or an ancestor of the requested class loader,
then the security manager's checkPermission method is
called with a RuntimePermission("getClassLoader")
permission to check whether access to the requested class loader
should be granted.

Throws:
Returns:the class loader of the web application represented by this
ServletContext
Since:Servlet 3.0
/**
     * Gets the class loader of the web application represented by this
     * ServletContext.
     *
     * <p>If a security manager exists, and the caller's class loader
     * is not the same as, or an ancestor of the requested class loader,
     * then the security manager's <code>checkPermission</code> method is
     * called with a <code>RuntimePermission("getClassLoader")</code>
     * permission to check whether access to the requested class loader
     * should be granted.
     *
     * @return the class loader of the web application represented by this
     * ServletContext
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @throws SecurityException if a security manager denies access to
     * the requested class loader
     *
     * @since Servlet 3.0
     */
    public ClassLoader getClassLoader();


    
Declares role names that are tested using isUserInRole.

Roles that are implicitly declared as a result of their use within the 
setServletSecurity or 
setRunAsRole methods of the ServletRegistration interface need not be declared. 
Params:
  • roleNames – the role names being declared
Throws:
Since:Servlet 3.0
/**
     * Declares role names that are tested using <code>isUserInRole</code>.
     *
     * <p>Roles that are implicitly declared as a result of their use within
     * the {@link ServletRegistration.Dynamic#setServletSecurity
     * setServletSecurity} or {@link ServletRegistration.Dynamic#setRunAsRole
     * setRunAsRole} methods of the {@link ServletRegistration} interface need
     * not be declared.
     *
     * @param roleNames the role names being declared
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @throws IllegalArgumentException if any of the argument roleNames is
     * null or the empty string
     *
     * @throws IllegalStateException if the ServletContext has already
     * been initialized
     *
     * @since Servlet 3.0
     */
    public void declareRoles(String... roleNames);


    
Returns the configuration name of the logical host on which the
ServletContext is deployed.
Servlet containers may support multiple logical hosts. This method must
return the same name for all the servlet contexts deployed on a logical
host, and the name returned by this method must be distinct, stable per
logical host, and suitable for use in associating server configuration
information with the logical host. The returned value is NOT expected
or required to be equivalent to a network address or hostname of the
logical host.

Throws:
Returns:a String containing the configuration name of the
logical host on which the servlet context is deployed.
Since:Servlet 3.1
/**
     * Returns the configuration name of the logical host on which the
     * ServletContext is deployed.
     *
     * Servlet containers may support multiple logical hosts. This method must
     * return the same name for all the servlet contexts deployed on a logical
     * host, and the name returned by this method must be distinct, stable per
     * logical host, and suitable for use in associating server configuration
     * information with the logical host. The returned value is NOT expected
     * or required to be equivalent to a network address or hostname of the
     * logical host.
     *
     * @return a <code>String</code> containing the configuration name of the
     * logical host on which the servlet context is deployed.
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 3.1
     */
    public String getVirtualServerName();


    
Gets the session timeout in minutes that are supported by default for
this ServletContext.

Throws:
Returns:the session timeout in minutes that are supported by default for
this ServletContext
Since:Servlet 4.0
/**
     * Gets the session timeout in minutes that are supported by default for
     * this <tt>ServletContext</tt>.
     *
     * @return the session timeout in minutes that are supported by default for
     * this <tt>ServletContext</tt>
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public int getSessionTimeout();


    
Sets the session timeout in minutes for this ServletContext.

Params:
  • sessionTimeout – session timeout in minutes
Throws:
Since:Servlet 4.0
/**
     * Sets the session timeout in minutes for this ServletContext.
     *
     * @param sessionTimeout session timeout in minutes
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public void setSessionTimeout(int sessionTimeout);


    
Gets the request character encoding that are supported by default for
this ServletContext. This method returns null if no request
encoding character encoding has been specified in deployment descriptor
or container specific configuration (for all web applications in the
container).

Throws:
Returns:the request character encoding that are supported by default for
this ServletContext
Since:Servlet 4.0
/**
     * Gets the request character encoding that are supported by default for
     * this <tt>ServletContext</tt>. This method returns null if no request
     * encoding character encoding has been specified in deployment descriptor
     * or container specific configuration (for all web applications in the
     * container).
     *
     * @return the request character encoding that are supported by default for
     * this <tt>ServletContext</tt>
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public String getRequestCharacterEncoding();


    
Sets the request character encoding for this ServletContext.

Params:
  • encoding – request character encoding
Throws:
Since:Servlet 4.0
/**
     * Sets the request character encoding for this ServletContext.
     *
     * @param encoding request character encoding
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public void setRequestCharacterEncoding(String encoding);


    
Gets the response character encoding that are supported by default for
this ServletContext. This method returns null if no response
encoding character encoding has been specified in deployment descriptor
or container specific configuration (for all web applications in the
container).

Throws:
Returns:the request character encoding that are supported by default for
this ServletContext
Since:Servlet 4.0
/**
     * Gets the response character encoding that are supported by default for
     * this <tt>ServletContext</tt>. This method returns null if no response
     * encoding character encoding has been specified in deployment descriptor
     * or container specific configuration (for all web applications in the
     * container).
     *
     * @return the request character encoding that are supported by default for
     * this <tt>ServletContext</tt>
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public String getResponseCharacterEncoding();


    
Sets the response character encoding for this ServletContext.

Params:
  • encoding – response character encoding
Throws:
Since:Servlet 4.0
/**
     * Sets the response character encoding for this ServletContext.
     *
     * @param encoding response character encoding
     *
     * @throws IllegalStateException if this ServletContext has already
     * been initialized
     *
     * @throws UnsupportedOperationException if this ServletContext was
     * passed to the {@link ServletContextListener#contextInitialized} method
     * of a {@link ServletContextListener} that was neither declared in
     * <code>web.xml</code> or <code>web-fragment.xml</code>, nor annotated
     * with {@link javax.servlet.annotation.WebListener}
     *
     * @since Servlet 4.0
     */
    public void setResponseCharacterEncoding(String encoding);
}