https://tomcat.apache.org/: jakarta.servlet package 
/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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 jakarta.servlet;

import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Enumeration;
import java.util.EventListener;
import java.util.Map;
import java.util.Set;

import jakarta.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. 
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.
 *
 * @see Servlet#getServletConfig
 * @see ServletConfig#getServletContext
 */
public interface ServletContext {

    public static final String TEMPDIR = "jakarta.servlet.context.tempdir";

    
Since:Servlet 3.0
/**
     * @since Servlet 3.0
     */
    public static final String ORDERED_LIBS = "jakarta.servlet.context.orderedLibs";

    
Return the main path associated with this context.

Returns:The main context path
Since:Servlet 2.5
/**
     * Return the main path associated with this context.
     *
     * @return The main context path
     *
     * @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 "/", 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 Java Servlet API that this servlet
container supports. All implementations that comply with Version 5.0 must
have this method return the integer 5.

Returns:4
/**
     * Returns the major version of the Java Servlet API that this servlet
     * container supports. All implementations that comply with Version 5.0 must
     * have this method return the integer 5.
     *
     * @return 4
     */
    public int getMajorVersion();

    
Returns the minor version of the Servlet API that this servlet container
supports. All implementations that comply with Version 5.0 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 5.0 must have this
     * method return the integer 0.
     *
     * @return 0
     */
    public int getMinorVersion();

    
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/**
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     *
     * @since Servlet 3.0 TODO SERVLET3 - Add comments
     */
    public int getEffectiveMajorVersion();

    
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/**
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0 TODO SERVLET3 - Add comments
     */
    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 are "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 are <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 and
have a leading '/'. 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,



getResourcePaths("/") returns {"/welcome.html", "/catalog/",
"/customer/", "/WEB-INF/"}

getResourcePaths("/catalog/") returns {"/catalog/index.html",
"/catalog/products.html", "/catalog/offers/"}.


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. Paths indicating subdirectory paths end with a '/'. The
     * returned paths are all relative to the root of the web application and
     * have a leading '/'. For example, for a web application containing<br>
     * <br>
     * /welcome.html<br>
     * /catalog/index.html<br>
     * /catalog/products.html<br>
     * /catalog/offers/books.html<br>
     * /catalog/offers/music.html<br>
     * /customer/login.jsp<br>
     * /WEB-INF/web.xml<br>
     * /WEB-INF/classes/com.acme.OrderServlet.class,<br>
     * <br>
     * getResourcePaths("/") returns {"/welcome.html", "/catalog/",
     * "/customer/", "/WEB-INF/"}<br>
     * getResourcePaths("/catalog/") returns {"/catalog/index.html",
     * "/catalog/products.html", "/catalog/offers/"}.<br>
     *
     * @param path
     *            the partial path used to match the resources, which must start
     *            with a /
     * @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 a specified path. The
path must begin with a "/" and is interpreted as relative to the current
context root.


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 a specified path. The
     * path must begin with a "/" and is interpreted as relative to the current
     * context root.
     * <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 "/" 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. 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);

    
Do not use. 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.

Params:
  • name – Not used
Throws:
Returns:Always null
Deprecated:As of Java Servlet API 2.1, with no direct replacement.
/**
     * Do not use. 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 Not used
     *
     * @return Always <code>null</code>
     *
     * @throws ServletException never
     *
     * @deprecated As of Java Servlet API 2.1, with no direct replacement.
     */
    @Deprecated
    public Servlet getServlet(String name) throws ServletException;

    
Do not use. 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:Always and empty Enumeration
Deprecated:As of Java Servlet API 2.0, with no replacement.
/**
     * Do not use. 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 Always and empty Enumeration
     *
     * @deprecated As of Java Servlet API 2.0, with no replacement.
     */
    @Deprecated
    public Enumeration<Servlet> getServlets();

    
Do not use. 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:Always and empty Enumeration
Deprecated:As of Java Servlet API 2.1, with no replacement.
/**
     * Do not use. 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 Always and empty Enumeration
     *
     * @deprecated As of Java Servlet API 2.1, with no replacement.
     */
    @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);

    
Do not use.

Params:
  • exception – The exception to log
  • msg –       The message to log with 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.
/**
     * Do not use.
     * @param exception The exception to log
     * @param msg       The message to log with the exception
     * @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.
     */
    @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);

    
Returns a String containing the real path for a given
virtual path. For example, the path "/index.html" returns the absolute
file path on the server's filesystem would be served by a request for
"http://host/contextPath/index.html", where contextPath is 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. This method returns null if the
servlet container cannot translate the virtual path to a real path for
any reason (such as when the content is being made available from a
.war archive).

Params:
  • path – 
           a String specifying a virtual path
Returns:a String specifying the real path, or null if the
        translation cannot be performed
/**
     * Returns a <code>String</code> containing the real path for a given
     * virtual path. For example, the path "/index.html" returns the absolute
     * file path on the server's filesystem would be served by a request for
     * "http://host/contextPath/index.html", where contextPath is 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. This method returns <code>null</code> if the
     * servlet container cannot translate the virtual path to a real path for
     * any reason (such as when the content is being made available from a
     * <code>.war</code> archive).
     *
     * @param path
     *            a <code>String</code> specifying a virtual path
     * @return a <code>String</code> specifying the real path, or null 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 initialization
        parameter
/**
     * 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 initialization
     *         parameter
     * @throws NullPointerException If the provided parameter name is
     *         <code>null</code>
     * @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();

    
Set the given initialisation parameter to the given value.

Params:
  • name –  Name of initialisation parameter
  • value – Value for initialisation parameter
Throws:
Returns:true if the call succeeds or false if
        the call fails because an initialisation parameter with the same
        name has already been set
Since:Servlet 3.0
/**
     * Set the given initialisation parameter to the given value.
     * @param name  Name of initialisation parameter
     * @param value Value for initialisation parameter
     * @return <code>true</code> if the call succeeds or <code>false</code> if
     *         the call fails because an initialisation parameter with the same
     *         name has already been set
     * @throws IllegalStateException If initialisation of this ServletContext
     *         has already completed
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws NullPointerException If the provided parameter name is
     *         <code>null</code>
     * @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. 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. 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
     * @throws NullPointerException If the provided attribute name is
     *         <code>null</code>
     * @see ServletContext#getAttributeNames
     */
    public Object getAttribute(String name);

    
Returns an Enumeration containing the attribute names available within this servlet context. 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 servlet context. 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 servlet context. 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 servlet context. 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 provided attribute name is
     *         <code>null</code>
     */
    public void setAttribute(String name, Object object);

    
Removes the attribute with the given name from the servlet context. 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 the servlet context. 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();

    
Register a servlet implementation for use in this ServletContext.

Params:
  • servletName – The name of the servlet to register
  • className –   The implementation class for the servlet
Throws:
Returns:The registration object that enables further configuration
Since:Servlet 3.0
/**
     * Register a servlet implementation for use in this ServletContext.
     * @param servletName The name of the servlet to register
     * @param className   The implementation class for the servlet
     * @return The registration object that enables further configuration
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public ServletRegistration.Dynamic addServlet(String servletName, String className);

    
Register a servlet instance for use in this ServletContext.

Params:
  • servletName – The name of the servlet to register
  • servlet –     The Servlet instance to register
Throws:
Returns:The registration object that enables further configuration
Since:Servlet 3.0
/**
     * Register a servlet instance for use in this ServletContext.
     * @param servletName The name of the servlet to register
     * @param servlet     The Servlet instance to register
     * @return The registration object that enables further configuration
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public ServletRegistration.Dynamic addServlet(String servletName, Servlet servlet);

    
Add servlet to context.

Params:
  • servletName –  Name of servlet to add
  • servletClass – Class of servlet to add
Throws:
Returns: null if the servlet has already been fully defined, else a Dynamic object that can be used to further configure the servlet
Since:Servlet 3.0
/**
     * Add servlet to context.
     * @param   servletName  Name of servlet to add
     * @param   servletClass Class of servlet to add
     * @return  <code>null</code> if the servlet has already been fully defined,
     *          else a {@link jakarta.servlet.ServletRegistration.Dynamic} object
     *          that can be used to further configure the servlet
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public ServletRegistration.Dynamic addServlet(String servletName,
            Class<? extends Servlet> servletClass);

    
Params:
  • jspName –   The servlet name under which this JSP file should be
                 registered
  • jspFile –   The path, relative to the web application root, for the
                 JSP file to be used for this servlet
Returns: a Dynamic object that can be used to further configure the servlet
Since:Servlet 4.0
/**
     *
     * @param jspName   The servlet name under which this JSP file should be
     *                  registered
     * @param jspFile   The path, relative to the web application root, for the
     *                  JSP file to be used for this servlet
     *
     * @return  a {@link jakarta.servlet.ServletRegistration.Dynamic} object
     *          that can be used to further configure the servlet
     *
     * @since Servlet 4.0
     */
    public ServletRegistration.Dynamic addJspFile(String jspName, String jspFile);

    
TODO SERVLET3 - Add comments

Params:
  • c –   TODO
Type parameters:
  • <T> – TODO
Throws:
Returns:TODO
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @param <T> TODO
     * @param c   TODO
     * @return TODO
     * @throws ServletException TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public <T extends Servlet> T createServlet(Class<T> c)
            throws ServletException;

    
Obtain the details of the named servlet.

Params:
  • servletName –   The name of the Servlet of interest
Throws:
Returns: The registration details for the named Servlet or
         null if no Servlet has been registered with the
         given name
Since:Servlet 3.0
/**
     * Obtain the details of the named servlet.
     *
     * @param servletName   The name of the Servlet of interest
     *
     * @return  The registration details for the named Servlet or
     *          <code>null</code> if no Servlet has been registered with the
     *          given name
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     *
     * @since Servlet 3.0
     */
    public ServletRegistration getServletRegistration(String servletName);

    
TODO SERVLET3 - Add comments

Throws:
Returns:TODO
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public Map<String, ? extends ServletRegistration> getServletRegistrations();

    
Add filter to context.

Params:
  • filterName –  Name of filter to add
  • className – Name of filter class
Throws:
Returns: null if the filter has already been fully defined, else a Dynamic object that can be used to further configure the filter
Since:Servlet 3.0
/**
     * Add filter to context.
     * @param   filterName  Name of filter to add
     * @param   className Name of filter class
     * @return  <code>null</code> if the filter has already been fully defined,
     *          else a {@link jakarta.servlet.FilterRegistration.Dynamic} object
     *          that can be used to further configure the filter
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @since Servlet 3.0
     */
    public FilterRegistration.Dynamic addFilter(String filterName, String className);

    
Add filter to context.

Params:
  • filterName –  Name of filter to add
  • filter –      Filter to add
Throws:
Returns: null if the filter has already been fully defined, else a Dynamic object that can be used to further configure the filter
Since:Servlet 3.0
/**
     * Add filter to context.
     * @param   filterName  Name of filter to add
     * @param   filter      Filter to add
     * @return  <code>null</code> if the filter has already been fully defined,
     *          else a {@link jakarta.servlet.FilterRegistration.Dynamic} object
     *          that can be used to further configure the filter
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @since Servlet 3.0
     */
    public FilterRegistration.Dynamic addFilter(String filterName, Filter filter);

    
Add filter to context.

Params:
  • filterName –  Name of filter to add
  • filterClass – Class of filter to add
Throws:
Returns: null if the filter has already been fully defined, else a Dynamic object that can be used to further configure the filter
Since:Servlet 3.0
/**
     * Add filter to context.
     * @param   filterName  Name of filter to add
     * @param   filterClass Class of filter to add
     * @return  <code>null</code> if the filter has already been fully defined,
     *          else a {@link jakarta.servlet.FilterRegistration.Dynamic} object
     *          that can be used to further configure the filter
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @since Servlet 3.0
     */
    public FilterRegistration.Dynamic addFilter(String filterName,
            Class<? extends Filter> filterClass);

    
TODO SERVLET3 - Add comments

Params:
  • c –   TODO
Type parameters:
  • <T> – TODO
Throws:
Returns:TODO
Since:Servlet 3.
/**
     * TODO SERVLET3 - Add comments
     * @param <T> TODO
     * @param c   TODO
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws ServletException TODO
     * @since Servlet 3.
     */
    public <T extends Filter> T createFilter(Class<T> c) throws ServletException;

    
TODO SERVLET3 - Add comments

Params:
  • filterName – TODO
Throws:
Returns:TODO
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @param filterName TODO
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public FilterRegistration getFilterRegistration(String filterName);

    
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/**
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0 TODO SERVLET3 - Add comments
     */
    public Map<String, ? extends FilterRegistration> getFilterRegistrations();

    
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/**
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0 TODO SERVLET3 - Add comments
     */
    public SessionCookieConfig getSessionCookieConfig();

    
Configures the available session tracking modes for this web application.

Params:
  • sessionTrackingModes – The session tracking modes to use for this
       web application
Throws:
Since:Servlet 3.0
/**
     * Configures the available session tracking modes for this web application.
     * @param sessionTrackingModes The session tracking modes to use for this
     *        web application
     * @throws IllegalArgumentException
     *             If sessionTrackingModes specifies
     *             {@link SessionTrackingMode#SSL} in combination with any other
     *             {@link SessionTrackingMode}
     * @throws IllegalStateException
     *             If the context has already been initialised
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public void setSessionTrackingModes(
            Set<SessionTrackingMode> sessionTrackingModes);

    
Obtains the default session tracking modes for this web application. By default SessionTrackingMode.URL is always supported, SessionTrackingMode.COOKIE is supported unless the cookies
attribute has been set to false for the context and SessionTrackingMode.SSL is supported if at least one of the connectors used by this context has the attribute secure set to
true.

Throws:
Returns:The set of default session tracking modes for this web
        application
Since:Servlet 3.0
/**
     * Obtains the default session tracking modes for this web application.
     * By default {@link SessionTrackingMode#URL} is always supported, {@link
     * SessionTrackingMode#COOKIE} is supported unless the <code>cookies</code>
     * attribute has been set to <code>false</code> for the context and {@link
     * SessionTrackingMode#SSL} is supported if at least one of the connectors
     * used by this context has the attribute <code>secure</code> set to
     * <code>true</code>.
     * @return The set of default session tracking modes for this web
     *         application
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public Set<SessionTrackingMode> getDefaultSessionTrackingModes();

    
Obtains the currently enabled session tracking modes for this web
application.

Throws:
Returns:The value supplied via setSessionTrackingModes(Set<SessionTrackingMode>) if one was previously set, else return the defaults
Since:Servlet 3.0
/**
     * Obtains the currently enabled session tracking modes for this web
     * application.
     * @return The value supplied via {@link #setSessionTrackingModes(Set)} if
     *         one was previously set, else return the defaults
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public Set<SessionTrackingMode> getEffectiveSessionTrackingModes();

    
TODO SERVLET3 - Add comments

Params:
  • className – TODO
Throws:
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @param className TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public void addListener(String className);

    
TODO SERVLET3 - Add comments

Params:
  • t –   TODO
Type parameters:
  • <T> – TODO
Throws:
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @param <T> TODO
     * @param t   TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public <T extends EventListener> void addListener(T t);

    
TODO SERVLET3 - Add comments

Params:
  • listenerClass – TODO
Throws:
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @param listenerClass TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public void addListener(Class<? extends EventListener> listenerClass);

    
TODO SERVLET3 - Add comments

Params:
  • c – TODO
Type parameters:
  • <T> – TODO
Throws:
Returns:TODO
Since:Servlet 3.0
/**
     * TODO SERVLET3 - Add comments
     * @param <T> TODO
     * @param c TODO
     * @return TODO
     * @throws ServletException TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0
     */
    public <T extends EventListener> T createListener(Class<T> c)
            throws ServletException;

    
Throws:
Returns:TODO
Since:Servlet 3.0 TODO SERVLET3 - Add comments
/**
     * @return TODO
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @since Servlet 3.0 TODO SERVLET3 - Add comments
     */
    public JspConfigDescriptor getJspConfigDescriptor();

    
Get the web application class loader associated with this ServletContext.

Throws:
Returns:The associated web application class loader
Since:Servlet 3.0
/**
     * Get the web application class loader associated with this ServletContext.
     *
     * @return The associated web application class loader
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws SecurityException if access to the class loader is prevented by a
     *         SecurityManager
     * @since Servlet 3.0
     */
    public ClassLoader getClassLoader();

    
Add to the declared roles for this ServletContext.

Params:
  • roleNames – The roles to add
Throws:
Since:Servlet 3.0
/**
     * Add to the declared roles for this ServletContext.
     * @param roleNames The roles to add
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalArgumentException If the list of roleNames is null or
     *         empty
     * @throws IllegalStateException If the ServletContext has already been
     *         initialised
     * @since Servlet 3.0
     */
    public void declareRoles(String... roleNames);

    
Get the primary name of the virtual host on which this context is
deployed. The name may or may not be a valid host name.

Returns:The primary name of the virtual host on which this context is
        deployed
Since:Servlet 3.1
/**
     * Get the primary name of the virtual host on which this context is
     * deployed. The name may or may not be a valid host name.
     *
     * @return The primary name of the virtual host on which this context is
     *         deployed
     * @since Servlet 3.1
     */
    public String getVirtualServerName();

    
Get the default session timeout.

Throws:
Returns:The current default session timeout in minutes
Since:Servlet 4.0
/**
     * Get the default session timeout.
     *
     * @return The current default session timeout in minutes
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     *
     * @since Servlet 4.0
     */
    public int getSessionTimeout();

    
Set the default session timeout. This method may only be called before
the ServletContext is initialised.

Params:
  • sessionTimeout – The new default session timeout in minutes.
Throws:
Since:Servlet 4.0
/**
     * Set the default session timeout. This method may only be called before
     * the ServletContext is initialised.
     *
     * @param sessionTimeout The new default session timeout in minutes.
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalStateException If the ServletContext has already been
     *         initialised
     *
     * @since Servlet 4.0
     */
    public void setSessionTimeout(int sessionTimeout);

    
Get the default character encoding for reading request bodies.

Throws:
Returns:The character encoding name or null if no default has been specified
Since:Servlet 4.0
/**
     * Get the default character encoding for reading request bodies.
     *
     * @return The character encoding name or {@code null} if no default has
     *         been specified
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     *
     * @since Servlet 4.0
     */
    public String getRequestCharacterEncoding();

    
Set the default character encoding to use for reading request bodies.
Calling this method will over-ride any value set in the deployment
descriptor.

Params:
  • encoding – The name of the character encoding to use
Throws:
Since:Servlet 4.0
/**
     * Set the default character encoding to use for reading request bodies.
     * Calling this method will over-ride any value set in the deployment
     * descriptor.
     *
     * @param encoding The name of the character encoding to use
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalStateException If the ServletContext has already been
     *         initialised
     *
     * @since Servlet 4.0
     */
    public void setRequestCharacterEncoding(String encoding);

    
Get the default character encoding for writing response bodies.

Throws:
Returns:The character encoding name or null if no default has been specified
Since:Servlet 4.0
/**
     * Get the default character encoding for writing response bodies.
     *
     * @return The character encoding name or {@code null} if no default has
     *         been specified
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     *
     * @since Servlet 4.0
     */
    public String getResponseCharacterEncoding();

    
Set the default character encoding to use for writing response bodies.
Calling this method will over-ride any value set in the deployment
descriptor.

Params:
  • encoding – The name of the character encoding to use
Throws:
Since:Servlet 4.0
/**
     * Set the default character encoding to use for writing response bodies.
     * Calling this method will over-ride any value set in the deployment
     * descriptor.
     *
     * @param encoding The name of the character encoding to use
     *
     * @throws UnsupportedOperationException    If called from a
     *    {@link ServletContextListener#contextInitialized(ServletContextEvent)}
     *    method of a {@link ServletContextListener} that was not defined in a
     *    web.xml file, a web-fragment.xml file nor annotated with
     *    {@link jakarta.servlet.annotation.WebListener}. For example, a
     *    {@link ServletContextListener} defined in a TLD would not be able to
     *    use this method.
     * @throws IllegalStateException If the ServletContext has already been
     *         initialised
     *
     * @since Servlet 4.0
     */
    public void setResponseCharacterEncoding(String encoding);
}