https://projects.eclipse.org/projects/ee4j.servlet: Provides, via submodules, a base configuration for JBoss project builds, as well as a derived configuration supporting multi-release JARs (JBoss by Red Hat)
  • Ed Burns
  • Shing Wai Chan 
/*
 * Copyright (c) 2017, 2018 Oracle and/or its affiliates and others.
 * All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Public License v. 2.0, which is available at
 * http://www.eclipse.org/legal/epl-2.0.
 *
 * This Source Code may also be made available under the following Secondary
 * Licenses when the conditions for such availability set forth in the
 * Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
 * version 2 with the GNU Classpath Exception, which is available at
 * https://www.gnu.org/software/classpath/license.html.
 *
 * SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
 */

package javax.servlet;

import java.util.Map;
import java.util.Set;


Interface through which a Servlet or Filter may be further configured. 
 A Registration object whose getClassName method returns null is considered preliminary. Servlets and
Filters whose implementation class is container implementation specific may be declared without any
servlet-class or filter-class elements, respectively, and will be represented as preliminary
Registration objects. Preliminary registrations must be completed by calling one of the addServlet or
addFilter methods on ServletContext, and passing in the Servlet or Filter name (obtained via getName) along with the supporting Servlet or Filter implementation class name, Class object, or instance, respectively. In most cases, preliminary registrations will be completed by an appropriate, container-provided ServletContainerInitializer. 
Since:Servlet 3.0
/**
 * Interface through which a {@link Servlet} or {@link Filter} may be further configured.
 *
 * <p>
 * A Registration object whose {@link #getClassName} method returns null is considered <i>preliminary</i>. Servlets and
 * Filters whose implementation class is container implementation specific may be declared without any
 * <tt>servlet-class</tt> or <tt>filter-class</tt> elements, respectively, and will be represented as preliminary
 * Registration objects. Preliminary registrations must be completed by calling one of the <tt>addServlet</tt> or
 * <tt>addFilter</tt> methods on {@link ServletContext}, and passing in the Servlet or Filter name (obtained via
 * {@link #getName}) along with the supporting Servlet or Filter implementation class name, Class object, or instance,
 * respectively. In most cases, preliminary registrations will be completed by an appropriate, container-provided
 * {@link ServletContainerInitializer}.
 *
 * @since Servlet 3.0
 */
public interface Registration {

    
Gets the name of the Servlet or Filter that is represented by this Registration.

Returns:the name of the Servlet or Filter that is represented by this Registration
/**
     * Gets the name of the Servlet or Filter that is represented by this Registration.
     *
     * @return the name of the Servlet or Filter that is represented by this Registration
     */
    public String getName();

    
Gets the fully qualified class name of the Servlet or Filter that is represented by this Registration.

Returns:the fully qualified class name of the Servlet or Filter that is represented by this Registration, or null
        if this Registration is preliminary
/**
     * Gets the fully qualified class name of the Servlet or Filter that is represented by this Registration.
     *
     * @return the fully qualified class name of the Servlet or Filter that is represented by this Registration, or null
     *         if this Registration is preliminary
     */
    public String getClassName();

    
Sets the initialization parameter with the given name and value on the Servlet or Filter that is represented by
this Registration.

Params:
  • name –  the initialization parameter name
  • value – the initialization parameter value
Throws:
Returns:true if the update was successful, i.e., an initialization parameter with the given name did not already
        exist for the Servlet or Filter represented by this Registration, and false otherwise
/**
     * Sets the initialization parameter with the given name and value on the Servlet or Filter that is represented by
     * this Registration.
     *
     * @param name  the initialization parameter name
     * @param value the initialization parameter value
     *
     * @return true if the update was successful, i.e., an initialization parameter with the given name did not already
     *         exist for the Servlet or Filter represented by this Registration, and false otherwise
     *
     * @throws IllegalStateException    if the ServletContext from which this Registration was obtained has already been
     *                                  initialized
     * @throws IllegalArgumentException if the given name or value is <tt>null</tt>
     */
    public boolean setInitParameter(String name, String value);

    
Gets the value of the initialization parameter with the given name that will be used to initialize the Servlet or
Filter represented by this Registration object.

Params:
  • name – the name of the initialization parameter whose value is requested
Returns:the value of the initialization parameter with the given name, or null if no initialization
        parameter with the given name exists
/**
     * Gets the value of the initialization parameter with the given name that will be used to initialize the Servlet or
     * Filter represented by this Registration object.
     *
     * @param name the name of the initialization parameter whose value is requested
     *
     * @return the value of the initialization parameter with the given name, or <tt>null</tt> if no initialization
     *         parameter with the given name exists
     */
    public String getInitParameter(String name);

    
Sets the given initialization parameters on the Servlet or Filter that is represented by this Registration.


The given map of initialization parameters is processed by-value, i.e., for each initialization parameter contained in the map, this method calls setInitParameter(String, String). If that method would return false for any of the initialization parameters in the given map, no updates will be performed, and false will be returned. Likewise, if the map contains an initialization parameter with a null name or value, no
updates will be performed, and an IllegalArgumentException will be thrown.

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


Params:
  • initParameters – the initialization parameters
Throws:
  • IllegalStateException –    if the ServletContext from which this Registration was obtained has already been
                                 initialized
  • IllegalArgumentException – if the given map contains an initialization parameter with a null name
                                 or value
Returns:the (possibly empty) Set of initialization parameter names that are in conflict
/**
     * Sets the given initialization parameters on the Servlet or Filter that is represented by this Registration.
     *
     * <p>
     * The given map of initialization parameters is processed <i>by-value</i>, i.e., for each initialization parameter
     * contained in the map, this method calls {@link #setInitParameter(String,String)}. If that method would return
     * false for any of the initialization parameters in the given map, no updates will be performed, and false will be
     * returned. Likewise, if the map contains an initialization parameter with a <tt>null</tt> name or value, no
     * updates will be performed, and an IllegalArgumentException will be thrown.
     *
     * <p>
     * The returned set is not backed by the {@code Registration} object, so changes in the returned set are not
     * reflected in the {@code Registration} object, and vice-versa.
     * </p>
     *
     * @param initParameters the initialization parameters
     *
     * @return the (possibly empty) Set of initialization parameter names that are in conflict
     *
     * @throws IllegalStateException    if the ServletContext from which this Registration was obtained has already been
     *                                  initialized
     * @throws IllegalArgumentException if the given map contains an initialization parameter with a <tt>null</tt> name
     *                                  or value
     */
    public Set<String> setInitParameters(Map<String, String> initParameters);

    
Gets an immutable (and possibly empty) Map containing the currently available initialization parameters that will
be used to initialize the Servlet or Filter represented by this Registration object.

Returns:Map containing the currently available initialization parameters that will be used to initialize the
        Servlet or Filter represented by this Registration object
/**
     * Gets an immutable (and possibly empty) Map containing the currently available initialization parameters that will
     * be used to initialize the Servlet or Filter represented by this Registration object.
     *
     * @return Map containing the currently available initialization parameters that will be used to initialize the
     *         Servlet or Filter represented by this Registration object
     */
    public Map<String, String> getInitParameters();

    
Interface through which a Servlet or Filter registered via one of the addServlet or
addFilter methods, respectively, on ServletContext may be further configured. 
/**
     * Interface through which a {@link Servlet} or {@link Filter} registered via one of the <tt>addServlet</tt> or
     * <tt>addFilter</tt> methods, respectively, on {@link ServletContext} may be further configured.
     */
    interface Dynamic extends Registration {

        
Configures the Servlet or Filter represented by this dynamic Registration as supporting asynchronous
operations or not.


By default, servlet and filters do not support asynchronous operations.


A call to this method overrides any previous setting.

Params:
  • isAsyncSupported – true if the Servlet or Filter represented by this dynamic Registration supports
                        asynchronous operations, false otherwise
Throws:
  • IllegalStateException – if the ServletContext from which this dynamic Registration was obtained has
                              already been initialized
/**
         * Configures the Servlet or Filter represented by this dynamic Registration as supporting asynchronous
         * operations or not.
         *
         * <p>
         * By default, servlet and filters do not support asynchronous operations.
         *
         * <p>
         * A call to this method overrides any previous setting.
         *
         * @param isAsyncSupported true if the Servlet or Filter represented by this dynamic Registration supports
         *                         asynchronous operations, false otherwise
         *
         * @throws IllegalStateException if the ServletContext from which this dynamic Registration was obtained has
         *                               already been initialized
         */
        public void setAsyncSupported(boolean isAsyncSupported);
    }
}