javax.servlet.RequestDispatcher Maven / Gradle / Ivy
/*
* The contents of this file are subject to the terms
* of the Common Development and Distribution License
* (the "License"). You may not use this file except
* in compliance with the License.
*
* You can obtain a copy of the license at
* glassfish/bootstrap/legal/CDDLv1.0.txt or
* https://glassfish.dev.java.net/public/CDDLv1.0.html.
* See the License for the specific language governing
* permissions and limitations under the License.
*
* When distributing Covered Code, include this CDDL
* HEADER in each file and include the License file at
* glassfish/bootstrap/legal/CDDLv1.0.txt. If applicable,
* add the following below this CDDL HEADER, with the
* fields enclosed by brackets "[]" replaced with your
* own identifying information: Portions Copyright [yyyy]
* [name of copyright owner]
*
* Copyright 2005 Sun Microsystems, Inc. All rights reserved.
*
* Portions Copyright Apache Software Foundation.
*/
package javax.servlet;
import java.io.IOException;
/**
* Defines an object that receives requests from the client
* and sends them to any resource (such as a servlet,
* HTML file, or JSP file) on the server. The servlet
* container creates the RequestDispatcher object,
* which is used as a wrapper around a server resource located
* at a particular path or given by a particular name.
*
* This interface is intended to wrap servlets,
* but a servlet container can create RequestDispatcher
* objects to wrap any type of resource.
*
* @author Various
*
* @see ServletContext#getRequestDispatcher(java.lang.String)
* @see ServletContext#getNamedDispatcher(java.lang.String)
* @see ServletRequest#getRequestDispatcher(java.lang.String)
*
*/
public interface RequestDispatcher {
/**
* Forwards a request from
* a servlet to another resource (servlet, JSP file, or
* HTML file) on the server. This method allows
* one servlet to do preliminary processing of
* a request and another resource to generate
* the response.
*
*
For a RequestDispatcher obtained via
* getRequestDispatcher(), the ServletRequest
* object has its path elements and parameters adjusted to match
* the path of the target resource.
*
*
forward should be called before the response has been
* committed to the client (before response body output has been flushed).
* If the response already has been committed, this method throws
* an IllegalStateException.
* Uncommitted output in the response buffer is automatically cleared
* before the forward.
*
*
The request and response parameters must be either the same
* objects as were passed to the calling servlet's service method or be
* subclasses of the {@link ServletRequestWrapper} or {@link ServletResponseWrapper} classes
* that wrap them.
*
*
* @param request a {@link ServletRequest} object
* that represents the request the client
* makes of the servlet
*
* @param response a {@link ServletResponse} object
* that represents the response the servlet
* returns to the client
*
* @exception ServletException if the target resource throws this exception
*
* @exception IOException if the target resource throws this exception
*
* @exception IllegalStateException if the response was already committed
*
*/
public void forward(ServletRequest request, ServletResponse response)
throws ServletException, IOException;
/**
*
* Includes the content of a resource (servlet, JSP page,
* HTML file) in the response. In essence, this method enables
* programmatic server-side includes.
*
*
The {@link ServletResponse} object has its path elements
* and parameters remain unchanged from the caller's. The included
* servlet cannot change the response status code or set headers;
* any attempt to make a change is ignored.
*
*
The request and response parameters must be either the same
* objects as were passed to the calling servlet's service method or be
* subclasses of the {@link ServletRequestWrapper} or {@link ServletResponseWrapper} classes
* that wrap them.
*
*
*
* @param request a {@link ServletRequest} object
* that contains the client's request
*
* @param response a {@link ServletResponse} object
* that contains the servlet's response
*
* @exception ServletException if the included resource throws this exception
*
* @exception IOException if the included resource throws this exception
*
*
*/
public void include(ServletRequest request, ServletResponse response)
throws ServletException, IOException;
}