/* * The Apache Software License, Version 1.1 * * Copyright (c) 1999 The Apache Software Foundation. All rights * reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. The end-user documentation included with the redistribution, if * any, must include the following acknowlegement: * "This product includes software developed by the * Apache Software Foundation (http://www.apache.org/)." * Alternately, this acknowlegement may appear in the software itself, * if and wherever such third-party acknowlegements normally appear. * * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software * Foundation" must not be used to endorse or promote products derived * from this software without prior written permission. For written * permission, please contact apache@apache.org. * * 5. Products derived from this software may not be called "Apache" * nor may "Apache" appear in their names without prior written * permission of the Apache Group. * * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * ==================================================================== * * This software consists of voluntary contributions made by many * individuals on behalf of the Apache Software Foundation. For more * information on the Apache Software Foundation, please see * . * * ==================================================================== * * This source code implements specifications defined by the Java * Community Process. In order to remain compliant with the specification * DO NOT add / change / or delete method signatures! */ 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 * @version $Version$ * * @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; }