1
2
3 /*
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
5 *
6 * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
7 *
8 * Portions Copyright Apache Software Foundation.
9 *
10 * The contents of this file are subject to the terms of either the GNU
11 * General Public License Version 2 only ("GPL") or the Common Development
12 * and Distribution License("CDDL") (collectively, the "License"). You
13 * may not use this file except in compliance with the License. You can obtain
14 * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
15 * or glassfish/bootstrap/legal/LICENSE.txt. See the License for the specific
16 * language governing permissions and limitations under the License.
17 *
18 * When distributing the software, include this License Header Notice in each
19 * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
20 * Sun designates this particular file as subject to the "Classpath" exception
21 * as provided by Sun in the GPL Version 2 section of the License file that
22 * accompanied this code. If applicable, add the following below the License
23 * Header, with the fields enclosed by brackets [] replaced by your own
24 * identifying information: "Portions Copyrighted [year]
25 * [name of copyright owner]"
26 *
27 * Contributor(s):
28 *
29 * If you wish your version of this file to be governed by only the CDDL or
30 * only the GPL Version 2, indicate your decision by adding "[Contributor]
31 * elects to include this software in this distribution under the [CDDL or GPL
32 * Version 2] license." If you don't indicate a single choice of license, a
33 * recipient has the option to distribute your version of this file under
34 * either the CDDL, the GPL Version 2 or to extend the choice of license to
35 * its licensees as provided above. However, if you add GPL Version 2 code
36 * and therefore, elected the GPL Version 2 license, then the option applies
37 * only if the new code is made subject to such option by the copyright
38 * holder.
39 */
40
41
42 package javax.servlet;
43
44 import java.io.IOException;
45
46
47 /**
48 * Defines an object that receives requests from the client
49 * and sends them to any resource (such as a servlet,
50 * HTML file, or JSP file) on the server. The servlet
51 * container creates the <code>RequestDispatcher</code> object,
52 * which is used as a wrapper around a server resource located
53 * at a particular path or given by a particular name.
54 *
55 * <p>This interface is intended to wrap servlets,
56 * but a servlet container can create <code>RequestDispatcher</code>
57 * objects to wrap any type of resource.
58 *
59 * @author Various
60 *
61 * @see ServletContext#getRequestDispatcher(java.lang.String)
62 * @see ServletContext#getNamedDispatcher(java.lang.String)
63 * @see ServletRequest#getRequestDispatcher(java.lang.String)
64 *
65 */
66
67 public interface RequestDispatcher {
68
69
70
71
72
73 /**
74 * Forwards a request from
75 * a servlet to another resource (servlet, JSP file, or
76 * HTML file) on the server. This method allows
77 * one servlet to do preliminary processing of
78 * a request and another resource to generate
79 * the response.
80 *
81 * <p>For a <code>RequestDispatcher</code> obtained via
82 * <code>getRequestDispatcher()</code>, the <code>ServletRequest</code>
83 * object has its path elements and parameters adjusted to match
84 * the path of the target resource.
85 *
86 * <p><code>forward</code> should be called before the response has been
87 * committed to the client (before response body output has been flushed).
88 * If the response already has been committed, this method throws
89 * an <code>IllegalStateException</code>.
90 * Uncommitted output in the response buffer is automatically cleared
91 * before the forward.
92 *
93 * <p>The request and response parameters must be either the same
94 * objects as were passed to the calling servlet's service method or be
95 * subclasses of the {@link ServletRequestWrapper} or {@link ServletResponseWrapper} classes
96 * that wrap them.
97 *
98 *
99 * @param request a {@link ServletRequest} object
100 * that represents the request the client
101 * makes of the servlet
102 *
103 * @param response a {@link ServletResponse} object
104 * that represents the response the servlet
105 * returns to the client
106 *
107 * @exception ServletException if the target resource throws this exception
108 *
109 * @exception IOException if the target resource throws this exception
110 *
111 * @exception IllegalStateException if the response was already committed
112 *
113 */
114
115 public void forward(ServletRequest request, ServletResponse response)
116 throws ServletException, IOException;
117
118
119
120
121 /**
122 *
123 * Includes the content of a resource (servlet, JSP page,
124 * HTML file) in the response. In essence, this method enables
125 * programmatic server-side includes.
126 *
127 * <p>The {@link ServletResponse} object has its path elements
128 * and parameters remain unchanged from the caller's. The included
129 * servlet cannot change the response status code or set headers;
130 * any attempt to make a change is ignored.
131 *
132 * <p>The request and response parameters must be either the same
133 * objects as were passed to the calling servlet's service method or be
134 * subclasses of the {@link ServletRequestWrapper} or {@link ServletResponseWrapper} classes
135 * that wrap them.
136 *
137 *
138 *
139 * @param request a {@link ServletRequest} object
140 * that contains the client's request
141 *
142 * @param response a {@link ServletResponse} object
143 * that contains the servlet's response
144 *
145 * @exception ServletException if the included resource throws this exception
146 *
147 * @exception IOException if the included resource throws this exception
148 *
149 *
150 */
151
152 public void include(ServletRequest request, ServletResponse response)
153 throws ServletException, IOException;
154 }
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