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1 /*
2 * ========================================================================
3 *
4 * Licensed to the Apache Software Foundation (ASF) under one or more
5 * contributor license agreements. See the NOTICE file distributed with
6 * this work for additional information regarding copyright ownership.
7 * The ASF licenses this file to You under the Apache License, Version 2.0
8 * (the "License"); you may not use this file except in compliance with
9 * the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing, software
14 * distributed under the License is distributed on an "AS IS" BASIS,
15 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
16 * See the License for the specific language governing permissions and
17 * limitations under the License.
18 *
19 * ========================================================================
20 */
21 package org.apache.cactus.sample.servlet.util;
22
23 import java.io.ByteArrayOutputStream;
24 import java.io.PrintWriter;
25
26 import javax.servlet.ServletOutputStream;
27 import javax.servlet.http.HttpServletResponse;
28 import javax.servlet.http.HttpServletResponseWrapper;
29
30 /**
31 * Wrapper around a <code>HttpServletResponse</code> that we use to easily
32 * write filters that manipulate the output stream. Indeed, we cannot pass
33 * the output stream of our filter direectly to the next filter in the chain
34 * because then we won't be able to write to it (the response will have been
35 * committed). Instead, we pass this wrapper class and then copy its data
36 * to our filter output stream.
37 *
38 * Note: This code was adapted from the Filter tutorial found
39 * {@link <a href="http://www.orionserver.com/tutorials/filters/lesson3/">
40 * here</a>}
41 *
42 * @version $Id: GenericResponseWrapper.java 238816 2004-02-29 16:36:46Z vmassol $
43 *
44 * @see FilterServletOutputStream
45 */
46 public class GenericResponseWrapper extends HttpServletResponseWrapper
47 {
48 /**
49 * Holder for the output data
50 */
51 private ByteArrayOutputStream output;
52
53 /**
54 * Save the content length so that we can query it at a later time
55 * (otherwise it would not be possible as
56 * <code>HttpServletResponseWrapper</code> does not have a method to get
57 * the content length).
58 */
59 private int contentLength;
60
61 /**
62 * Save the content type so that we can query it at a later time
63 * (otherwise it would not be possible as
64 * <code>HttpServletResponseWrapper</code> does not have a method to get
65 * the content type).
66 */
67 private String contentType;
68
69 // Constructors ----------------------------------------------------------
70
71 /**
72 * @param theResponse the wrapped response object
73 */
74 public GenericResponseWrapper(HttpServletResponse theResponse)
75 {
76 super(theResponse);
77 this.output = new ByteArrayOutputStream();
78 }
79
80 // New methods -----------------------------------------------------------
81
82 /**
83 * @return the data sent to the output stream
84 */
85 public byte[] getData()
86 {
87 return output.toByteArray();
88 }
89
90 // Overridden methods ----------------------------------------------------
91
92 /**
93 * @see HttpServletResponseWrapper#getOutputStream()
94 */
95 public ServletOutputStream getOutputStream()
96 {
97 return new FilterServletOutputStream(this.output);
98 }
99
100 /**
101 * @see HttpServletResponseWrapper#setContentLength(int)
102 */
103 public void setContentLength(int theLength)
104 {
105 this.contentLength = theLength;
106 super.setContentLength(theLength);
107 }
108
109 /**
110 * @see HttpServletResponseWrapper#getContentLength()
111 */
112 public int getContentLength()
113 {
114 return this.contentLength;
115 }
116
117 /**
118 * @see HttpServletResponseWrapper#setContentType(String)
119 */
120 public void setContentType(String theType)
121 {
122 this.contentType = theType;
123 super.setContentType(theType);
124 }
125
126 /**
127 * @see HttpServletResponseWrapper#getContentType()
128 */
129 public String getContentType()
130 {
131 return this.contentType;
132 }
133
134 /**
135 * @see HttpServletResponseWrapper#getWriter()
136 */
137 public PrintWriter getWriter()
138 {
139 return new PrintWriter(getOutputStream(), true);
140 }
141 }