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1   /*
2    * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
3    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4    *
5    * This code is free software; you can redistribute it and/or modify it
6    * under the terms of the GNU General Public License version 2 only, as
7    * published by the Free Software Foundation.  Oracle designates this
8    * particular file as subject to the "Classpath" exception as provided
9    * by Oracle in the LICENSE file that accompanied this code.
10   *
11   * This code is distributed in the hope that it will be useful, but WITHOUT
12   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14   * version 2 for more details (a copy is included in the LICENSE file that
15   * accompanied this code).
16   *
17   * You should have received a copy of the GNU General Public License version
18   * 2 along with this work; if not, write to the Free Software Foundation,
19   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20   *
21   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22   * or visit www.oracle.com if you need additional information or have any
23   * questions.
24   */
25  
26  package sun.net.www.http;
27  
28  import java.io.*;
29  import java.net.*;
30  
31  /**
32   * Instances of this class are returned to applications for the purpose of
33   * sending user data for a HTTP request (excluding TRACE). This class is used
34   * when the content-length will be specified in the header of the request.
35   * The semantics of ByteArrayOutputStream are extended so that
36   * when close() is called, it is no longer possible to write
37   * additional data to the stream. From this point the content length of
38   * the request is fixed and cannot change.
39   *
40   * @author Michael McMahon
41   */
42  
43  public class PosterOutputStream extends ByteArrayOutputStream {
44  
45      private boolean closed;
46  
47      /**
48       * Creates a new output stream for POST user data
49       */
50      public PosterOutputStream () {
51          super (256);
52      }
53  
54      /**
55       * Writes the specified byte to this output stream.
56       *
57       * @param   b   the byte to be written.
58       */
59      public synchronized void write(int b) {
60          if (closed) {
61              return;
62          }
63          super.write (b);
64      }
65  
66      /**
67       * Writes <code>len</code> bytes from the specified byte array
68       * starting at offset <code>off</code> to this output stream.
69       *
70       * @param   b     the data.
71       * @param   off   the start offset in the data.
72       * @param   len   the number of bytes to write.
73       */
74      public synchronized void write(byte b[], int off, int len) {
75          if (closed) {
76              return;
77          }
78          super.write (b, off, len);
79      }
80  
81      /**
82       * Resets the <code>count</code> field of this output
83       * stream to zero, so that all currently accumulated output in the
84       * output stream is discarded. The output stream can be used again,
85       * reusing the already allocated buffer space. If the output stream
86       * has been closed, then this method has no effect.
87       *
88       * @see     java.io.ByteArrayInputStream#count
89       */
90      public synchronized void reset() {
91          if (closed) {
92              return;
93          }
94          super.reset ();
95      }
96  
97      /**
98       * After close() has been called, it is no longer possible to write
99       * to this stream. Further calls to write will have no effect.
100      */
101     public synchronized void close() throws IOException {
102         closed = true;
103         super.close ();
104     }
105 }