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 }