1 /*

     2  * Copyright (c) 2005, 2008, 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.httpserver;

    27 

    28 import java.io.*;

    29 import java.net.*;

    30 import com.sun.net.httpserver.*;

    31 import com.sun.net.httpserver.spi.*;

    32 

    33 /**

    34  * a class which allows the caller to write an arbitrary

    35  * number of bytes to an underlying stream.

    36  * normal close() does not close the underlying stream

    37  *

    38  * This class is buffered.

    39  *

    40  * Each chunk is written in one go as :-

    41  * abcd\r\nxxxxxxxxxxxxxx\r\n

    42  *

    43  * abcd is the chunk-size, and xxx is the chunk data

    44  * If the length is less than 4 chars (in size) then the buffer

    45  * is written with an offset.

    46  * Final chunk is:

    47  * 0\r\n\r\n

    48  */

    49 

    50 class ChunkedOutputStream extends FilterOutputStream

    51 {

    52     private boolean closed = false;

    53     /* max. amount of user data per chunk */

    54     final static int CHUNK_SIZE = 4096;

    55     /* allow 4 bytes for chunk-size plus 4 for CRLFs */

    56     final static int OFFSET = 6; /* initial <=4 bytes for len + CRLF */

    57     private int pos = OFFSET;

    58     private int count = 0;

    59     private byte[] buf = new byte [CHUNK_SIZE+OFFSET+2];

    60     ExchangeImpl t;

    61 

    62     ChunkedOutputStream (ExchangeImpl t, OutputStream src) {

    63         super (src);

    64         this.t = t;

    65     }

    66 

    67     public void write (int b) throws IOException {

    68         if (closed) {

    69             throw new StreamClosedException ();

    70         }

    71         buf [pos++] = (byte)b;

    72         count ++;

    73         if (count == CHUNK_SIZE) {

    74             writeChunk();

    75         }

    76         assert count < CHUNK_SIZE;

    77     }

    78 

    79     public void write (byte[]b, int off, int len) throws IOException {

    80         if (closed) {

    81             throw new StreamClosedException ();

    82         }

    83         int remain = CHUNK_SIZE - count;

    84         if (len > remain) {

    85             System.arraycopy (b,off,buf,pos,remain);

    86             count = CHUNK_SIZE;

    87             writeChunk();

    88             len -= remain;

    89             off += remain;

    90             while (len >= CHUNK_SIZE) {

    91                 System.arraycopy (b,off,buf,OFFSET,CHUNK_SIZE);

    92                 len -= CHUNK_SIZE;

    93                 off += CHUNK_SIZE;

    94                 count = CHUNK_SIZE;

    95                 writeChunk();

    96             }

    97         }

    98         if (len > 0) {

    99             System.arraycopy (b,off,buf,pos,len);

   100             count += len;

   101             pos += len;

   102         }

   103         if (count == CHUNK_SIZE) {

   104             writeChunk();

   105         }

   106     }

   107 

   108     /**

   109      * write out a chunk , and reset the pointers

   110      * chunk does not have to be CHUNK_SIZE bytes

   111      * count must == number of user bytes (<= CHUNK_SIZE)

   112      */

   113     private void writeChunk () throws IOException {

   114         char[] c = Integer.toHexString (count).toCharArray();

   115         int clen = c.length;

   116         int startByte = 4 - clen;

   117         int i;

   118         for (i=0; i<clen; i++) {

   119             buf[startByte+i] = (byte)c[i];

   120         }

   121         buf[startByte + (i++)] = '\r';

   122         buf[startByte + (i++)] = '\n';

   123         buf[startByte + (i++) + count] = '\r';

   124         buf[startByte + (i++) + count] = '\n';

   125         out.write (buf, startByte, i+count);

   126         count = 0;

   127         pos = OFFSET;

   128     }

   129 

   130     public void close () throws IOException {

   131         if (closed) {

   132             return;

   133         }

   134         flush();

   135         try {

   136             /* write an empty chunk */

   137             writeChunk();

   138             out.flush();

   139             LeftOverInputStream is = t.getOriginalInputStream();

   140             if (!is.isClosed()) {

   141                 is.close();

   142             }

   143         /* some clients close the connection before empty chunk is sent */

   144         } catch (IOException e) {

   145 

   146         } finally {

   147             closed = true;

   148         }

   149 

   150         WriteFinishedEvent e = new WriteFinishedEvent (t);

   151         t.getHttpContext().getServerImpl().addEvent (e);

   152     }

   153 

   154     public void flush () throws IOException {

   155         if (closed) {

   156             throw new StreamClosedException ();

   157         }

   158         if (count > 0) {

   159             writeChunk();

   160         }

   161         out.flush();

   162     }

   163 }