summaryrefslogtreecommitdiff
path: root/libjava/classpath/java/io/OutputStreamWriter.java
blob: 27067fdb951aaa86d94e356f7a9ecea1f5f3e3c5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
/* OutputStreamWriter.java -- Writer that converts chars to bytes
   Copyright (C) 1998, 1999, 2000, 2001, 2003, 2005  Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath is distributed in the hope that it will be useful, but
WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
02110-1301 USA.

Linking this library statically or dynamically with other modules is
making a combined work based on this library.  Thus, the terms and
conditions of the GNU General Public License cover the whole
combination.

As a special exception, the copyright holders of this library give you
permission to link this library with independent modules to produce an
executable, regardless of the license terms of these independent
modules, and to copy and distribute the resulting executable under
terms of your choice, provided that you also meet, for each linked
independent module, the terms and conditions of the license of that
module.  An independent module is a module which is not derived from
or based on this library.  If you modify this library, you may extend
this exception to your version of the library, but you are not
obligated to do so.  If you do not wish to do so, delete this
exception statement from your version. */


package java.io;

import gnu.java.nio.charset.EncodingHelper;

import java.nio.ByteBuffer;
import java.nio.CharBuffer;
import java.nio.charset.CharacterCodingException;
import java.nio.charset.Charset;
import java.nio.charset.CharsetEncoder;
import java.nio.charset.CodingErrorAction;
import java.nio.charset.MalformedInputException;

/**
 * This class writes characters to an output stream that is byte oriented
 * It converts the chars that are written to bytes using an encoding layer,
 * which is specific to a particular encoding standard.  The desired
 * encoding can either be specified by name, or if no encoding is specified,
 * the system default encoding will be used.  The system default encoding
 * name is determined from the system property <code>file.encoding</code>.
 * The only encodings that are guaranteed to be available are "8859_1"
 * (the Latin-1 character set) and "UTF8".  Unfortunately, Java does not
 * provide a mechanism for listing the encodings that are supported in
 * a given implementation.
 * <p>
 * Here is a list of standard encoding names that may be available:
 * <p>
 * <ul>
 * <li>8859_1 (ISO-8859-1/Latin-1)
 * <li>8859_2 (ISO-8859-2/Latin-2)
 * <li>8859_3 (ISO-8859-3/Latin-3)
 * <li>8859_4 (ISO-8859-4/Latin-4)
 * <li>8859_5 (ISO-8859-5/Latin-5)
 * <li>8859_6 (ISO-8859-6/Latin-6)
 * <li>8859_7 (ISO-8859-7/Latin-7)
 * <li>8859_8 (ISO-8859-8/Latin-8)
 * <li>8859_9 (ISO-8859-9/Latin-9)
 * <li>ASCII (7-bit ASCII)
 * <li>UTF8 (UCS Transformation Format-8)
 * <li>More Later
 * </ul>
 *
 * @author Aaron M. Renn (arenn@urbanophile.com)
 * @author Per Bothner (bothner@cygnus.com)
 * @date April 17, 1998.
 */
public class OutputStreamWriter extends Writer
{
  /**
   * The output stream.
   */
  private OutputStream out;

  /**
   * The charset encoder.
   */
  private final CharsetEncoder encoder;

  /**
   * java.io canonical name of the encoding.
   */
  private final String encodingName;

  /**
   * Buffer output before character conversion as it has costly overhead.
   */
  private final CharBuffer outputBuffer;
  private final static int BUFFER_SIZE = 1024;

  /**
   * This method initializes a new instance of <code>OutputStreamWriter</code>
   * to write to the specified stream using a caller supplied character
   * encoding scheme.  Note that due to a deficiency in the Java language
   * design, there is no way to determine which encodings are supported.
   *
   * @param out The <code>OutputStream</code> to write to
   * @param encoding_scheme The name of the encoding scheme to use for
   * character to byte translation
   *
   * @exception UnsupportedEncodingException If the named encoding is
   * not available.
   */
  public OutputStreamWriter (OutputStream out, String encoding_scheme)
    throws UnsupportedEncodingException
  {
    CharsetEncoder encoder;
    String encodingName;
    this.out = out;
    outputBuffer = CharBuffer.allocate(BUFFER_SIZE);

    try
      {
        // Don't use NIO if avoidable
        if(EncodingHelper.isISOLatin1(encoding_scheme))
          {
            encodingName = "ISO8859_1";
            encoder = null;
          }
       else
         {
           /*
            * Workaround for encodings with a byte-order-mark.
            * We only want to write it once per stream.
            */
           try
             {
               if(encoding_scheme.equalsIgnoreCase("UnicodeBig") ||
                  encoding_scheme.equalsIgnoreCase("UTF-16") ||
                  encoding_scheme.equalsIgnoreCase("UTF16"))
                 {
                   encoding_scheme = "UTF-16BE";
                   out.write((byte)0xFE);
                   out.write((byte)0xFF);
                 }
               else if(encoding_scheme.equalsIgnoreCase("UnicodeLittle"))
                 {
                   encoding_scheme = "UTF-16LE";
                   out.write((byte)0xFF);
                   out.write((byte)0xFE);
                 }
             }
           catch(IOException ioe)
             {
             }

           Charset cs = EncodingHelper.getCharset(encoding_scheme);
           if(cs == null)
             throw new UnsupportedEncodingException("Encoding "+encoding_scheme+
                                                    " unknown");
           encoder = cs.newEncoder();
           encodingName = EncodingHelper.getOldCanonical(cs.name());

           encoder.onMalformedInput(CodingErrorAction.REPLACE);
           encoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
         }
      }
    catch(RuntimeException e)
      {
        // Default to ISO Latin-1, will happen if this is called, for instance,
        //  before the NIO provider is loadable.
        encoder = null;
        encodingName = "ISO8859_1";
      }
    this.encoder = encoder;
    this.encodingName = encodingName;
  }

  /**
   * This method initializes a new instance of <code>OutputStreamWriter</code>
   * to write to the specified stream using the default encoding.
   *
   * @param out The <code>OutputStream</code> to write to
   */
  public OutputStreamWriter (OutputStream out)
  {
    CharsetEncoder encoder;
    String encodingName;
    this.out = out;
    outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
    try
      {
        String encoding = System.getProperty("file.encoding");
        Charset cs = Charset.forName(encoding);
        encoder = cs.newEncoder();
        encodingName =  EncodingHelper.getOldCanonical(cs.name());
      }
    catch(RuntimeException e)
      {
        encoder = null;
        encodingName = "ISO8859_1";
      }

    if(encoder != null)
      {
        encoder.onMalformedInput(CodingErrorAction.REPLACE);
        encoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
      }
    this.encoder = encoder;
    this.encodingName = encodingName;
  }

  /**
   * This method initializes a new instance of <code>OutputStreamWriter</code>
   * to write to the specified stream using a given <code>Charset</code>.
   *
   * @param out The <code>OutputStream</code> to write to
   * @param cs The <code>Charset</code> of the encoding to use
   *
   * @since 1.5
   */
  public OutputStreamWriter(OutputStream out, Charset cs)
  {
    this.out = out;
    encoder = cs.newEncoder();
    encoder.onMalformedInput(CodingErrorAction.REPLACE);
    encoder.onUnmappableCharacter(CodingErrorAction.REPLACE);
    outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
    encodingName = EncodingHelper.getOldCanonical(cs.name());
  }

  /**
   * This method initializes a new instance of <code>OutputStreamWriter</code>
   * to write to the specified stream using a given
   * <code>CharsetEncoder</code>.
   *
   * @param out The <code>OutputStream</code> to write to
   * @param enc The <code>CharsetEncoder</code> to encode the output with
   *
   * @since 1.5
   */
  public OutputStreamWriter(OutputStream out, CharsetEncoder enc)
  {
    this.out = out;
    encoder = enc;
    outputBuffer = CharBuffer.allocate(BUFFER_SIZE);
    Charset cs = enc.charset();
    if (cs == null)
      encodingName = "US-ASCII";
    else
      encodingName = EncodingHelper.getOldCanonical(cs.name());
  }

  /**
   * This method closes this stream, and the underlying
   * <code>OutputStream</code>
   *
   * @exception IOException If an error occurs
   */
  public void close () throws IOException
  {
    if(out == null)
      return;
    flush();
    out.close ();
    out = null;
  }

  /**
   * This method returns the name of the character encoding scheme currently
   * in use by this stream.  If the stream has been closed, then this method
   * may return <code>null</code>.
   *
   * @return The encoding scheme name
   */
  public String getEncoding ()
  {
    return out != null ? encodingName : null;
  }

  /**
   * This method flushes any buffered bytes to the underlying output sink.
   *
   * @exception IOException If an error occurs
   */
  public void flush () throws IOException
  {
      if(out != null){
          if(outputBuffer != null){
              char[] buf = new char[outputBuffer.position()];
              if(buf.length > 0){
                  outputBuffer.flip();
                  outputBuffer.get(buf);
                  writeConvert(buf, 0, buf.length);
                  outputBuffer.clear();
              }
          }
          out.flush ();
      }
  }

  /**
   * This method writes <code>count</code> characters from the specified
   * array to the output stream starting at position <code>offset</code>
   * into the array.
   *
   * @param buf The array of character to write from
   * @param offset The offset into the array to start writing chars from
   * @param count The number of chars to write.
   *
   * @exception IOException If an error occurs
   */
  public void write (char[] buf, int offset, int count) throws IOException
  {
    if(out == null)
      throw new IOException("Stream is closed.");
    if(buf == null)
      throw new IOException("Buffer is null.");

    if(outputBuffer != null)
        {
            if(count >= outputBuffer.remaining())
                {
                    int r = outputBuffer.remaining();
                    outputBuffer.put(buf, offset, r);
                    writeConvert(outputBuffer.array(), 0, BUFFER_SIZE);
                    outputBuffer.clear();
                    offset += r;
                    count -= r;
                    // if the remaining bytes is larger than the whole buffer,
                    // just don't buffer.
                    if(count >= outputBuffer.remaining()){
                      writeConvert(buf, offset, count);
                      return;
                    }
                }
            outputBuffer.put(buf, offset, count);
        } else writeConvert(buf, offset, count);
  }

 /**
  * Converts and writes characters.
  */
  private void writeConvert (char[] buf, int offset, int count)
      throws IOException
  {
    if(encoder == null)
    {
      byte[] b = new byte[count];
      for(int i=0;i<count;i++)
        b[i] = nullConversion(buf[offset+i]);
      out.write(b);
    } else {
      try  {
        ByteBuffer output = encoder.encode(CharBuffer.wrap(buf,offset,count));
        encoder.reset();
        if(output.hasArray())
          out.write(output.array());
        else
          {
            byte[] outbytes = new byte[output.remaining()];
            output.get(outbytes);
            out.write(outbytes);
          }
      } catch(IllegalStateException e) {
        throw new IOException("Internal error.");
      } catch(MalformedInputException e) {
        throw new IOException("Invalid character sequence.");
      } catch(CharacterCodingException e) {
        throw new IOException("Unmappable character.");
      }
    }
  }

  private byte nullConversion(char c) {
          return (byte)((c <= 0xFF)?c:'?');
  }

  /**
   * This method writes <code>count</code> bytes from the specified
   * <code>String</code> starting at position <code>offset</code> into the
   * <code>String</code>.
   *
   * @param str The <code>String</code> to write chars from
   * @param offset The position in the <code>String</code> to start
   * writing chars from
   * @param count The number of chars to write
   *
   * @exception IOException If an error occurs
   */
  public void write (String str, int offset, int count) throws IOException
  {
    if(str == null)
      throw new IOException("String is null.");

    write(str.toCharArray(), offset, count);
  }

  /**
   * This method writes a single character to the output stream.
   *
   * @param ch The char to write, passed as an int.
   *
   * @exception IOException If an error occurs
   */
  public void write (int ch) throws IOException
  {
          // No buffering, no encoding ... just pass through
          if (encoder == null && outputBuffer == null) {
                  out.write(nullConversion((char)ch));
          } else {
                  if (outputBuffer != null) {
                          if (outputBuffer.remaining() == 0) {
                                  writeConvert(outputBuffer.array(), 0, BUFFER_SIZE);
                                  outputBuffer.clear();
                          }
                          outputBuffer.put((char)ch);
                  } else {
                      writeConvert(new char[]{ (char)ch }, 0, 1);
                  }
          }
  }
} // class OutputStreamWriter