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| 1 | +/* | |
| 2 | + * Copyright (c) 2000, 2009, 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 java.nio.channels; | |
| 27 | + | |
| 28 | +import java.io.FileInputStream; | |
| 29 | +import java.io.FileOutputStream; | |
| 30 | +import java.io.InputStream; | |
| 31 | +import java.io.OutputStream; | |
| 32 | +import java.io.Reader; | |
| 33 | +import java.io.Writer; | |
| 34 | +import java.io.IOException; | |
| 35 | +import java.nio.ByteBuffer; | |
| 36 | +import java.nio.charset.Charset; | |
| 37 | +import java.nio.charset.CharsetDecoder; | |
| 38 | +import java.nio.charset.CharsetEncoder; | |
| 39 | +import java.nio.charset.UnsupportedCharsetException; | |
| 40 | +import java.nio.channels.spi.AbstractInterruptibleChannel; | |
| 41 | +import java.util.concurrent.ExecutionException; | |
| 42 | +import sun.nio.ch.ChannelInputStream; | |
| 43 | +import sun.nio.cs.StreamDecoder; | |
| 44 | +import sun.nio.cs.StreamEncoder; | |
| 45 | + | |
| 46 | + | |
| 47 | +/** | |
| 48 | + * Utility methods for channels and streams. | |
| 49 | + * | |
| 50 | + * <p> This class defines static methods that support the interoperation of the | |
| 51 | + * stream classes of the <tt>{@link java.io}</tt> package with the channel | |
| 52 | + * classes of this package. </p> | |
| 53 | + * | |
| 54 | + * | |
| 55 | + * @author Mark Reinhold | |
| 56 | + * @author Mike McCloskey | |
| 57 | + * @author JSR-51 Expert Group | |
| 58 | + * @since 1.4 | |
| 59 | + */ | |
| 60 | + | |
| 61 | +public final class Channels { | |
| 62 | + | |
| 63 | + private Channels() { } // No instantiation | |
| 64 | + | |
| 65 | + private static void checkNotNull(Object o, String name) { | |
| 66 | + if (o == null) | |
| 67 | + throw new NullPointerException("\"" + name + "\" is null!"); | |
| 68 | + } | |
| 69 | + | |
| 70 | + /** | |
| 71 | + * Write all remaining bytes in buffer to the given channel. | |
| 72 | + * If the channel is selectable then it must be configured blocking. | |
| 73 | + */ | |
| 74 | + private static void writeFullyImpl(WritableByteChannel ch, ByteBuffer bb) | |
| 75 | + throws IOException | |
| 76 | + { | |
| 77 | + while (bb.remaining() > 0) { | |
| 78 | + int n = ch.write(bb); | |
| 79 | + if (n <= 0) | |
| 80 | + throw new RuntimeException("no bytes written"); | |
| 81 | + } | |
| 82 | + } | |
| 83 | + | |
| 84 | + /** | |
| 85 | + * Write all remaining bytes in buffer to the given channel. | |
| 86 | + * | |
| 87 | + * @throws IllegalBlockingException | |
| 88 | + * If the channel is selectable and configured non-blocking. | |
| 89 | + */ | |
| 90 | + private static void writeFully(WritableByteChannel ch, ByteBuffer bb) | |
| 91 | + throws IOException | |
| 92 | + { | |
| 93 | + if (ch instanceof SelectableChannel) { | |
| 94 | + SelectableChannel sc = (SelectableChannel)ch; | |
| 95 | + synchronized (sc.blockingLock()) { | |
| 96 | + if (!sc.isBlocking()) | |
| 97 | + throw new IllegalBlockingModeException(); | |
| 98 | + writeFullyImpl(ch, bb); | |
| 99 | + } | |
| 100 | + } else { | |
| 101 | + writeFullyImpl(ch, bb); | |
| 102 | + } | |
| 103 | + } | |
| 104 | + | |
| 105 | + // -- Byte streams from channels -- | |
| 106 | + | |
| 107 | + /** | |
| 108 | + * Constructs a stream that reads bytes from the given channel. | |
| 109 | + * | |
| 110 | + * <p> The <tt>read</tt> methods of the resulting stream will throw an | |
| 111 | + * {@link IllegalBlockingModeException} if invoked while the underlying | |
| 112 | + * channel is in non-blocking mode. The stream will not be buffered, and | |
| 113 | + * it will not support the {@link InputStream#mark mark} or {@link | |
| 114 | + * InputStream#reset reset} methods. The stream will be safe for access by | |
| 115 | + * multiple concurrent threads. Closing the stream will in turn cause the | |
| 116 | + * channel to be closed. </p> | |
| 117 | + * | |
| 118 | + * @param ch | |
| 119 | + * The channel from which bytes will be read | |
| 120 | + * | |
| 121 | + * @return A new input stream | |
| 122 | + */ | |
| 123 | + public static InputStream newInputStream(ReadableByteChannel ch) { | |
| 124 | + checkNotNull(ch, "ch"); | |
| 125 | + return new sun.nio.ch.ChannelInputStream(ch); | |
| 126 | + } | |
| 127 | + | |
| 128 | + /** | |
| 129 | + * Constructs a stream that writes bytes to the given channel. | |
| 130 | + * | |
| 131 | + * <p> The <tt>write</tt> methods of the resulting stream will throw an | |
| 132 | + * {@link IllegalBlockingModeException} if invoked while the underlying | |
| 133 | + * channel is in non-blocking mode. The stream will not be buffered. The | |
| 134 | + * stream will be safe for access by multiple concurrent threads. Closing | |
| 135 | + * the stream will in turn cause the channel to be closed. </p> | |
| 136 | + * | |
| 137 | + * @param ch | |
| 138 | + * The channel to which bytes will be written | |
| 139 | + * | |
| 140 | + * @return A new output stream | |
| 141 | + */ | |
| 142 | + public static OutputStream newOutputStream(final WritableByteChannel ch) { | |
| 143 | + checkNotNull(ch, "ch"); | |
| 144 | + | |
| 145 | + return new OutputStream() { | |
| 146 | + | |
| 147 | + private ByteBuffer bb = null; | |
| 148 | + private byte[] bs = null; // Invoker's previous array | |
| 149 | + private byte[] b1 = null; | |
| 150 | + | |
| 151 | + public synchronized void write(int b) throws IOException { | |
| 152 | + if (b1 == null) | |
| 153 | + b1 = new byte[1]; | |
| 154 | + b1[0] = (byte)b; | |
| 155 | + this.write(b1); | |
| 156 | + } | |
| 157 | + | |
| 158 | + public synchronized void write(byte[] bs, int off, int len) | |
| 159 | + throws IOException | |
| 160 | + { | |
| 161 | + if ((off < 0) || (off > bs.length) || (len < 0) || | |
| 162 | + ((off + len) > bs.length) || ((off + len) < 0)) { | |
| 163 | + throw new IndexOutOfBoundsException(); | |
| 164 | + } else if (len == 0) { | |
| 165 | + return; | |
| 166 | + } | |
| 167 | + ByteBuffer bb = ((this.bs == bs) | |
| 168 | + ? this.bb | |
| 169 | + : ByteBuffer.wrap(bs)); | |
| 170 | + bb.limit(Math.min(off + len, bb.capacity())); | |
| 171 | + bb.position(off); | |
| 172 | + this.bb = bb; | |
| 173 | + this.bs = bs; | |
| 174 | + Channels.writeFully(ch, bb); | |
| 175 | + } | |
| 176 | + | |
| 177 | + public void close() throws IOException { | |
| 178 | + ch.close(); | |
| 179 | + } | |
| 180 | + | |
| 181 | + }; | |
| 182 | + } | |
| 183 | + | |
| 184 | + /** | |
| 185 | + * Constructs a stream that reads bytes from the given channel. | |
| 186 | + * | |
| 187 | + * <p> The stream will not be buffered, and it will not support the {@link | |
| 188 | + * InputStream#mark mark} or {@link InputStream#reset reset} methods. The | |
| 189 | + * stream will be safe for access by multiple concurrent threads. Closing | |
| 190 | + * the stream will in turn cause the channel to be closed. </p> | |
| 191 | + * | |
| 192 | + * @param ch | |
| 193 | + * The channel from which bytes will be read | |
| 194 | + * | |
| 195 | + * @return A new input stream | |
| 196 | + * | |
| 197 | + * @since 1.7 | |
| 198 | + */ | |
| 199 | + public static InputStream newInputStream(final AsynchronousByteChannel ch) { | |
| 200 | + checkNotNull(ch, "ch"); | |
| 201 | + return new InputStream() { | |
| 202 | + | |
| 203 | + private ByteBuffer bb = null; | |
| 204 | + private byte[] bs = null; // Invoker's previous array | |
| 205 | + private byte[] b1 = null; | |
| 206 | + | |
| 207 | + @Override | |
| 208 | + public synchronized int read() throws IOException { | |
| 209 | + if (b1 == null) | |
| 210 | + b1 = new byte[1]; | |
| 211 | + int n = this.read(b1); | |
| 212 | + if (n == 1) | |
| 213 | + return b1[0] & 0xff; | |
| 214 | + return -1; | |
| 215 | + } | |
| 216 | + | |
| 217 | + @Override | |
| 218 | + public synchronized int read(byte[] bs, int off, int len) | |
| 219 | + throws IOException | |
| 220 | + { | |
| 221 | + if ((off < 0) || (off > bs.length) || (len < 0) || | |
| 222 | + ((off + len) > bs.length) || ((off + len) < 0)) { | |
| 223 | + throw new IndexOutOfBoundsException(); | |
| 224 | + } else if (len == 0) | |
| 225 | + return 0; | |
| 226 | + | |
| 227 | + ByteBuffer bb = ((this.bs == bs) | |
| 228 | + ? this.bb | |
| 229 | + : ByteBuffer.wrap(bs)); | |
| 230 | + bb.position(off); | |
| 231 | + bb.limit(Math.min(off + len, bb.capacity())); | |
| 232 | + this.bb = bb; | |
| 233 | + this.bs = bs; | |
| 234 | + | |
| 235 | + boolean interrupted = false; | |
| 236 | + try { | |
| 237 | + for (;;) { | |
| 238 | + try { | |
| 239 | + return ch.read(bb).get(); | |
| 240 | + } catch (ExecutionException ee) { | |
| 241 | + throw new IOException(ee.getCause()); | |
| 242 | + } catch (InterruptedException ie) { | |
| 243 | + interrupted = true; | |
| 244 | + } | |
| 245 | + } | |
| 246 | + } finally { | |
| 247 | + if (interrupted) | |
| 248 | + Thread.currentThread().interrupt(); | |
| 249 | + } | |
| 250 | + } | |
| 251 | + | |
| 252 | + @Override | |
| 253 | + public void close() throws IOException { | |
| 254 | + ch.close(); | |
| 255 | + } | |
| 256 | + }; | |
| 257 | + } | |
| 258 | + | |
| 259 | + /** | |
| 260 | + * Constructs a stream that writes bytes to the given channel. | |
| 261 | + * | |
| 262 | + * <p> The stream will not be buffered. The stream will be safe for access | |
| 263 | + * by multiple concurrent threads. Closing the stream will in turn cause | |
| 264 | + * the channel to be closed. </p> | |
| 265 | + * | |
| 266 | + * @param ch | |
| 267 | + * The channel to which bytes will be written | |
| 268 | + * | |
| 269 | + * @return A new output stream | |
| 270 | + * | |
| 271 | + * @since 1.7 | |
| 272 | + */ | |
| 273 | + public static OutputStream newOutputStream(final AsynchronousByteChannel ch) { | |
| 274 | + checkNotNull(ch, "ch"); | |
| 275 | + return new OutputStream() { | |
| 276 | + | |
| 277 | + private ByteBuffer bb = null; | |
| 278 | + private byte[] bs = null; // Invoker's previous array | |
| 279 | + private byte[] b1 = null; | |
| 280 | + | |
| 281 | + @Override | |
| 282 | + public synchronized void write(int b) throws IOException { | |
| 283 | + if (b1 == null) | |
| 284 | + b1 = new byte[1]; | |
| 285 | + b1[0] = (byte)b; | |
| 286 | + this.write(b1); | |
| 287 | + } | |
| 288 | + | |
| 289 | + @Override | |
| 290 | + public synchronized void write(byte[] bs, int off, int len) | |
| 291 | + throws IOException | |
| 292 | + { | |
| 293 | + if ((off < 0) || (off > bs.length) || (len < 0) || | |
| 294 | + ((off + len) > bs.length) || ((off + len) < 0)) { | |
| 295 | + throw new IndexOutOfBoundsException(); | |
| 296 | + } else if (len == 0) { | |
| 297 | + return; | |
| 298 | + } | |
| 299 | + ByteBuffer bb = ((this.bs == bs) | |
| 300 | + ? this.bb | |
| 301 | + : ByteBuffer.wrap(bs)); | |
| 302 | + bb.limit(Math.min(off + len, bb.capacity())); | |
| 303 | + bb.position(off); | |
| 304 | + this.bb = bb; | |
| 305 | + this.bs = bs; | |
| 306 | + | |
| 307 | + boolean interrupted = false; | |
| 308 | + try { | |
| 309 | + while (bb.remaining() > 0) { | |
| 310 | + try { | |
| 311 | + ch.write(bb).get(); | |
| 312 | + } catch (ExecutionException ee) { | |
| 313 | + throw new IOException(ee.getCause()); | |
| 314 | + } catch (InterruptedException ie) { | |
| 315 | + interrupted = true; | |
| 316 | + } | |
| 317 | + } | |
| 318 | + } finally { | |
| 319 | + if (interrupted) | |
| 320 | + Thread.currentThread().interrupt(); | |
| 321 | + } | |
| 322 | + } | |
| 323 | + | |
| 324 | + @Override | |
| 325 | + public void close() throws IOException { | |
| 326 | + ch.close(); | |
| 327 | + } | |
| 328 | + }; | |
| 329 | + } | |
| 330 | + | |
| 331 | + | |
| 332 | + // -- Channels from streams -- | |
| 333 | + | |
| 334 | + /** | |
| 335 | + * Constructs a channel that reads bytes from the given stream. | |
| 336 | + * | |
| 337 | + * <p> The resulting channel will not be buffered; it will simply redirect | |
| 338 | + * its I/O operations to the given stream. Closing the channel will in | |
| 339 | + * turn cause the stream to be closed. </p> | |
| 340 | + * | |
| 341 | + * @param in | |
| 342 | + * The stream from which bytes are to be read | |
| 343 | + * | |
| 344 | + * @return A new readable byte channel | |
| 345 | + */ | |
| 346 | + public static ReadableByteChannel newChannel(final InputStream in) { | |
| 347 | + checkNotNull(in, "in"); | |
| 348 | + | |
| 349 | + if (in instanceof FileInputStream && | |
| 350 | + FileInputStream.class.equals(in.getClass())) { | |
| 351 | + return ((FileInputStream)in).getChannel(); | |
| 352 | + } | |
| 353 | + | |
| 354 | + return new ReadableByteChannelImpl(in); | |
| 355 | + } | |
| 356 | + | |
| 357 | + private static class ReadableByteChannelImpl | |
| 358 | + extends AbstractInterruptibleChannel // Not really interruptible | |
| 359 | + implements ReadableByteChannel | |
| 360 | + { | |
| 361 | + InputStream in; | |
| 362 | + private static final int TRANSFER_SIZE = 8192; | |
| 363 | + private byte buf[] = new byte[0]; | |
| 364 | + private boolean open = true; | |
| 365 | + private Object readLock = new Object(); | |
| 366 | + | |
| 367 | + ReadableByteChannelImpl(InputStream in) { | |
| 368 | + this.in = in; | |
| 369 | + } | |
| 370 | + | |
| 371 | + public int read(ByteBuffer dst) throws IOException { | |
| 372 | + int len = dst.remaining(); | |
| 373 | + int totalRead = 0; | |
| 374 | + int bytesRead = 0; | |
| 375 | + synchronized (readLock) { | |
| 376 | + while (totalRead < len) { | |
| 377 | + int bytesToRead = Math.min((len - totalRead), | |
| 378 | + TRANSFER_SIZE); | |
| 379 | + if (buf.length < bytesToRead) | |
| 380 | + buf = new byte[bytesToRead]; | |
| 381 | + if ((totalRead > 0) && !(in.available() > 0)) | |
| 382 | + break; // block at most once | |
| 383 | + try { | |
| 384 | + begin(); | |
| 385 | + bytesRead = in.read(buf, 0, bytesToRead); | |
| 386 | + } finally { | |
| 387 | + end(bytesRead > 0); | |
| 388 | + } | |
| 389 | + if (bytesRead < 0) | |
| 390 | + break; | |
| 391 | + else | |
| 392 | + totalRead += bytesRead; | |
| 393 | + dst.put(buf, 0, bytesRead); | |
| 394 | + } | |
| 395 | + if ((bytesRead < 0) && (totalRead == 0)) | |
| 396 | + return -1; | |
| 397 | + | |
| 398 | + return totalRead; | |
| 399 | + } | |
| 400 | + } | |
| 401 | + | |
| 402 | + protected void implCloseChannel() throws IOException { | |
| 403 | + in.close(); | |
| 404 | + open = false; | |
| 405 | + } | |
| 406 | + } | |
| 407 | + | |
| 408 | + | |
| 409 | + /** | |
| 410 | + * Constructs a channel that writes bytes to the given stream. | |
| 411 | + * | |
| 412 | + * <p> The resulting channel will not be buffered; it will simply redirect | |
| 413 | + * its I/O operations to the given stream. Closing the channel will in | |
| 414 | + * turn cause the stream to be closed. </p> | |
| 415 | + * | |
| 416 | + * @param out | |
| 417 | + * The stream to which bytes are to be written | |
| 418 | + * | |
| 419 | + * @return A new writable byte channel | |
| 420 | + */ | |
| 421 | + public static WritableByteChannel newChannel(final OutputStream out) { | |
| 422 | + checkNotNull(out, "out"); | |
| 423 | + | |
| 424 | + if (out instanceof FileOutputStream && | |
| 425 | + FileOutputStream.class.equals(out.getClass())) { | |
| 426 | + return ((FileOutputStream)out).getChannel(); | |
| 427 | + } | |
| 428 | + | |
| 429 | + return new WritableByteChannelImpl(out); | |
| 430 | + } | |
| 431 | + | |
| 432 | + private static class WritableByteChannelImpl | |
| 433 | + extends AbstractInterruptibleChannel // Not really interruptible | |
| 434 | + implements WritableByteChannel | |
| 435 | + { | |
| 436 | + OutputStream out; | |
| 437 | + private static final int TRANSFER_SIZE = 8192; | |
| 438 | + private byte buf[] = new byte[0]; | |
| 439 | + private boolean open = true; | |
| 440 | + private Object writeLock = new Object(); | |
| 441 | + | |
| 442 | + WritableByteChannelImpl(OutputStream out) { | |
| 443 | + this.out = out; | |
| 444 | + } | |
| 445 | + | |
| 446 | + public int write(ByteBuffer src) throws IOException { | |
| 447 | + int len = src.remaining(); | |
| 448 | + int totalWritten = 0; | |
| 449 | + synchronized (writeLock) { | |
| 450 | + while (totalWritten < len) { | |
| 451 | + int bytesToWrite = Math.min((len - totalWritten), | |
| 452 | + TRANSFER_SIZE); | |
| 453 | + if (buf.length < bytesToWrite) | |
| 454 | + buf = new byte[bytesToWrite]; | |
| 455 | + src.get(buf, 0, bytesToWrite); | |
| 456 | + try { | |
| 457 | + begin(); | |
| 458 | + out.write(buf, 0, bytesToWrite); | |
| 459 | + } finally { | |
| 460 | + end(bytesToWrite > 0); | |
| 461 | + } | |
| 462 | + totalWritten += bytesToWrite; | |
| 463 | + } | |
| 464 | + return totalWritten; | |
| 465 | + } | |
| 466 | + } | |
| 467 | + | |
| 468 | + protected void implCloseChannel() throws IOException { | |
| 469 | + out.close(); | |
| 470 | + open = false; | |
| 471 | + } | |
| 472 | + } | |
| 473 | + | |
| 474 | + | |
| 475 | + // -- Character streams from channels -- | |
| 476 | + | |
| 477 | + /** | |
| 478 | + * Constructs a reader that decodes bytes from the given channel using the | |
| 479 | + * given decoder. | |
| 480 | + * | |
| 481 | + * <p> The resulting stream will contain an internal input buffer of at | |
| 482 | + * least <tt>minBufferCap</tt> bytes. The stream's <tt>read</tt> methods | |
| 483 | + * will, as needed, fill the buffer by reading bytes from the underlying | |
| 484 | + * channel; if the channel is in non-blocking mode when bytes are to be | |
| 485 | + * read then an {@link IllegalBlockingModeException} will be thrown. The | |
| 486 | + * resulting stream will not otherwise be buffered, and it will not support | |
| 487 | + * the {@link Reader#mark mark} or {@link Reader#reset reset} methods. | |
| 488 | + * Closing the stream will in turn cause the channel to be closed. </p> | |
| 489 | + * | |
| 490 | + * @param ch | |
| 491 | + * The channel from which bytes will be read | |
| 492 | + * | |
| 493 | + * @param dec | |
| 494 | + * The charset decoder to be used | |
| 495 | + * | |
| 496 | + * @param minBufferCap | |
| 497 | + * The minimum capacity of the internal byte buffer, | |
| 498 | + * or <tt>-1</tt> if an implementation-dependent | |
| 499 | + * default capacity is to be used | |
| 500 | + * | |
| 501 | + * @return A new reader | |
| 502 | + */ | |
| 503 | + public static Reader newReader(ReadableByteChannel ch, | |
| 504 | + CharsetDecoder dec, | |
| 505 | + int minBufferCap) | |
| 506 | + { | |
| 507 | + checkNotNull(ch, "ch"); | |
| 508 | + return StreamDecoder.forDecoder(ch, dec.reset(), minBufferCap); | |
| 509 | + } | |
| 510 | + | |
| 511 | + /** | |
| 512 | + * Constructs a reader that decodes bytes from the given channel according | |
| 513 | + * to the named charset. | |
| 514 | + * | |
| 515 | + * <p> An invocation of this method of the form | |
| 516 | + * | |
| 517 | + * <blockquote><pre> | |
| 518 | + * Channels.newReader(ch, csname)</pre></blockquote> | |
| 519 | + * | |
| 520 | + * behaves in exactly the same way as the expression | |
| 521 | + * | |
| 522 | + * <blockquote><pre> | |
| 523 | + * Channels.newReader(ch, | |
| 524 | + * Charset.forName(csName) | |
| 525 | + * .newDecoder(), | |
| 526 | + * -1);</pre></blockquote> | |
| 527 | + * | |
| 528 | + * @param ch | |
| 529 | + * The channel from which bytes will be read | |
| 530 | + * | |
| 531 | + * @param csName | |
| 532 | + * The name of the charset to be used | |
| 533 | + * | |
| 534 | + * @return A new reader | |
| 535 | + * | |
| 536 | + * @throws UnsupportedCharsetException | |
| 537 | + * If no support for the named charset is available | |
| 538 | + * in this instance of the Java virtual machine | |
| 539 | + */ | |
| 540 | + public static Reader newReader(ReadableByteChannel ch, | |
| 541 | + String csName) | |
| 542 | + { | |
| 543 | + checkNotNull(csName, "csName"); | |
| 544 | + return newReader(ch, Charset.forName(csName).newDecoder(), -1); | |
| 545 | + } | |
| 546 | + | |
| 547 | + /** | |
| 548 | + * Constructs a writer that encodes characters using the given encoder and | |
| 549 | + * writes the resulting bytes to the given channel. | |
| 550 | + * | |
| 551 | + * <p> The resulting stream will contain an internal output buffer of at | |
| 552 | + * least <tt>minBufferCap</tt> bytes. The stream's <tt>write</tt> methods | |
| 553 | + * will, as needed, flush the buffer by writing bytes to the underlying | |
| 554 | + * channel; if the channel is in non-blocking mode when bytes are to be | |
| 555 | + * written then an {@link IllegalBlockingModeException} will be thrown. | |
| 556 | + * The resulting stream will not otherwise be buffered. Closing the stream | |
| 557 | + * will in turn cause the channel to be closed. </p> | |
| 558 | + * | |
| 559 | + * @param ch | |
| 560 | + * The channel to which bytes will be written | |
| 561 | + * | |
| 562 | + * @param enc | |
| 563 | + * The charset encoder to be used | |
| 564 | + * | |
| 565 | + * @param minBufferCap | |
| 566 | + * The minimum capacity of the internal byte buffer, | |
| 567 | + * or <tt>-1</tt> if an implementation-dependent | |
| 568 | + * default capacity is to be used | |
| 569 | + * | |
| 570 | + * @return A new writer | |
| 571 | + */ | |
| 572 | + public static Writer newWriter(final WritableByteChannel ch, | |
| 573 | + final CharsetEncoder enc, | |
| 574 | + final int minBufferCap) | |
| 575 | + { | |
| 576 | + checkNotNull(ch, "ch"); | |
| 577 | + return StreamEncoder.forEncoder(ch, enc.reset(), minBufferCap); | |
| 578 | + } | |
| 579 | + | |
| 580 | + /** | |
| 581 | + * Constructs a writer that encodes characters according to the named | |
| 582 | + * charset and writes the resulting bytes to the given channel. | |
| 583 | + * | |
| 584 | + * <p> An invocation of this method of the form | |
| 585 | + * | |
| 586 | + * <blockquote><pre> | |
| 587 | + * Channels.newWriter(ch, csname)</pre></blockquote> | |
| 588 | + * | |
| 589 | + * behaves in exactly the same way as the expression | |
| 590 | + * | |
| 591 | + * <blockquote><pre> | |
| 592 | + * Channels.newWriter(ch, | |
| 593 | + * Charset.forName(csName) | |
| 594 | + * .newEncoder(), | |
| 595 | + * -1);</pre></blockquote> | |
| 596 | + * | |
| 597 | + * @param ch | |
| 598 | + * The channel to which bytes will be written | |
| 599 | + * | |
| 600 | + * @param csName | |
| 601 | + * The name of the charset to be used | |
| 602 | + * | |
| 603 | + * @return A new writer | |
| 604 | + * | |
| 605 | + * @throws UnsupportedCharsetException | |
| 606 | + * If no support for the named charset is available | |
| 607 | + * in this instance of the Java virtual machine | |
| 608 | + */ | |
| 609 | + public static Writer newWriter(WritableByteChannel ch, | |
| 610 | + String csName) | |
| 611 | + { | |
| 612 | + checkNotNull(csName, "csName"); | |
| 613 | + return newWriter(ch, Charset.forName(csName).newEncoder(), -1); | |
| 614 | + } | |
| 615 | +} | |