001/* PrintStream.java -- OutputStream for printing output 002 Copyright (C) 1998, 1999, 2001, 2003, 2004, 2005, 2006 Free Software Foundation, Inc. 003 004This file is part of GNU Classpath. 005 006GNU Classpath is free software; you can redistribute it and/or modify 007it under the terms of the GNU General Public License as published by 008the Free Software Foundation; either version 2, or (at your option) 009any later version. 010 011GNU Classpath is distributed in the hope that it will be useful, but 012WITHOUT ANY WARRANTY; without even the implied warranty of 013MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 014General Public License for more details. 015 016You should have received a copy of the GNU General Public License 017along with GNU Classpath; see the file COPYING. If not, write to the 018Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 01902110-1301 USA. 020 021Linking this library statically or dynamically with other modules is 022making a combined work based on this library. Thus, the terms and 023conditions of the GNU General Public License cover the whole 024combination. 025 026As a special exception, the copyright holders of this library give you 027permission to link this library with independent modules to produce an 028executable, regardless of the license terms of these independent 029modules, and to copy and distribute the resulting executable under 030terms of your choice, provided that you also meet, for each linked 031independent module, the terms and conditions of the license of that 032module. An independent module is a module which is not derived from 033or based on this library. If you modify this library, you may extend 034this exception to your version of the library, but you are not 035obligated to do so. If you do not wish to do so, delete this 036exception statement from your version. */ 037 038 039package java.io; 040 041import java.util.Formatter; 042import java.util.Locale; 043 044import gnu.gcj.convert.UnicodeToBytes; 045 046/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3 047 * "The Java Language Specification", ISBN 0-201-63451-1 048 * Status: Believed complete and correct to 1.3 049 */ 050 051/** 052 * This class prints Java primitive values and object to a stream as 053 * text. None of the methods in this class throw an exception. However, 054 * errors can be detected by calling the <code>checkError()</code> method. 055 * Additionally, this stream can be designated as "autoflush" when 056 * created so that any writes are automatically flushed to the underlying 057 * output sink when the current line is terminated. 058 * <p> 059 * This class converts char's into byte's using the system default encoding. 060 * 061 * @author Aaron M. Renn (arenn@urbanophile.com) 062 * @author Tom Tromey (tromey@cygnus.com) 063 */ 064public class PrintStream extends FilterOutputStream implements Appendable 065{ 066 /* Notice the implementation is quite similar to OutputStreamWriter. 067 * This leads to some minor duplication, because neither inherits 068 * from the other, and we want to maximize performance. */ 069 070 // Line separator string. 071 private static final char[] line_separator 072 = System.getProperty("line.separator").toCharArray(); 073 074 UnicodeToBytes converter; 075 076 // Work buffer of characters for converter. 077 char[] work = new char[100]; 078 // Work buffer of bytes where we temporarily keep converter output. 079 byte[] work_bytes = new byte[100]; 080 081 /** 082 * This boolean indicates whether or not an error has ever occurred 083 * on this stream. 084 */ 085 private boolean error_occurred = false; 086 087 /** 088 * This is <code>true</code> if auto-flush is enabled, 089 * <code>false</code> otherwise 090 */ 091 private boolean auto_flush; 092 093 /** 094 * This method intializes a new <code>PrintStream</code> object to write 095 * to the specified output sink. 096 * 097 * @param out The <code>OutputStream</code> to write to. 098 */ 099 public PrintStream (OutputStream out) 100 { 101 this (out, false); 102 } 103 104 /** 105 * This method intializes a new <code>PrintStream</code> object to write 106 * to the specified output sink. This constructor also allows "auto-flush" 107 * functionality to be specified where the stream will be flushed after 108 * every <code>print</code> or <code>println</code> call, when the 109 * <code>write</code> methods with array arguments are called, or when a 110 * single new-line character is written. 111 * <p> 112 * 113 * @param out The <code>OutputStream</code> to write to. 114 * @param auto_flush <code>true</code> to flush the stream after every 115 * line, <code>false</code> otherwise 116 */ 117 public PrintStream (OutputStream out, boolean auto_flush) 118 { 119 super (out); 120 121 converter = UnicodeToBytes.getDefaultEncoder(); 122 this.auto_flush = auto_flush; 123 } 124 125 /** 126 * This method intializes a new <code>PrintStream</code> object to write 127 * to the specified output sink. This constructor also allows "auto-flush" 128 * functionality to be specified where the stream will be flushed after 129 * every <code>print</code> or <code>println</code> call, when the 130 * <code>write</code> methods with array arguments are called, or when a 131 * single new-line character is written. 132 * <p> 133 * 134 * @param out The <code>OutputStream</code> to write to. 135 * @param auto_flush <code>true</code> to flush the stream after every 136 * line, <code>false</code> otherwise 137 * @param encoding The name of the character encoding to use for this 138 * object. 139 */ 140 public PrintStream (OutputStream out, boolean auto_flush, String encoding) 141 throws UnsupportedEncodingException 142 { 143 super (out); 144 145 converter = UnicodeToBytes.getEncoder (encoding); 146 this.auto_flush = auto_flush; 147 } 148 149 /** 150 * This method checks to see if an error has occurred on this stream. Note 151 * that once an error has occurred, this method will continue to report 152 * <code>true</code> forever for this stream. Before checking for an 153 * error condition, this method flushes the stream. 154 * 155 * @return <code>true</code> if an error has occurred, 156 * <code>false</code> otherwise 157 */ 158 public boolean checkError () 159 { 160 flush (); 161 return error_occurred; 162 } 163 164 /** 165 * This method can be called by subclasses to indicate that an error 166 * has occurred and should be reported by <code>checkError</code>. 167 */ 168 protected void setError () 169 { 170 error_occurred = true; 171 } 172 173 /** 174 * This method closes this stream and all underlying streams. 175 */ 176 public void close () 177 { 178 try 179 { 180 converter.setFinished(); 181 writeChars(new char[0], 0, 0); 182 flush(); 183 out.close(); 184 } 185 catch (InterruptedIOException iioe) 186 { 187 Thread.currentThread().interrupt(); 188 } 189 catch (IOException e) 190 { 191 setError (); 192 } 193 } 194 195 /** 196 * This method flushes any buffered bytes to the underlying stream and 197 * then flushes that stream as well. 198 */ 199 public void flush () 200 { 201 try 202 { 203 out.flush(); 204 } 205 catch (InterruptedIOException iioe) 206 { 207 Thread.currentThread().interrupt(); 208 } 209 catch (IOException e) 210 { 211 setError (); 212 } 213 } 214 215 private synchronized void print (String str, boolean println) 216 { 217 try 218 { 219 writeChars(str, 0, str.length()); 220 if (println) 221 writeChars(line_separator, 0, line_separator.length); 222 if (auto_flush) 223 flush(); 224 } 225 catch (InterruptedIOException iioe) 226 { 227 Thread.currentThread().interrupt(); 228 } 229 catch (IOException e) 230 { 231 setError (); 232 } 233 } 234 235 private synchronized void print (char[] chars, int pos, int len, 236 boolean println) 237 { 238 try 239 { 240 writeChars(chars, pos, len); 241 if (println) 242 writeChars(line_separator, 0, line_separator.length); 243 if (auto_flush) 244 flush(); 245 } 246 catch (InterruptedIOException iioe) 247 { 248 Thread.currentThread().interrupt(); 249 } 250 catch (IOException e) 251 { 252 setError (); 253 } 254 } 255 256 private void writeChars(char[] buf, int offset, int count) 257 throws IOException 258 { 259 do 260 { 261 converter.setOutput(work_bytes, 0); 262 int converted = converter.write(buf, offset, count); 263 offset += converted; 264 count -= converted; 265 out.write(work_bytes, 0, converter.count); 266 } 267 while (count > 0 || converter.havePendingBytes()); 268 } 269 270 private void writeChars(String str, int offset, int count) 271 throws IOException 272 { 273 do 274 { 275 converter.setOutput(work_bytes, 0); 276 int converted = converter.write(str, offset, count, work); 277 offset += converted; 278 count -= converted; 279 out.write(work_bytes, 0, converter.count); 280 } 281 while (count > 0 || converter.havePendingBytes()); 282 } 283 284 /** 285 * This methods prints a boolean value to the stream. <code>true</code> 286 * values are printed as "true" and <code>false</code> values are printed 287 * as "false". 288 * 289 * @param bool The <code>boolean</code> value to print 290 */ 291 public void print (boolean bool) 292 { 293 print(String.valueOf(bool), false); 294 } 295 296 /** 297 * This method prints an integer to the stream. The value printed is 298 * determined using the <code>String.valueOf()</code> method. 299 * 300 * @param inum The <code>int</code> value to be printed 301 */ 302 public void print (int inum) 303 { 304 print(String.valueOf(inum), false); 305 } 306 307 /** 308 * This method prints a long to the stream. The value printed is 309 * determined using the <code>String.valueOf()</code> method. 310 * 311 * @param lnum The <code>long</code> value to be printed 312 */ 313 public void print (long lnum) 314 { 315 print(String.valueOf(lnum), false); 316 } 317 318 /** 319 * This method prints a float to the stream. The value printed is 320 * determined using the <code>String.valueOf()</code> method. 321 * 322 * @param fnum The <code>float</code> value to be printed 323 */ 324 public void print (float fnum) 325 { 326 print(String.valueOf(fnum), false); 327 } 328 329 /** 330 * This method prints a double to the stream. The value printed is 331 * determined using the <code>String.valueOf()</code> method. 332 * 333 * @param dnum The <code>double</code> value to be printed 334 */ 335 public void print (double dnum) 336 { 337 print(String.valueOf(dnum), false); 338 } 339 340 /** 341 * This method prints an <code>Object</code> to the stream. The actual 342 * value printed is determined by calling the <code>String.valueOf()</code> 343 * method. 344 * 345 * @param obj The <code>Object</code> to print. 346 */ 347 public void print (Object obj) 348 { 349 print(obj == null ? "null" : obj.toString(), false); 350 } 351 352 /** 353 * This method prints a <code>String</code> to the stream. The actual 354 * value printed depends on the system default encoding. 355 * 356 * @param str The <code>String</code> to print. 357 */ 358 public void print (String str) 359 { 360 print(str == null ? "null" : str, false); 361 } 362 363 /** 364 * This method prints a char to the stream. The actual value printed is 365 * determined by the character encoding in use. 366 * 367 * @param ch The <code>char</code> value to be printed 368 */ 369 public synchronized void print (char ch) 370 { 371 work[0] = ch; 372 print(work, 0, 1, false); 373 } 374 375 /** 376 * This method prints an array of characters to the stream. The actual 377 * value printed depends on the system default encoding. 378 * 379 * @param charArray The array of characters to print. 380 */ 381 public void print (char[] charArray) 382 { 383 print(charArray, 0, charArray.length, false); 384 } 385 386 /** 387 * This method prints a line separator sequence to the stream. The value 388 * printed is determined by the system property <xmp>line.separator</xmp> 389 * and is not necessarily the Unix '\n' newline character. 390 */ 391 public void println () 392 { 393 print(line_separator, 0, line_separator.length, false); 394 } 395 396 /** 397 * This methods prints a boolean value to the stream. <code>true</code> 398 * values are printed as "true" and <code>false</code> values are printed 399 * as "false". 400 * <p> 401 * This method prints a line termination sequence after printing the value. 402 * 403 * @param bool The <code>boolean</code> value to print 404 */ 405 public void println (boolean bool) 406 { 407 print(String.valueOf(bool), true); 408 } 409 410 /** 411 * This method prints an integer to the stream. The value printed is 412 * determined using the <code>String.valueOf()</code> method. 413 * <p> 414 * This method prints a line termination sequence after printing the value. 415 * 416 * @param inum The <code>int</code> value to be printed 417 */ 418 public void println (int inum) 419 { 420 print(String.valueOf(inum), true); 421 } 422 423 /** 424 * This method prints a long to the stream. The value printed is 425 * determined using the <code>String.valueOf()</code> method. 426 * <p> 427 * This method prints a line termination sequence after printing the value. 428 * 429 * @param lnum The <code>long</code> value to be printed 430 */ 431 public void println (long lnum) 432 { 433 print(String.valueOf(lnum), true); 434 } 435 436 /** 437 * This method prints a float to the stream. The value printed is 438 * determined using the <code>String.valueOf()</code> method. 439 * <p> 440 * This method prints a line termination sequence after printing the value. 441 * 442 * @param fnum The <code>float</code> value to be printed 443 */ 444 public void println (float fnum) 445 { 446 print(String.valueOf(fnum), true); 447 } 448 449 /** 450 * This method prints a double to the stream. The value printed is 451 * determined using the <code>String.valueOf()</code> method. 452 * <p> 453 * This method prints a line termination sequence after printing the value. 454 * 455 * @param dnum The <code>double</code> value to be printed 456 */ 457 public void println (double dnum) 458 { 459 print(String.valueOf(dnum), true); 460 } 461 462 /** 463 * This method prints an <code>Object</code> to the stream. The actual 464 * value printed is determined by calling the <code>String.valueOf()</code> 465 * method. 466 * <p> 467 * This method prints a line termination sequence after printing the value. 468 * 469 * @param obj The <code>Object</code> to print. 470 */ 471 public void println (Object obj) 472 { 473 print(obj == null ? "null" : obj.toString(), true); 474 } 475 476 /** 477 * This method prints a <code>String</code> to the stream. The actual 478 * value printed depends on the system default encoding. 479 * <p> 480 * This method prints a line termination sequence after printing the value. 481 * 482 * @param str The <code>String</code> to print. 483 */ 484 public void println (String str) 485 { 486 print (str == null ? "null" : str, true); 487 } 488 489 /** 490 * This method prints a char to the stream. The actual value printed is 491 * determined by the character encoding in use. 492 * <p> 493 * This method prints a line termination sequence after printing the value. 494 * 495 * @param ch The <code>char</code> value to be printed 496 */ 497 public synchronized void println (char ch) 498 { 499 work[0] = ch; 500 print(work, 0, 1, true); 501 } 502 503 /** 504 * This method prints an array of characters to the stream. The actual 505 * value printed depends on the system default encoding. 506 * <p> 507 * This method prints a line termination sequence after printing the value. 508 * 509 * @param charArray The array of characters to print. 510 */ 511 public void println (char[] charArray) 512 { 513 print(charArray, 0, charArray.length, true); 514 } 515 516 /** 517 * This method writes a byte of data to the stream. If auto-flush is 518 * enabled, printing a newline character will cause the stream to be 519 * flushed after the character is written. 520 * 521 * @param oneByte The byte to be written 522 */ 523 public void write (int oneByte) 524 { 525 try 526 { 527 out.write (oneByte & 0xff); 528 529 if (auto_flush && (oneByte == '\n')) 530 flush (); 531 } 532 catch (InterruptedIOException iioe) 533 { 534 Thread.currentThread ().interrupt (); 535 } 536 catch (IOException e) 537 { 538 setError (); 539 } 540 } 541 542 /** 543 * This method writes <code>len</code> bytes from the specified array 544 * starting at index <code>offset</code> into the array. 545 * 546 * @param buffer The array of bytes to write 547 * @param offset The index into the array to start writing from 548 * @param len The number of bytes to write 549 */ 550 public void write (byte[] buffer, int offset, int len) 551 { 552 try 553 { 554 out.write (buffer, offset, len); 555 556 if (auto_flush) 557 flush (); 558 } 559 catch (InterruptedIOException iioe) 560 { 561 Thread.currentThread ().interrupt (); 562 } 563 catch (IOException e) 564 { 565 setError (); 566 } 567 } 568 569 /** @since 1.5 */ 570 public PrintStream append(char c) 571 { 572 print(c); 573 return this; 574 } 575 576 /** @since 1.5 */ 577 public PrintStream append(CharSequence cs) 578 { 579 print(cs == null ? "null" : cs.toString()); 580 return this; 581 } 582 583 /** @since 1.5 */ 584 public PrintStream append(CharSequence cs, int start, int end) 585 { 586 print(cs == null ? "null" : cs.subSequence(start, end).toString()); 587 return this; 588 } 589 590 /** @since 1.5 */ 591 public PrintStream printf(String format, Object... args) 592 { 593 return format(format, args); 594 } 595 596 /** @since 1.5 */ 597 public PrintStream printf(Locale locale, String format, Object... args) 598 { 599 return format(locale, format, args); 600 } 601 602 /** @since 1.5 */ 603 public PrintStream format(String format, Object... args) 604 { 605 return format(Locale.getDefault(), format, args); 606 } 607 608 /** @since 1.5 */ 609 public PrintStream format(Locale locale, String format, Object... args) 610 { 611 Formatter f = new Formatter(this, locale); 612 f.format(format, args); 613 return this; 614 } 615} // class PrintStream 616