1 /*
2 * Copyright (c) 1996, 2019, 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.io;
27
28 import java.util.Formatter;
29 import java.util.Locale;
30 import java.nio.charset.Charset;
31 import java.nio.charset.IllegalCharsetNameException;
32 import java.nio.charset.UnsupportedCharsetException;
33
34 /**
35 * A {@code PrintStream} adds functionality to another output stream,
36 * namely the ability to print representations of various data values
37 * conveniently. Two other features are provided as well. Unlike other output
38 * streams, a {@code PrintStream} never throws an
39 * {@code IOException}; instead, exceptional situations merely set an
40 * internal flag that can be tested via the {@code checkError} method.
41 * Optionally, a {@code PrintStream} can be created so as to flush
42 * automatically; this means that the {@code flush} method is
43 * automatically invoked after a byte array is written, one of the
44 * {@code println} methods is invoked, or a newline character or byte
45 * ({@code '\n'}) is written.
46 *
47 * <p> All characters printed by a {@code PrintStream} are converted into
48 * bytes using the given encoding or charset, or the platform's default
49 * character encoding if not specified.
50 * The {@link PrintWriter} class should be used in situations that require
51 * writing characters rather than bytes.
52 *
53 * <p> This class always replaces malformed and unmappable character sequences with
54 * the charset's default replacement string.
55 * The {@linkplain java.nio.charset.CharsetEncoder} class should be used when more
56 * control over the encoding process is required.
57 *
58 * @author Frank Yellin
59 * @author Mark Reinhold
60 * @since 1.0
61 */
62
63 public class PrintStream extends FilterOutputStream
64 implements Appendable, Closeable
65 {
66
67 private final boolean autoFlush;
68 private boolean trouble = false;
69 private Formatter formatter;
70
71 /**
72 * Track both the text- and character-output streams, so that their buffers
73 * can be flushed without flushing the entire stream.
74 */
75 private BufferedWriter textOut;
76 private OutputStreamWriter charOut;
77
78 /**
79 * requireNonNull is explicitly declared here so as not to create an extra
80 * dependency on java.util.Objects.requireNonNull. PrintStream is loaded
81 * early during system initialization.
82 */
83 private static <T> T requireNonNull(T obj, String message) {
84 if (obj == null)
85 throw new NullPointerException(message);
86 return obj;
87 }
88
89 /**
90 * Returns a charset object for the given charset name.
91 * @throws NullPointerException is csn is null
92 * @throws UnsupportedEncodingException if the charset is not supported
93 */
94 private static Charset toCharset(String csn)
95 throws UnsupportedEncodingException
96 {
97 requireNonNull(csn, "charsetName");
98 try {
99 return Charset.forName(csn);
100 } catch (IllegalCharsetNameException|UnsupportedCharsetException unused) {
101 // UnsupportedEncodingException should be thrown
102 throw new UnsupportedEncodingException(csn);
103 }
104 }
105
106 /* Private constructors */
107 private PrintStream(boolean autoFlush, OutputStream out) {
108 super(out);
109 this.autoFlush = autoFlush;
110 this.charOut = new OutputStreamWriter(this);
111 this.textOut = new BufferedWriter(charOut);
112 }
113
114 /* Variant of the private constructor so that the given charset name
115 * can be verified before evaluating the OutputStream argument. Used
116 * by constructors creating a FileOutputStream that also take a
117 * charset name.
118 */
119 private PrintStream(boolean autoFlush, Charset charset, OutputStream out) {
120 this(out, autoFlush, charset);
121 }
122
123 /**
124 * Creates a new print stream, without automatic line flushing, with the
125 * specified OutputStream. Characters written to the stream are converted
126 * to bytes using the platform's default character encoding.
127 *
128 * @param out The output stream to which values and objects will be
129 * printed
130 *
131 * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream)
132 */
133 public PrintStream(OutputStream out) {
134 this(out, false);
135 }
136
137 /**
138 * Creates a new print stream, with the specified OutputStream and line
139 * flushing. Characters written to the stream are converted to bytes using
140 * the platform's default character encoding.
141 *
142 * @param out The output stream to which values and objects will be
143 * printed
144 * @param autoFlush Whether the output buffer will be flushed
145 * whenever a byte array is written, one of the
146 * {@code println} methods is invoked, or a newline
147 * character or byte ({@code '\n'}) is written
148 *
149 * @see java.io.PrintWriter#PrintWriter(java.io.OutputStream, boolean)
150 */
151 public PrintStream(OutputStream out, boolean autoFlush) {
152 this(autoFlush, requireNonNull(out, "Null output stream"));
153 }
154
155 /**
156 * Creates a new print stream, with the specified OutputStream, line
157 * flushing, and character encoding.
158 *
159 * @param out The output stream to which values and objects will be
160 * printed
161 * @param autoFlush Whether the output buffer will be flushed
162 * whenever a byte array is written, one of the
163 * {@code println} methods is invoked, or a newline
164 * character or byte ({@code '\n'}) is written
165 * @param encoding The name of a supported
166 * <a href="../lang/package-summary.html#charenc">
167 * character encoding</a>
168 *
169 * @throws UnsupportedEncodingException
170 * If the named encoding is not supported
171 *
172 * @since 1.4
173 */
174 public PrintStream(OutputStream out, boolean autoFlush, String encoding)
175 throws UnsupportedEncodingException
176 {
177 this(requireNonNull(out, "Null output stream"), autoFlush, toCharset(encoding));
178 }
179
180 /**
181 * Creates a new print stream, with the specified OutputStream, line
182 * flushing and charset. This convenience constructor creates the necessary
183 * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},
184 * which will encode characters using the provided charset.
185 *
186 * @param out The output stream to which values and objects will be
187 * printed
188 * @param autoFlush Whether the output buffer will be flushed
189 * whenever a byte array is written, one of the
190 * {@code println} methods is invoked, or a newline
191 * character or byte ({@code '\n'}) is written
192 * @param charset A {@linkplain java.nio.charset.Charset charset}
193 *
194 * @since 10
195 */
196 public PrintStream(OutputStream out, boolean autoFlush, Charset charset) {
197 super(out);
198 this.autoFlush = autoFlush;
199 this.charOut = new OutputStreamWriter(this, charset);
200 this.textOut = new BufferedWriter(charOut);
201 }
202
203 /**
204 * Creates a new print stream, without automatic line flushing, with the
205 * specified file name. This convenience constructor creates
206 * the necessary intermediate {@link java.io.OutputStreamWriter
207 * OutputStreamWriter}, which will encode characters using the
208 * {@linkplain java.nio.charset.Charset#defaultCharset() default charset}
209 * for this instance of the Java virtual machine.
210 *
211 * @param fileName
212 * The name of the file to use as the destination of this print
213 * stream. If the file exists, then it will be truncated to
214 * zero size; otherwise, a new file will be created. The output
215 * will be written to the file and is buffered.
216 *
217 * @throws FileNotFoundException
218 * If the given file object does not denote an existing, writable
219 * regular file and a new regular file of that name cannot be
220 * created, or if some other error occurs while opening or
221 * creating the file
222 *
223 * @throws SecurityException
224 * If a security manager is present and {@link
225 * SecurityManager#checkWrite checkWrite(fileName)} denies write
226 * access to the file
227 *
228 * @since 1.5
229 */
230 public PrintStream(String fileName) throws FileNotFoundException {
231 this(false, new FileOutputStream(fileName));
232 }
233
234 /**
235 * Creates a new print stream, without automatic line flushing, with the
236 * specified file name and charset. This convenience constructor creates
237 * the necessary intermediate {@link java.io.OutputStreamWriter
238 * OutputStreamWriter}, which will encode characters using the provided
239 * charset.
240 *
241 * @param fileName
242 * The name of the file to use as the destination of this print
243 * stream. If the file exists, then it will be truncated to
244 * zero size; otherwise, a new file will be created. The output
245 * will be written to the file and is buffered.
246 *
247 * @param csn
248 * The name of a supported {@linkplain java.nio.charset.Charset
249 * charset}
250 *
251 * @throws FileNotFoundException
252 * If the given file object does not denote an existing, writable
253 * regular file and a new regular file of that name cannot be
254 * created, or if some other error occurs while opening or
255 * creating the file
256 *
257 * @throws SecurityException
258 * If a security manager is present and {@link
259 * SecurityManager#checkWrite checkWrite(fileName)} denies write
260 * access to the file
261 *
262 * @throws UnsupportedEncodingException
263 * If the named charset is not supported
264 *
265 * @since 1.5
266 */
267 public PrintStream(String fileName, String csn)
268 throws FileNotFoundException, UnsupportedEncodingException
269 {
270 // ensure charset is checked before the file is opened
271 this(false, toCharset(csn), new FileOutputStream(fileName));
272 }
273
274 /**
275 * Creates a new print stream, without automatic line flushing, with the
276 * specified file name and charset. This convenience constructor creates
277 * the necessary intermediate {@link java.io.OutputStreamWriter
278 * OutputStreamWriter}, which will encode characters using the provided
279 * charset.
280 *
281 * @param fileName
282 * The name of the file to use as the destination of this print
283 * stream. If the file exists, then it will be truncated to
284 * zero size; otherwise, a new file will be created. The output
285 * will be written to the file and is buffered.
286 *
287 * @param charset
288 * A {@linkplain java.nio.charset.Charset charset}
289 *
290 * @throws IOException
291 * if an I/O error occurs while opening or creating the file
292 *
293 * @throws SecurityException
294 * If a security manager is present and {@link
295 * SecurityManager#checkWrite checkWrite(fileName)} denies write
296 * access to the file
297 *
298 * @since 10
299 */
300 public PrintStream(String fileName, Charset charset) throws IOException {
301 this(false, requireNonNull(charset, "charset"), new FileOutputStream(fileName));
302 }
303
304 /**
305 * Creates a new print stream, without automatic line flushing, with the
306 * specified file. This convenience constructor creates the necessary
307 * intermediate {@link java.io.OutputStreamWriter OutputStreamWriter},
308 * which will encode characters using the {@linkplain
309 * java.nio.charset.Charset#defaultCharset() default charset} for this
310 * instance of the Java virtual machine.
311 *
312 * @param file
313 * The file to use as the destination of this print stream. If the
314 * file exists, then it will be truncated to zero size; otherwise,
315 * a new file will be created. The output will be written to the
316 * file and is buffered.
317 *
318 * @throws FileNotFoundException
319 * If the given file object does not denote an existing, writable
320 * regular file and a new regular file of that name cannot be
321 * created, or if some other error occurs while opening or
322 * creating the file
323 *
324 * @throws SecurityException
325 * If a security manager is present and {@link
326 * SecurityManager#checkWrite checkWrite(file.getPath())}
327 * denies write access to the file
328 *
329 * @since 1.5
330 */
331 public PrintStream(File file) throws FileNotFoundException {
332 this(false, new FileOutputStream(file));
333 }
334
335 /**
336 * Creates a new print stream, without automatic line flushing, with the
337 * specified file and charset. This convenience constructor creates
338 * the necessary intermediate {@link java.io.OutputStreamWriter
339 * OutputStreamWriter}, which will encode characters using the provided
340 * charset.
341 *
342 * @param file
343 * The file to use as the destination of this print stream. If the
344 * file exists, then it will be truncated to zero size; otherwise,
345 * a new file will be created. The output will be written to the
346 * file and is buffered.
347 *
348 * @param csn
349 * The name of a supported {@linkplain java.nio.charset.Charset
350 * charset}
351 *
352 * @throws FileNotFoundException
353 * If the given file object does not denote an existing, writable
354 * regular file and a new regular file of that name cannot be
355 * created, or if some other error occurs while opening or
356 * creating the file
357 *
358 * @throws SecurityException
359 * If a security manager is present and {@link
360 * SecurityManager#checkWrite checkWrite(file.getPath())}
361 * denies write access to the file
362 *
363 * @throws UnsupportedEncodingException
364 * If the named charset is not supported
365 *
366 * @since 1.5
367 */
368 public PrintStream(File file, String csn)
369 throws FileNotFoundException, UnsupportedEncodingException
370 {
371 // ensure charset is checked before the file is opened
372 this(false, toCharset(csn), new FileOutputStream(file));
373 }
374
375
376 /**
377 * Creates a new print stream, without automatic line flushing, with the
378 * specified file and charset. This convenience constructor creates
379 * the necessary intermediate {@link java.io.OutputStreamWriter
380 * OutputStreamWriter}, which will encode characters using the provided
381 * charset.
382 *
383 * @param file
384 * The file to use as the destination of this print stream. If the
385 * file exists, then it will be truncated to zero size; otherwise,
386 * a new file will be created. The output will be written to the
387 * file and is buffered.
388 *
389 * @param charset
390 * A {@linkplain java.nio.charset.Charset charset}
391 *
392 * @throws IOException
393 * if an I/O error occurs while opening or creating the file
394 *
395 * @throws SecurityException
396 * If a security manager is present and {@link
397 * SecurityManager#checkWrite checkWrite(file.getPath())}
398 * denies write access to the file
399 *
400 * @since 10
401 */
402 public PrintStream(File file, Charset charset) throws IOException {
403 this(false, requireNonNull(charset, "charset"), new FileOutputStream(file));
404 }
405
406 /** Check to make sure that the stream has not been closed */
407 private void ensureOpen() throws IOException {
408 if (out == null)
409 throw new IOException("Stream closed");
410 }
411
412 /**
413 * Flushes the stream. This is done by writing any buffered output bytes to
414 * the underlying output stream and then flushing that stream.
415 *
416 * @see java.io.OutputStream#flush()
417 */
418 @Override
419 public void flush() {
420 synchronized (this) {
421 try {
422 ensureOpen();
423 out.flush();
424 }
425 catch (IOException x) {
426 trouble = true;
427 }
428 }
429 }
430
431 private boolean closing = false; /* To avoid recursive closing */
432
433 /**
434 * Closes the stream. This is done by flushing the stream and then closing
435 * the underlying output stream.
436 *
437 * @see java.io.OutputStream#close()
438 */
439 @Override
440 public void close() {
441 synchronized (this) {
442 if (! closing) {
443 closing = true;
444 try {
445 textOut.close();
446 out.close();
447 }
448 catch (IOException x) {
449 trouble = true;
450 }
451 textOut = null;
452 charOut = null;
453 out = null;
454 }
455 }
456 }
457
458 /**
459 * Flushes the stream and checks its error state. The internal error state
460 * is set to {@code true} when the underlying output stream throws an
461 * {@code IOException} other than {@code InterruptedIOException},
462 * and when the {@code setError} method is invoked. If an operation
463 * on the underlying output stream throws an
464 * {@code InterruptedIOException}, then the {@code PrintStream}
465 * converts the exception back into an interrupt by doing:
466 * <pre>{@code
467 * Thread.currentThread().interrupt();
468 * }</pre>
469 * or the equivalent.
470 *
471 * @return {@code true} if and only if this stream has encountered an
472 * {@code IOException} other than
473 * {@code InterruptedIOException}, or the
474 * {@code setError} method has been invoked
475 */
476 public boolean checkError() {
477 if (out != null)
478 flush();
479 if (out instanceof java.io.PrintStream) {
480 PrintStream ps = (PrintStream) out;
481 return ps.checkError();
482 }
483 return trouble;
484 }
485
486 /**
487 * Sets the error state of the stream to {@code true}.
488 *
489 * <p> This method will cause subsequent invocations of {@link
490 * #checkError()} to return {@code true} until
491 * {@link #clearError()} is invoked.
492 *
493 * @since 1.1
494 */
495 protected void setError() {
496 trouble = true;
497 }
498
499 /**
500 * Clears the internal error state of this stream.
501 *
502 * <p> This method will cause subsequent invocations of {@link
503 * #checkError()} to return {@code false} until another write
504 * operation fails and invokes {@link #setError()}.
505 *
506 * @since 1.6
507 */
508 protected void clearError() {
509 trouble = false;
510 }
511
512 /*
513 * Exception-catching, synchronized output operations,
514 * which also implement the write() methods of OutputStream
515 */
516
517 /**
518 * Writes the specified byte to this stream. If the byte is a newline and
519 * automatic flushing is enabled then the {@code flush} method will be
520 * invoked.
521 *
522 * <p> Note that the byte is written as given; to write a character that
523 * will be translated according to the platform's default character
524 * encoding, use the {@code print(char)} or {@code println(char)}
525 * methods.
526 *
527 * @param b The byte to be written
528 * @see #print(char)
529 * @see #println(char)
530 */
531 @Override
532 public void write(int b) {
533 try {
534 synchronized (this) {
535 ensureOpen();
536 out.write(b);
537 if ((b == '\n') && autoFlush)
538 out.flush();
539 }
540 }
541 catch (InterruptedIOException x) {
542 Thread.currentThread().interrupt();
543 }
544 catch (IOException x) {
545 trouble = true;
546 }
547 }
548
549 /**
550 * Writes {@code len} bytes from the specified byte array starting at
551 * offset {@code off} to this stream. If automatic flushing is
552 * enabled then the {@code flush} method will be invoked.
553 *
554 * <p> Note that the bytes will be written as given; to write characters
555 * that will be translated according to the platform's default character
556 * encoding, use the {@code print(char)} or {@code println(char)}
557 * methods.
558 *
559 * @param buf A byte array
560 * @param off Offset from which to start taking bytes
561 * @param len Number of bytes to write
562 */
563 @Override
564 public void write(byte buf[], int off, int len) {
565 try {
566 synchronized (this) {
567 ensureOpen();
568 out.write(buf, off, len);
569 if (autoFlush)
570 out.flush();
571 }
572 }
573 catch (InterruptedIOException x) {
574 Thread.currentThread().interrupt();
575 }
576 catch (IOException x) {
577 trouble = true;
578 }
579 }
580
581 /**
582 * Writes all bytes from the specified byte array to this stream.
583 * The automatic flushing setting is ignored. The internal flag
584 * tested by {@link #checkError()} will <i>not</i> be set if an
585 * {@code IOException} is thrown.
586 *
587 * <p> Note that the bytes will be written as given; to write characters
588 * that will be translated according to the platform's default character
589 * encoding, use the {@code print(char[])} or {@code println(char[])}
590 * methods.
591 *
592 * @apiNote
593 * Unlike other overridden methods in this class, this method may throw
594 * an {@code IOException}. To write an array of bytes without being
595 * required to handle an {@code IOException}, use either
596 * {@link #writeBytes(byte[] buf) writeBytes(buf)} or
597 * {@link #write(byte[],int,int) write(buf,0,buf.length)}.
598 *
599 * @implSpec
600 * The default implementation is equivalent to
601 * {@link java.io.FilterOutputStream#write(byte[],int,int)
602 * super.write(buf,0,buf.length)}.
603 *
604 * @param buf A byte array
605 *
606 * @see #writeBytes(byte[])
607 * @see #write(byte[],int,int)
608 */
609 @Override
610 public void write(byte buf[]) throws IOException {
611 super.write(buf, 0, buf.length);
612 }
613
614 /**
615 * Writes all bytes from the specified byte array to this stream.
616 * If automatic flushing is enabled then the {@code flush} method
617 * will be invoked.
618 *
619 * <p> Note that the bytes will be written as given; to write characters
620 * that will be translated according to the platform's default character
621 * encoding, use the {@code print(char[])} or {@code println(char[])}
622 * methods.
623 *
624 * @implSpec
625 * The default implementation is equivalent to
626 * {@link #write(byte[],int,int) this.write(buf, 0, buf.length)}.
627 *
628 * @param buf A byte array
629 *
630 * @since 14
631 */
632 public void writeBytes(byte buf[]) {
633 this.write(buf, 0, buf.length);
634 }
635
636 /*
637 * The following private methods on the text- and character-output streams
638 * always flush the stream buffers, so that writes to the underlying byte
639 * stream occur as promptly as with the original PrintStream.
640 */
641
642 private void write(char[] buf) {
643 try {
644 synchronized (this) {
645 ensureOpen();
646 textOut.write(buf);
647 textOut.flushBuffer();
648 charOut.flushBuffer();
649 if (autoFlush) {
650 for (int i = 0; i < buf.length; i++)
651 if (buf[i] == '\n') {
652 out.flush();
653 break;
654 }
655 }
656 }
657 } catch (InterruptedIOException x) {
658 Thread.currentThread().interrupt();
659 } catch (IOException x) {
660 trouble = true;
661 }
662 }
663
664 // Used to optimize away back-to-back flushing and synchronization when
665 // using println, but since subclasses could exist which depend on
666 // observing a call to print followed by newLine() we only use this if
667 // getClass() == PrintStream.class to avoid compatibility issues.
668 private void writeln(char[] buf) {
669 try {
670 synchronized (this) {
671 ensureOpen();
672 textOut.write(buf);
673 textOut.newLine();
674 textOut.flushBuffer();
675 charOut.flushBuffer();
676 if (autoFlush)
677 out.flush();
678 }
679 }
680 catch (InterruptedIOException x) {
681 Thread.currentThread().interrupt();
682 }
683 catch (IOException x) {
684 trouble = true;
685 }
686 }
687
688 private void write(String s) {
689 try {
690 synchronized (this) {
691 ensureOpen();
692 textOut.write(s);
693 textOut.flushBuffer();
694 charOut.flushBuffer();
695 if (autoFlush && (s.indexOf('\n') >= 0))
696 out.flush();
697 }
698 }
699 catch (InterruptedIOException x) {
700 Thread.currentThread().interrupt();
701 }
702 catch (IOException x) {
703 trouble = true;
704 }
705 }
706
707 // Used to optimize away back-to-back flushing and synchronization when
708 // using println, but since subclasses could exist which depend on
709 // observing a call to print followed by newLine we only use this if
710 // getClass() == PrintStream.class to avoid compatibility issues.
711 private void writeln(String s) {
712 try {
713 synchronized (this) {
714 ensureOpen();
715 textOut.write(s);
716 textOut.newLine();
717 textOut.flushBuffer();
718 charOut.flushBuffer();
719 if (autoFlush)
720 out.flush();
721 }
722 }
723 catch (InterruptedIOException x) {
724 Thread.currentThread().interrupt();
725 }
726 catch (IOException x) {
727 trouble = true;
728 }
729 }
730
731 private void newLine() {
732 try {
733 synchronized (this) {
734 ensureOpen();
735 textOut.newLine();
736 textOut.flushBuffer();
737 charOut.flushBuffer();
738 if (autoFlush)
739 out.flush();
740 }
741 }
742 catch (InterruptedIOException x) {
743 Thread.currentThread().interrupt();
744 }
745 catch (IOException x) {
746 trouble = true;
747 }
748 }
749
750 /* Methods that do not terminate lines */
751
752 /**
753 * Prints a boolean value. The string produced by {@link
754 * java.lang.String#valueOf(boolean)} is translated into bytes
755 * according to the platform's default character encoding, and these bytes
756 * are written in exactly the manner of the
757 * {@link #write(int)} method.
758 *
759 * @param b The {@code boolean} to be printed
760 */
761 public void print(boolean b) {
762 write(String.valueOf(b));
763 }
764
765 /**
766 * Prints a character. The character is translated into one or more bytes
767 * according to the character encoding given to the constructor, or the
768 * platform's default character encoding if none specified. These bytes
769 * are written in exactly the manner of the {@link #write(int)} method.
770 *
771 * @param c The {@code char} to be printed
772 */
773 public void print(char c) {
774 write(String.valueOf(c));
775 }
776
777 /**
778 * Prints an integer. The string produced by {@link
779 * java.lang.String#valueOf(int)} is translated into bytes
780 * according to the platform's default character encoding, and these bytes
781 * are written in exactly the manner of the
782 * {@link #write(int)} method.
783 *
784 * @param i The {@code int} to be printed
785 * @see java.lang.Integer#toString(int)
786 */
787 public void print(int i) {
788 write(String.valueOf(i));
789 }
790
791 /**
792 * Prints a long integer. The string produced by {@link
793 * java.lang.String#valueOf(long)} is translated into bytes
794 * according to the platform's default character encoding, and these bytes
795 * are written in exactly the manner of the
796 * {@link #write(int)} method.
797 *
798 * @param l The {@code long} to be printed
799 * @see java.lang.Long#toString(long)
800 */
801 public void print(long l) {
802 write(String.valueOf(l));
803 }
804
805 /**
806 * Prints a floating-point number. The string produced by {@link
807 * java.lang.String#valueOf(float)} is translated into bytes
808 * according to the platform's default character encoding, and these bytes
809 * are written in exactly the manner of the
810 * {@link #write(int)} method.
811 *
812 * @param f The {@code float} to be printed
813 * @see java.lang.Float#toString(float)
814 */
815 public void print(float f) {
816 write(String.valueOf(f));
817 }
818
819 /**
820 * Prints a double-precision floating-point number. The string produced by
821 * {@link java.lang.String#valueOf(double)} is translated into
822 * bytes according to the platform's default character encoding, and these
823 * bytes are written in exactly the manner of the {@link
824 * #write(int)} method.
825 *
826 * @param d The {@code double} to be printed
827 * @see java.lang.Double#toString(double)
828 */
829 public void print(double d) {
830 write(String.valueOf(d));
831 }
832
833 /**
834 * Prints an array of characters. The characters are converted into bytes
835 * according to the character encoding given to the constructor, or the
836 * platform's default character encoding if none specified. These bytes
837 * are written in exactly the manner of the {@link #write(int)} method.
838 *
839 * @param s The array of chars to be printed
840 *
841 * @throws NullPointerException If {@code s} is {@code null}
842 */
843 public void print(char s[]) {
844 write(s);
845 }
846
847 /**
848 * Prints a string. If the argument is {@code null} then the string
849 * {@code "null"} is printed. Otherwise, the string's characters are
850 * converted into bytes according to the character encoding given to the
851 * constructor, or the platform's default character encoding if none
852 * specified. These bytes are written in exactly the manner of the
853 * {@link #write(int)} method.
854 *
855 * @param s The {@code String} to be printed
856 */
857 public void print(String s) {
858 write(String.valueOf(s));
859 }
860
861 /**
862 * Prints an object. The string produced by the {@link
863 * java.lang.String#valueOf(Object)} method is translated into bytes
864 * according to the platform's default character encoding, and these bytes
865 * are written in exactly the manner of the
866 * {@link #write(int)} method.
867 *
868 * @param obj The {@code Object} to be printed
869 * @see java.lang.Object#toString()
870 */
871 public void print(Object obj) {
872 write(String.valueOf(obj));
873 }
874
875
876 /* Methods that do terminate lines */
877
878 /**
879 * Terminates the current line by writing the line separator string. The
880 * line separator string is defined by the system property
881 * {@code line.separator}, and is not necessarily a single newline
882 * character ({@code '\n'}).
883 */
884 public void println() {
885 newLine();
886 }
887
888 /**
889 * Prints a boolean and then terminate the line. This method behaves as
890 * though it invokes {@link #print(boolean)} and then
891 * {@link #println()}.
892 *
893 * @param x The {@code boolean} to be printed
894 */
895 public void println(boolean x) {
896 if (getClass() == PrintStream.class) {
897 writeln(String.valueOf(x));
898 } else {
899 synchronized (this) {
900 print(x);
901 newLine();
902 }
903 }
904 }
905
906 /**
907 * Prints a character and then terminate the line. This method behaves as
908 * though it invokes {@link #print(char)} and then
909 * {@link #println()}.
910 *
911 * @param x The {@code char} to be printed.
912 */
913 public void println(char x) {
914 if (getClass() == PrintStream.class) {
915 writeln(String.valueOf(x));
916 } else {
917 synchronized (this) {
918 print(x);
919 newLine();
920 }
921 }
922 }
923
924 /**
925 * Prints an integer and then terminate the line. This method behaves as
926 * though it invokes {@link #print(int)} and then
927 * {@link #println()}.
928 *
929 * @param x The {@code int} to be printed.
930 */
931 public void println(int x) {
932 if (getClass() == PrintStream.class) {
933 writeln(String.valueOf(x));
934 } else {
935 synchronized (this) {
936 print(x);
937 newLine();
938 }
939 }
940 }
941
942 /**
943 * Prints a long and then terminate the line. This method behaves as
944 * though it invokes {@link #print(long)} and then
945 * {@link #println()}.
946 *
947 * @param x a The {@code long} to be printed.
948 */
949 public void println(long x) {
950 if (getClass() == PrintStream.class) {
951 writeln(String.valueOf(x));
952 } else {
953 synchronized (this) {
954 print(x);
955 newLine();
956 }
957 }
958 }
959
960 /**
961 * Prints a float and then terminate the line. This method behaves as
962 * though it invokes {@link #print(float)} and then
963 * {@link #println()}.
964 *
965 * @param x The {@code float} to be printed.
966 */
967 public void println(float x) {
968 if (getClass() == PrintStream.class) {
969 writeln(String.valueOf(x));
970 } else {
971 synchronized (this) {
972 print(x);
973 newLine();
974 }
975 }
976 }
977
978 /**
979 * Prints a double and then terminate the line. This method behaves as
980 * though it invokes {@link #print(double)} and then
981 * {@link #println()}.
982 *
983 * @param x The {@code double} to be printed.
984 */
985 public void println(double x) {
986 if (getClass() == PrintStream.class) {
987 writeln(String.valueOf(x));
988 } else {
989 synchronized (this) {
990 print(x);
991 newLine();
992 }
993 }
994 }
995
996 /**
997 * Prints an array of characters and then terminate the line. This method
998 * behaves as though it invokes {@link #print(char[])} and
999 * then {@link #println()}.
1000 *
1001 * @param x an array of chars to print.
1002 */
1003 public void println(char[] x) {
1004 if (getClass() == PrintStream.class) {
1005 writeln(x);
1006 } else {
1007 synchronized (this) {
1008 print(x);
1009 newLine();
1010 }
1011 }
1012 }
1013
1014 /**
1015 * Prints a String and then terminate the line. This method behaves as
1016 * though it invokes {@link #print(String)} and then
1017 * {@link #println()}.
1018 *
1019 * @param x The {@code String} to be printed.
1020 */
1021 public void println(String x) {
1022 if (getClass() == PrintStream.class) {
1023 writeln(String.valueOf(x));
1024 } else {
1025 synchronized (this) {
1026 print(x);
1027 newLine();
1028 }
1029 }
1030 }
1031
1032 /**
1033 * Prints an Object and then terminate the line. This method calls
1034 * at first String.valueOf(x) to get the printed object's string value,
1035 * then behaves as
1036 * though it invokes {@link #print(String)} and then
1037 * {@link #println()}.
1038 *
1039 * @param x The {@code Object} to be printed.
1040 */
1041 public void println(Object x) {
1042 String s = String.valueOf(x);
1043 if (getClass() == PrintStream.class) {
1044 // need to apply String.valueOf again since first invocation
1045 // might return null
1046 writeln(String.valueOf(s));
1047 } else {
1048 synchronized (this) {
1049 print(s);
1050 newLine();
1051 }
1052 }
1053 }
1054
1055
1056 /**
1057 * A convenience method to write a formatted string to this output stream
1058 * using the specified format string and arguments.
1059 *
1060 * <p> An invocation of this method of the form
1061 * {@code out.printf(format, args)} behaves
1062 * in exactly the same way as the invocation
1063 *
1064 * <pre>{@code
1065 * out.format(format, args)
1066 * }</pre>
1067 *
1068 * @param format
1069 * A format string as described in <a
1070 * href="../util/Formatter.html#syntax">Format string syntax</a>
1071 *
1072 * @param args
1073 * Arguments referenced by the format specifiers in the format
1074 * string. If there are more arguments than format specifiers, the
1075 * extra arguments are ignored. The number of arguments is
1076 * variable and may be zero. The maximum number of arguments is
1077 * limited by the maximum dimension of a Java array as defined by
1078 * <cite>The Java™ Virtual Machine Specification</cite>.
1079 * The behaviour on a
1080 * {@code null} argument depends on the <a
1081 * href="../util/Formatter.html#syntax">conversion</a>.
1082 *
1083 * @throws java.util.IllegalFormatException
1084 * If a format string contains an illegal syntax, a format
1085 * specifier that is incompatible with the given arguments,
1086 * insufficient arguments given the format string, or other
1087 * illegal conditions. For specification of all possible
1088 * formatting errors, see the <a
1089 * href="../util/Formatter.html#detail">Details</a> section of the
1090 * formatter class specification.
1091 *
1092 * @throws NullPointerException
1093 * If the {@code format} is {@code null}
1094 *
1095 * @return This output stream
1096 *
1097 * @since 1.5
1098 */
1099 public PrintStream printf(String format, Object ... args) {
1100 return format(format, args);
1101 }
1102
1103 /**
1104 * A convenience method to write a formatted string to this output stream
1105 * using the specified format string and arguments.
1106 *
1107 * <p> An invocation of this method of the form
1108 * {@code out.printf(l, format, args)} behaves
1109 * in exactly the same way as the invocation
1110 *
1111 * <pre>{@code
1112 * out.format(l, format, args)
1113 * }</pre>
1114 *
1115 * @param l
1116 * The {@linkplain java.util.Locale locale} to apply during
1117 * formatting. If {@code l} is {@code null} then no localization
1118 * is applied.
1119 *
1120 * @param format
1121 * A format string as described in <a
1122 * href="../util/Formatter.html#syntax">Format string syntax</a>
1123 *
1124 * @param args
1125 * Arguments referenced by the format specifiers in the format
1126 * string. If there are more arguments than format specifiers, the
1127 * extra arguments are ignored. The number of arguments is
1128 * variable and may be zero. The maximum number of arguments is
1129 * limited by the maximum dimension of a Java array as defined by
1130 * <cite>The Java™ Virtual Machine Specification</cite>.
1131 * The behaviour on a
1132 * {@code null} argument depends on the <a
1133 * href="../util/Formatter.html#syntax">conversion</a>.
1134 *
1135 * @throws java.util.IllegalFormatException
1136 * If a format string contains an illegal syntax, a format
1137 * specifier that is incompatible with the given arguments,
1138 * insufficient arguments given the format string, or other
1139 * illegal conditions. For specification of all possible
1140 * formatting errors, see the <a
1141 * href="../util/Formatter.html#detail">Details</a> section of the
1142 * formatter class specification.
1143 *
1144 * @throws NullPointerException
1145 * If the {@code format} is {@code null}
1146 *
1147 * @return This output stream
1148 *
1149 * @since 1.5
1150 */
1151 public PrintStream printf(Locale l, String format, Object ... args) {
1152 return format(l, format, args);
1153 }
1154
1155 /**
1156 * Writes a formatted string to this output stream using the specified
1157 * format string and arguments.
1158 *
1159 * <p> The locale always used is the one returned by {@link
1160 * java.util.Locale#getDefault(Locale.Category)} with
1161 * {@link java.util.Locale.Category#FORMAT FORMAT} category specified,
1162 * regardless of any previous invocations of other formatting methods on
1163 * this object.
1164 *
1165 * @param format
1166 * A format string as described in <a
1167 * href="../util/Formatter.html#syntax">Format string syntax</a>
1168 *
1169 * @param args
1170 * Arguments referenced by the format specifiers in the format
1171 * string. If there are more arguments than format specifiers, the
1172 * extra arguments are ignored. The number of arguments is
1173 * variable and may be zero. The maximum number of arguments is
1174 * limited by the maximum dimension of a Java array as defined by
1175 * <cite>The Java™ Virtual Machine Specification</cite>.
1176 * The behaviour on a
1177 * {@code null} argument depends on the <a
1178 * href="../util/Formatter.html#syntax">conversion</a>.
1179 *
1180 * @throws java.util.IllegalFormatException
1181 * If a format string contains an illegal syntax, a format
1182 * specifier that is incompatible with the given arguments,
1183 * insufficient arguments given the format string, or other
1184 * illegal conditions. For specification of all possible
1185 * formatting errors, see the <a
1186 * href="../util/Formatter.html#detail">Details</a> section of the
1187 * formatter class specification.
1188 *
1189 * @throws NullPointerException
1190 * If the {@code format} is {@code null}
1191 *
1192 * @return This output stream
1193 *
1194 * @since 1.5
1195 */
1196 public PrintStream format(String format, Object ... args) {
1197 try {
1198 synchronized (this) {
1199 ensureOpen();
1200 if ((formatter == null)
1201 || (formatter.locale() !=
1202 Locale.getDefault(Locale.Category.FORMAT)))
1203 formatter = new Formatter((Appendable) this);
1204 formatter.format(Locale.getDefault(Locale.Category.FORMAT),
1205 format, args);
1206 }
1207 } catch (InterruptedIOException x) {
1208 Thread.currentThread().interrupt();
1209 } catch (IOException x) {
1210 trouble = true;
1211 }
1212 return this;
1213 }
1214
1215 /**
1216 * Writes a formatted string to this output stream using the specified
1217 * format string and arguments.
1218 *
1219 * @param l
1220 * The {@linkplain java.util.Locale locale} to apply during
1221 * formatting. If {@code l} is {@code null} then no localization
1222 * is applied.
1223 *
1224 * @param format
1225 * A format string as described in <a
1226 * href="../util/Formatter.html#syntax">Format string syntax</a>
1227 *
1228 * @param args
1229 * Arguments referenced by the format specifiers in the format
1230 * string. If there are more arguments than format specifiers, the
1231 * extra arguments are ignored. The number of arguments is
1232 * variable and may be zero. The maximum number of arguments is
1233 * limited by the maximum dimension of a Java array as defined by
1234 * <cite>The Java™ Virtual Machine Specification</cite>.
1235 * The behaviour on a
1236 * {@code null} argument depends on the <a
1237 * href="../util/Formatter.html#syntax">conversion</a>.
1238 *
1239 * @throws java.util.IllegalFormatException
1240 * If a format string contains an illegal syntax, a format
1241 * specifier that is incompatible with the given arguments,
1242 * insufficient arguments given the format string, or other
1243 * illegal conditions. For specification of all possible
1244 * formatting errors, see the <a
1245 * href="../util/Formatter.html#detail">Details</a> section of the
1246 * formatter class specification.
1247 *
1248 * @throws NullPointerException
1249 * If the {@code format} is {@code null}
1250 *
1251 * @return This output stream
1252 *
1253 * @since 1.5
1254 */
1255 public PrintStream format(Locale l, String format, Object ... args) {
1256 try {
1257 synchronized (this) {
1258 ensureOpen();
1259 if ((formatter == null)
1260 || (formatter.locale() != l))
1261 formatter = new Formatter(this, l);
1262 formatter.format(l, format, args);
1263 }
1264 } catch (InterruptedIOException x) {
1265 Thread.currentThread().interrupt();
1266 } catch (IOException x) {
1267 trouble = true;
1268 }
1269 return this;
1270 }
1271
1272 /**
1273 * Appends the specified character sequence to this output stream.
1274 *
1275 * <p> An invocation of this method of the form {@code out.append(csq)}
1276 * behaves in exactly the same way as the invocation
1277 *
1278 * <pre>{@code
1279 * out.print(csq.toString())
1280 * }</pre>
1281 *
1282 * <p> Depending on the specification of {@code toString} for the
1283 * character sequence {@code csq}, the entire sequence may not be
1284 * appended. For instance, invoking then {@code toString} method of a
1285 * character buffer will return a subsequence whose content depends upon
1286 * the buffer's position and limit.
1287 *
1288 * @param csq
1289 * The character sequence to append. If {@code csq} is
1290 * {@code null}, then the four characters {@code "null"} are
1291 * appended to this output stream.
1292 *
1293 * @return This output stream
1294 *
1295 * @since 1.5
1296 */
1297 public PrintStream append(CharSequence csq) {
1298 print(String.valueOf(csq));
1299 return this;
1300 }
1301
1302 /**
1303 * Appends a subsequence of the specified character sequence to this output
1304 * stream.
1305 *
1306 * <p> An invocation of this method of the form
1307 * {@code out.append(csq, start, end)} when
1308 * {@code csq} is not {@code null}, behaves in
1309 * exactly the same way as the invocation
1310 *
1311 * <pre>{@code
1312 * out.print(csq.subSequence(start, end).toString())
1313 * }</pre>
1314 *
1315 * @param csq
1316 * The character sequence from which a subsequence will be
1317 * appended. If {@code csq} is {@code null}, then characters
1318 * will be appended as if {@code csq} contained the four
1319 * characters {@code "null"}.
1320 *
1321 * @param start
1322 * The index of the first character in the subsequence
1323 *
1324 * @param end
1325 * The index of the character following the last character in the
1326 * subsequence
1327 *
1328 * @return This output stream
1329 *
1330 * @throws IndexOutOfBoundsException
1331 * If {@code start} or {@code end} are negative, {@code start}
1332 * is greater than {@code end}, or {@code end} is greater than
1333 * {@code csq.length()}
1334 *
1335 * @since 1.5
1336 */
1337 public PrintStream append(CharSequence csq, int start, int end) {
1338 if (csq == null) csq = "null";
1339 return append(csq.subSequence(start, end));
1340 }
1341
1342 /**
1343 * Appends the specified character to this output stream.
1344 *
1345 * <p> An invocation of this method of the form {@code out.append(c)}
1346 * behaves in exactly the same way as the invocation
1347 *
1348 * <pre>{@code
1349 * out.print(c)
1350 * }</pre>
1351 *
1352 * @param c
1353 * The 16-bit character to append
1354 *
1355 * @return This output stream
1356 *
1357 * @since 1.5
1358 */
1359 public PrintStream append(char c) {
1360 print(c);
1361 return this;
1362 }
1363
1364 }