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