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 * @param buf A byte array
583 */
584 public void write(byte buf[]) {
585 try {
586 synchronized (this) {
587 ensureOpen();
588 out.write(buf);
589 if (autoFlush)
590 out.flush();
591 }
592 }
593 catch (InterruptedIOException x) {
594 Thread.currentThread().interrupt();
595 }
596 catch (IOException x) {
597 trouble = true;
598 }
599 }
600
601 /*
602 * The following private methods on the text- and character-output streams
603 * always flush the stream buffers, so that writes to the underlying byte
604 * stream occur as promptly as with the original PrintStream.
605 */
606
607 private void write(char[] buf) {
608 try {
609 synchronized (this) {
610 ensureOpen();
611 textOut.write(buf);
612 textOut.flushBuffer();
613 charOut.flushBuffer();
614 if (autoFlush) {
615 for (int i = 0; i < buf.length; i++)
616 if (buf[i] == '\n') {
617 out.flush();
618 break;
619 }
620 }
621 }
622 } catch (InterruptedIOException x) {
623 Thread.currentThread().interrupt();
624 } catch (IOException x) {
625 trouble = true;
626 }
627 }
628
629 // Used to optimize away back-to-back flushing and synchronization when
630 // using println, but since subclasses could exist which depend on
631 // observing a call to print followed by newLine() we only use this if
632 // getClass() == PrintStream.class to avoid compatibility issues.
633 private void writeln(char[] buf) {
634 try {
635 synchronized (this) {
636 ensureOpen();
637 textOut.write(buf);
638 textOut.newLine();
639 textOut.flushBuffer();
640 charOut.flushBuffer();
641 if (autoFlush)
642 out.flush();
643 }
644 }
645 catch (InterruptedIOException x) {
646 Thread.currentThread().interrupt();
647 }
648 catch (IOException x) {
649 trouble = true;
650 }
651 }
652
653 private void write(String s) {
654 try {
655 synchronized (this) {
656 ensureOpen();
657 textOut.write(s);
658 textOut.flushBuffer();
659 charOut.flushBuffer();
660 if (autoFlush && (s.indexOf('\n') >= 0))
661 out.flush();
662 }
663 }
664 catch (InterruptedIOException x) {
665 Thread.currentThread().interrupt();
666 }
667 catch (IOException x) {
668 trouble = true;
669 }
670 }
671
672 // Used to optimize away back-to-back flushing and synchronization when
673 // using println, but since subclasses could exist which depend on
674 // observing a call to print followed by newLine we only use this if
675 // getClass() == PrintStream.class to avoid compatibility issues.
676 private void writeln(String s) {
677 try {
678 synchronized (this) {
679 ensureOpen();
680 textOut.write(s);
681 textOut.newLine();
682 textOut.flushBuffer();
683 charOut.flushBuffer();
684 if (autoFlush)
685 out.flush();
686 }
687 }
688 catch (InterruptedIOException x) {
689 Thread.currentThread().interrupt();
690 }
691 catch (IOException x) {
692 trouble = true;
693 }
694 }
695
696 private void newLine() {
697 try {
698 synchronized (this) {
699 ensureOpen();
700 textOut.newLine();
701 textOut.flushBuffer();
702 charOut.flushBuffer();
703 if (autoFlush)
704 out.flush();
705 }
706 }
707 catch (InterruptedIOException x) {
708 Thread.currentThread().interrupt();
709 }
710 catch (IOException x) {
711 trouble = true;
712 }
713 }
714
715 /* Methods that do not terminate lines */
716
717 /**
718 * Prints a boolean value. The string produced by {@link
719 * java.lang.String#valueOf(boolean)} is translated into bytes
720 * according to the platform's default character encoding, and these bytes
721 * are written in exactly the manner of the
722 * {@link #write(int)} method.
723 *
724 * @param b The {@code boolean} to be printed
725 */
726 public void print(boolean b) {
727 write(String.valueOf(b));
728 }
729
730 /**
731 * Prints a character. The character is translated into one or more bytes
732 * according to the platform's default character encoding, and these bytes
733 * are written in exactly the manner of the
734 * {@link #write(int)} method.
735 *
736 * @param c The {@code char} to be printed
737 */
738 public void print(char c) {
739 write(String.valueOf(c));
740 }
741
742 /**
743 * Prints an integer. The string produced by {@link
744 * java.lang.String#valueOf(int)} is translated into bytes
745 * according to the platform's default character encoding, and these bytes
746 * are written in exactly the manner of the
747 * {@link #write(int)} method.
748 *
749 * @param i The {@code int} to be printed
750 * @see java.lang.Integer#toString(int)
751 */
752 public void print(int i) {
753 write(String.valueOf(i));
754 }
755
756 /**
757 * Prints a long integer. The string produced by {@link
758 * java.lang.String#valueOf(long)} is translated into bytes
759 * according to the platform's default character encoding, and these bytes
760 * are written in exactly the manner of the
761 * {@link #write(int)} method.
762 *
763 * @param l The {@code long} to be printed
764 * @see java.lang.Long#toString(long)
765 */
766 public void print(long l) {
767 write(String.valueOf(l));
768 }
769
770 /**
771 * Prints a floating-point number. The string produced by {@link
772 * java.lang.String#valueOf(float)} is translated into bytes
773 * according to the platform's default character encoding, and these bytes
774 * are written in exactly the manner of the
775 * {@link #write(int)} method.
776 *
777 * @param f The {@code float} to be printed
778 * @see java.lang.Float#toString(float)
779 */
780 public void print(float f) {
781 write(String.valueOf(f));
782 }
783
784 /**
785 * Prints a double-precision floating-point number. The string produced by
786 * {@link java.lang.String#valueOf(double)} is translated into
787 * bytes according to the platform's default character encoding, and these
788 * bytes are written in exactly the manner of the {@link
789 * #write(int)} method.
790 *
791 * @param d The {@code double} to be printed
792 * @see java.lang.Double#toString(double)
793 */
794 public void print(double d) {
795 write(String.valueOf(d));
796 }
797
798 /**
799 * Prints an array of characters. The characters are converted into bytes
800 * according to the platform's default character encoding, and these bytes
801 * are written in exactly the manner of the
802 * {@link #write(int)} method.
803 *
804 * @param s The array of chars to be printed
805 *
806 * @throws NullPointerException If {@code s} is {@code null}
807 */
808 public void print(char s[]) {
809 write(s);
810 }
811
812 /**
813 * Prints a string. If the argument is {@code null} then the string
814 * {@code "null"} is printed. Otherwise, the string's characters are
815 * converted into bytes according to the platform's default character
816 * encoding, and these bytes are written in exactly the manner of the
817 * {@link #write(int)} method.
818 *
819 * @param s The {@code String} to be printed
820 */
821 public void print(String s) {
822 write(String.valueOf(s));
823 }
824
825 /**
826 * Prints an object. The string produced by the {@link
827 * java.lang.String#valueOf(Object)} method is translated into bytes
828 * according to the platform's default character encoding, and these bytes
829 * are written in exactly the manner of the
830 * {@link #write(int)} method.
831 *
832 * @param obj The {@code Object} to be printed
833 * @see java.lang.Object#toString()
834 */
835 public void print(Object obj) {
836 write(String.valueOf(obj));
837 }
838
839
840 /* Methods that do terminate lines */
841
842 /**
843 * Terminates the current line by writing the line separator string. The
844 * line separator string is defined by the system property
845 * {@code line.separator}, and is not necessarily a single newline
846 * character ({@code '\n'}).
847 */
848 public void println() {
849 newLine();
850 }
851
852 /**
853 * Prints a boolean and then terminate the line. This method behaves as
854 * though it invokes {@link #print(boolean)} and then
855 * {@link #println()}.
856 *
857 * @param x The {@code boolean} to be printed
858 */
859 public void println(boolean x) {
860 if (getClass() == PrintStream.class) {
861 writeln(String.valueOf(x));
862 } else {
863 synchronized (this) {
864 print(x);
865 newLine();
866 }
867 }
868 }
869
870 /**
871 * Prints a character and then terminate the line. This method behaves as
872 * though it invokes {@link #print(char)} and then
873 * {@link #println()}.
874 *
875 * @param x The {@code char} to be printed.
876 */
877 public void println(char x) {
878 if (getClass() == PrintStream.class) {
879 writeln(String.valueOf(x));
880 } else {
881 synchronized (this) {
882 print(x);
883 newLine();
884 }
885 }
886 }
887
888 /**
889 * Prints an integer and then terminate the line. This method behaves as
890 * though it invokes {@link #print(int)} and then
891 * {@link #println()}.
892 *
893 * @param x The {@code int} to be printed.
894 */
895 public void println(int 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 long and then terminate the line. This method behaves as
908 * though it invokes {@link #print(long)} and then
909 * {@link #println()}.
910 *
911 * @param x a The {@code long} to be printed.
912 */
913 public void println(long 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 a float and then terminate the line. This method behaves as
926 * though it invokes {@link #print(float)} and then
927 * {@link #println()}.
928 *
929 * @param x The {@code float} to be printed.
930 */
931 public void println(float 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 double and then terminate the line. This method behaves as
944 * though it invokes {@link #print(double)} and then
945 * {@link #println()}.
946 *
947 * @param x The {@code double} to be printed.
948 */
949 public void println(double 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 an array of characters and then terminate the line. This method
962 * behaves as though it invokes {@link #print(char[])} and
963 * then {@link #println()}.
964 *
965 * @param x an array of chars to print.
966 */
967 public void println(char[] x) {
968 if (getClass() == PrintStream.class) {
969 writeln(x);
970 } else {
971 synchronized (this) {
972 print(x);
973 newLine();
974 }
975 }
976 }
977
978 /**
979 * Prints a String and then terminate the line. This method behaves as
980 * though it invokes {@link #print(String)} and then
981 * {@link #println()}.
982 *
983 * @param x The {@code String} to be printed.
984 */
985 public void println(String 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 Object and then terminate the line. This method calls
998 * at first String.valueOf(x) to get the printed object's string value,
999 * then behaves as
1000 * though it invokes {@link #print(String)} and then
1001 * {@link #println()}.
1002 *
1003 * @param x The {@code Object} to be printed.
1004 */
1005 public void println(Object x) {
1006 String s = String.valueOf(x);
1007 if (getClass() == PrintStream.class) {
1008 // need to apply String.valueOf again since first invocation
1009 // might return null
1010 writeln(String.valueOf(s));
1011 } else {
1012 synchronized (this) {
1013 print(s);
1014 newLine();
1015 }
1016 }
1017 }
1018
1019
1020 /**
1021 * A convenience method to write a formatted string to this output stream
1022 * using the specified format string and arguments.
1023 *
1024 * <p> An invocation of this method of the form
1025 * {@code out.printf(format, args)} behaves
1026 * in exactly the same way as the invocation
1027 *
1028 * <pre>{@code
1029 * out.format(format, args)
1030 * }</pre>
1031 *
1032 * @param format
1033 * A format string as described in <a
1034 * href="../util/Formatter.html#syntax">Format string syntax</a>
1035 *
1036 * @param args
1037 * Arguments referenced by the format specifiers in the format
1038 * string. If there are more arguments than format specifiers, the
1039 * extra arguments are ignored. The number of arguments is
1040 * variable and may be zero. The maximum number of arguments is
1041 * limited by the maximum dimension of a Java array as defined by
1042 * <cite>The Java™ Virtual Machine Specification</cite>.
1043 * The behaviour on a
1044 * {@code null} argument depends on the <a
1045 * href="../util/Formatter.html#syntax">conversion</a>.
1046 *
1047 * @throws java.util.IllegalFormatException
1048 * If a format string contains an illegal syntax, a format
1049 * specifier that is incompatible with the given arguments,
1050 * insufficient arguments given the format string, or other
1051 * illegal conditions. For specification of all possible
1052 * formatting errors, see the <a
1053 * href="../util/Formatter.html#detail">Details</a> section of the
1054 * formatter class specification.
1055 *
1056 * @throws NullPointerException
1057 * If the {@code format} is {@code null}
1058 *
1059 * @return This output stream
1060 *
1061 * @since 1.5
1062 */
1063 public PrintStream printf(String format, Object ... args) {
1064 return format(format, args);
1065 }
1066
1067 /**
1068 * A convenience method to write a formatted string to this output stream
1069 * using the specified format string and arguments.
1070 *
1071 * <p> An invocation of this method of the form
1072 * {@code out.printf(l, format, args)} behaves
1073 * in exactly the same way as the invocation
1074 *
1075 * <pre>{@code
1076 * out.format(l, format, args)
1077 * }</pre>
1078 *
1079 * @param l
1080 * The {@linkplain java.util.Locale locale} to apply during
1081 * formatting. If {@code l} is {@code null} then no localization
1082 * is applied.
1083 *
1084 * @param format
1085 * A format string as described in <a
1086 * href="../util/Formatter.html#syntax">Format string syntax</a>
1087 *
1088 * @param args
1089 * Arguments referenced by the format specifiers in the format
1090 * string. If there are more arguments than format specifiers, the
1091 * extra arguments are ignored. The number of arguments is
1092 * variable and may be zero. The maximum number of arguments is
1093 * limited by the maximum dimension of a Java array as defined by
1094 * <cite>The Java™ Virtual Machine Specification</cite>.
1095 * The behaviour on a
1096 * {@code null} argument depends on the <a
1097 * href="../util/Formatter.html#syntax">conversion</a>.
1098 *
1099 * @throws java.util.IllegalFormatException
1100 * If a format string contains an illegal syntax, a format
1101 * specifier that is incompatible with the given arguments,
1102 * insufficient arguments given the format string, or other
1103 * illegal conditions. For specification of all possible
1104 * formatting errors, see the <a
1105 * href="../util/Formatter.html#detail">Details</a> section of the
1106 * formatter class specification.
1107 *
1108 * @throws NullPointerException
1109 * If the {@code format} is {@code null}
1110 *
1111 * @return This output stream
1112 *
1113 * @since 1.5
1114 */
1115 public PrintStream printf(Locale l, String format, Object ... args) {
1116 return format(l, format, args);
1117 }
1118
1119 /**
1120 * Writes a formatted string to this output stream using the specified
1121 * format string and arguments.
1122 *
1123 * <p> The locale always used is the one returned by {@link
1124 * java.util.Locale#getDefault(Locale.Category)} with
1125 * {@link java.util.Locale.Category#FORMAT FORMAT} category specified,
1126 * regardless of any previous invocations of other formatting methods on
1127 * this object.
1128 *
1129 * @param format
1130 * A format string as described in <a
1131 * href="../util/Formatter.html#syntax">Format string syntax</a>
1132 *
1133 * @param args
1134 * Arguments referenced by the format specifiers in the format
1135 * string. If there are more arguments than format specifiers, the
1136 * extra arguments are ignored. The number of arguments is
1137 * variable and may be zero. The maximum number of arguments is
1138 * limited by the maximum dimension of a Java array as defined by
1139 * <cite>The Java™ Virtual Machine Specification</cite>.
1140 * The behaviour on a
1141 * {@code null} argument depends on the <a
1142 * href="../util/Formatter.html#syntax">conversion</a>.
1143 *
1144 * @throws java.util.IllegalFormatException
1145 * If a format string contains an illegal syntax, a format
1146 * specifier that is incompatible with the given arguments,
1147 * insufficient arguments given the format string, or other
1148 * illegal conditions. For specification of all possible
1149 * formatting errors, see the <a
1150 * href="../util/Formatter.html#detail">Details</a> section of the
1151 * formatter class specification.
1152 *
1153 * @throws NullPointerException
1154 * If the {@code format} is {@code null}
1155 *
1156 * @return This output stream
1157 *
1158 * @since 1.5
1159 */
1160 public PrintStream format(String format, Object ... args) {
1161 try {
1162 synchronized (this) {
1163 ensureOpen();
1164 if ((formatter == null)
1165 || (formatter.locale() !=
1166 Locale.getDefault(Locale.Category.FORMAT)))
1167 formatter = new Formatter((Appendable) this);
1168 formatter.format(Locale.getDefault(Locale.Category.FORMAT),
1169 format, args);
1170 }
1171 } catch (InterruptedIOException x) {
1172 Thread.currentThread().interrupt();
1173 } catch (IOException x) {
1174 trouble = true;
1175 }
1176 return this;
1177 }
1178
1179 /**
1180 * Writes a formatted string to this output stream using the specified
1181 * format string and arguments.
1182 *
1183 * @param l
1184 * The {@linkplain java.util.Locale locale} to apply during
1185 * formatting. If {@code l} is {@code null} then no localization
1186 * is applied.
1187 *
1188 * @param format
1189 * A format string as described in <a
1190 * href="../util/Formatter.html#syntax">Format string syntax</a>
1191 *
1192 * @param args
1193 * Arguments referenced by the format specifiers in the format
1194 * string. If there are more arguments than format specifiers, the
1195 * extra arguments are ignored. The number of arguments is
1196 * variable and may be zero. The maximum number of arguments is
1197 * limited by the maximum dimension of a Java array as defined by
1198 * <cite>The Java™ Virtual Machine Specification</cite>.
1199 * The behaviour on a
1200 * {@code null} argument depends on the <a
1201 * href="../util/Formatter.html#syntax">conversion</a>.
1202 *
1203 * @throws java.util.IllegalFormatException
1204 * If a format string contains an illegal syntax, a format
1205 * specifier that is incompatible with the given arguments,
1206 * insufficient arguments given the format string, or other
1207 * illegal conditions. For specification of all possible
1208 * formatting errors, see the <a
1209 * href="../util/Formatter.html#detail">Details</a> section of the
1210 * formatter class specification.
1211 *
1212 * @throws NullPointerException
1213 * If the {@code format} is {@code null}
1214 *
1215 * @return This output stream
1216 *
1217 * @since 1.5
1218 */
1219 public PrintStream format(Locale l, String format, Object ... args) {
1220 try {
1221 synchronized (this) {
1222 ensureOpen();
1223 if ((formatter == null)
1224 || (formatter.locale() != l))
1225 formatter = new Formatter(this, l);
1226 formatter.format(l, format, args);
1227 }
1228 } catch (InterruptedIOException x) {
1229 Thread.currentThread().interrupt();
1230 } catch (IOException x) {
1231 trouble = true;
1232 }
1233 return this;
1234 }
1235
1236 /**
1237 * Appends the specified character sequence to this output stream.
1238 *
1239 * <p> An invocation of this method of the form {@code out.append(csq)}
1240 * behaves in exactly the same way as the invocation
1241 *
1242 * <pre>{@code
1243 * out.print(csq.toString())
1244 * }</pre>
1245 *
1246 * <p> Depending on the specification of {@code toString} for the
1247 * character sequence {@code csq}, the entire sequence may not be
1248 * appended. For instance, invoking then {@code toString} method of a
1249 * character buffer will return a subsequence whose content depends upon
1250 * the buffer's position and limit.
1251 *
1252 * @param csq
1253 * The character sequence to append. If {@code csq} is
1254 * {@code null}, then the four characters {@code "null"} are
1255 * appended to this output stream.
1256 *
1257 * @return This output stream
1258 *
1259 * @since 1.5
1260 */
1261 public PrintStream append(CharSequence csq) {
1262 print(String.valueOf(csq));
1263 return this;
1264 }
1265
1266 /**
1267 * Appends a subsequence of the specified character sequence to this output
1268 * stream.
1269 *
1270 * <p> An invocation of this method of the form
1271 * {@code out.append(csq, start, end)} when
1272 * {@code csq} is not {@code null}, behaves in
1273 * exactly the same way as the invocation
1274 *
1275 * <pre>{@code
1276 * out.print(csq.subSequence(start, end).toString())
1277 * }</pre>
1278 *
1279 * @param csq
1280 * The character sequence from which a subsequence will be
1281 * appended. If {@code csq} is {@code null}, then characters
1282 * will be appended as if {@code csq} contained the four
1283 * characters {@code "null"}.
1284 *
1285 * @param start
1286 * The index of the first character in the subsequence
1287 *
1288 * @param end
1289 * The index of the character following the last character in the
1290 * subsequence
1291 *
1292 * @return This output stream
1293 *
1294 * @throws IndexOutOfBoundsException
1295 * If {@code start} or {@code end} are negative, {@code start}
1296 * is greater than {@code end}, or {@code end} is greater than
1297 * {@code csq.length()}
1298 *
1299 * @since 1.5
1300 */
1301 public PrintStream append(CharSequence csq, int start, int end) {
1302 if (csq == null) csq = "null";
1303 return append(csq.subSequence(start, end));
1304 }
1305
1306 /**
1307 * Appends the specified character to this output stream.
1308 *
1309 * <p> An invocation of this method of the form {@code out.append(c)}
1310 * behaves in exactly the same way as the invocation
1311 *
1312 * <pre>{@code
1313 * out.print(c)
1314 * }</pre>
1315 *
1316 * @param c
1317 * The 16-bit character to append
1318 *
1319 * @return This output stream
1320 *
1321 * @since 1.5
1322 */
1323 public PrintStream append(char c) {
1324 print(c);
1325 return this;
1326 }
1327
1328 }