1 /*
2 * Copyright (c) 1996, 2017, 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 * The following private methods on the text- and character-output streams
574 * always flush the stream buffers, so that writes to the underlying byte
575 * stream occur as promptly as with the original PrintStream.
576 */
577
578 private void write(char[] buf) {
579 try {
580 synchronized (this) {
581 ensureOpen();
582 textOut.write(buf);
583 textOut.flushBuffer();
584 charOut.flushBuffer();
585 if (autoFlush) {
586 for (int i = 0; i < buf.length; i++)
587 if (buf[i] == '\n') {
588 out.flush();
589 break;
590 }
591 }
592 }
593 } catch (InterruptedIOException x) {
594 Thread.currentThread().interrupt();
595 } catch (IOException x) {
596 trouble = true;
597 }
598 }
599
600 private void writeln(char[] buf) {
601 try {
602 synchronized (this) {
603 ensureOpen();
604 textOut.write(buf);
605 textOut.newLine();
606 textOut.flushBuffer();
607 charOut.flushBuffer();
608 if (autoFlush)
609 out.flush();
610 }
611 }
612 catch (InterruptedIOException x) {
613 Thread.currentThread().interrupt();
614 }
615 catch (IOException x) {
616 trouble = true;
617 }
618 }
619
620 private void write(String s) {
621 try {
622 synchronized (this) {
623 ensureOpen();
624 textOut.write(s);
625 textOut.flushBuffer();
626 charOut.flushBuffer();
627 if (autoFlush && (s.indexOf('\n') >= 0))
628 out.flush();
629 }
630 }
631 catch (InterruptedIOException x) {
632 Thread.currentThread().interrupt();
633 }
634 catch (IOException x) {
635 trouble = true;
636 }
637 }
638
639 private void writeln(String s) {
640 try {
641 synchronized (this) {
642 ensureOpen();
643 textOut.write(s);
644 textOut.newLine();
645 textOut.flushBuffer();
646 charOut.flushBuffer();
647 if (autoFlush)
648 out.flush();
649 }
650 }
651 catch (InterruptedIOException x) {
652 Thread.currentThread().interrupt();
653 }
654 catch (IOException x) {
655 trouble = true;
656 }
657 }
658
659 private void newLine() {
660 try {
661 synchronized (this) {
662 ensureOpen();
663 textOut.newLine();
664 textOut.flushBuffer();
665 charOut.flushBuffer();
666 if (autoFlush)
667 out.flush();
668 }
669 }
670 catch (InterruptedIOException x) {
671 Thread.currentThread().interrupt();
672 }
673 catch (IOException x) {
674 trouble = true;
675 }
676 }
677
678 /* Methods that do not terminate lines */
679
680 /**
681 * Prints a boolean value. The string produced by {@link
682 * java.lang.String#valueOf(boolean)} is translated into bytes
683 * according to the platform's default character encoding, and these bytes
684 * are written in exactly the manner of the
685 * {@link #write(int)} method.
686 *
687 * @param b The {@code boolean} to be printed
688 */
689 public void print(boolean b) {
690 write(String.valueOf(b));
691 }
692
693 /**
694 * Prints a character. The character is translated into one or more bytes
695 * according to the platform's default character encoding, and these bytes
696 * are written in exactly the manner of the
697 * {@link #write(int)} method.
698 *
699 * @param c The {@code char} to be printed
700 */
701 public void print(char c) {
702 write(String.valueOf(c));
703 }
704
705 /**
706 * Prints an integer. The string produced by {@link
707 * java.lang.String#valueOf(int)} is translated into bytes
708 * according to the platform's default character encoding, and these bytes
709 * are written in exactly the manner of the
710 * {@link #write(int)} method.
711 *
712 * @param i The {@code int} to be printed
713 * @see java.lang.Integer#toString(int)
714 */
715 public void print(int i) {
716 write(String.valueOf(i));
717 }
718
719 /**
720 * Prints a long integer. The string produced by {@link
721 * java.lang.String#valueOf(long)} is translated into bytes
722 * according to the platform's default character encoding, and these bytes
723 * are written in exactly the manner of the
724 * {@link #write(int)} method.
725 *
726 * @param l The {@code long} to be printed
727 * @see java.lang.Long#toString(long)
728 */
729 public void print(long l) {
730 write(String.valueOf(l));
731 }
732
733 /**
734 * Prints a floating-point number. The string produced by {@link
735 * java.lang.String#valueOf(float)} is translated into bytes
736 * according to the platform's default character encoding, and these bytes
737 * are written in exactly the manner of the
738 * {@link #write(int)} method.
739 *
740 * @param f The {@code float} to be printed
741 * @see java.lang.Float#toString(float)
742 */
743 public void print(float f) {
744 write(String.valueOf(f));
745 }
746
747 /**
748 * Prints a double-precision floating-point number. The string produced by
749 * {@link java.lang.String#valueOf(double)} is translated into
750 * bytes according to the platform's default character encoding, and these
751 * bytes are written in exactly the manner of the {@link
752 * #write(int)} method.
753 *
754 * @param d The {@code double} to be printed
755 * @see java.lang.Double#toString(double)
756 */
757 public void print(double d) {
758 write(String.valueOf(d));
759 }
760
761 /**
762 * Prints an array of characters. The characters are converted into bytes
763 * according to the platform's default character encoding, and these bytes
764 * are written in exactly the manner of the
765 * {@link #write(int)} method.
766 *
767 * @param s The array of chars to be printed
768 *
769 * @throws NullPointerException If {@code s} is {@code null}
770 */
771 public void print(char s[]) {
772 write(s);
773 }
774
775 /**
776 * Prints a string. If the argument is {@code null} then the string
777 * {@code "null"} is printed. Otherwise, the string's characters are
778 * converted into bytes according to the platform's default character
779 * encoding, and these bytes are written in exactly the manner of the
780 * {@link #write(int)} method.
781 *
782 * @param s The {@code String} to be printed
783 */
784 public void print(String s) {
785 write(String.valueOf(s));
786 }
787
788 /**
789 * Prints an object. The string produced by the {@link
790 * java.lang.String#valueOf(Object)} method is translated into bytes
791 * according to the platform's default character encoding, and these bytes
792 * are written in exactly the manner of the
793 * {@link #write(int)} method.
794 *
795 * @param obj The {@code Object} to be printed
796 * @see java.lang.Object#toString()
797 */
798 public void print(Object obj) {
799 write(String.valueOf(obj));
800 }
801
802
803 /* Methods that do terminate lines */
804
805 /**
806 * Terminates the current line by writing the line separator string. The
807 * line separator string is defined by the system property
808 * {@code line.separator}, and is not necessarily a single newline
809 * character ({@code '\n'}).
810 */
811 public void println() {
812 newLine();
813 }
814
815 /**
816 * Prints a boolean and then terminate the line. This method behaves as
817 * though it invokes {@link #print(boolean)} and then
818 * {@link #println()}.
819 *
820 * @param x The {@code boolean} to be printed
821 */
822 public void println(boolean x) {
823 if (getClass() == PrintStream.class) {
824 writeln(String.valueOf(x));
825 } else {
826 synchronized (this) {
827 print(x);
828 newLine();
829 }
830 }
831 }
832
833 /**
834 * Prints a character and then terminate the line. This method behaves as
835 * though it invokes {@link #print(char)} and then
836 * {@link #println()}.
837 *
838 * @param x The {@code char} to be printed.
839 */
840 public void println(char x) {
841 if (getClass() == PrintStream.class) {
842 writeln(String.valueOf(x));
843 } else {
844 synchronized (this) {
845 print(x);
846 newLine();
847 }
848 }
849 }
850
851 /**
852 * Prints an integer and then terminate the line. This method behaves as
853 * though it invokes {@link #print(int)} and then
854 * {@link #println()}.
855 *
856 * @param x The {@code int} to be printed.
857 */
858 public void println(int x) {
859 if (getClass() == PrintStream.class) {
860 writeln(String.valueOf(x));
861 } else {
862 synchronized (this) {
863 print(x);
864 newLine();
865 }
866 }
867 }
868
869 /**
870 * Prints a long and then terminate the line. This method behaves as
871 * though it invokes {@link #print(long)} and then
872 * {@link #println()}.
873 *
874 * @param x a The {@code long} to be printed.
875 */
876 public void println(long x) {
877 if (getClass() == PrintStream.class) {
878 writeln(String.valueOf(x));
879 } else {
880 synchronized (this) {
881 print(x);
882 newLine();
883 }
884 }
885 }
886
887 /**
888 * Prints a float and then terminate the line. This method behaves as
889 * though it invokes {@link #print(float)} and then
890 * {@link #println()}.
891 *
892 * @param x The {@code float} to be printed.
893 */
894 public void println(float x) {
895 if (getClass() == PrintStream.class) {
896 writeln(String.valueOf(x));
897 } else {
898 synchronized (this) {
899 print(x);
900 newLine();
901 }
902 }
903 }
904
905 /**
906 * Prints a double and then terminate the line. This method behaves as
907 * though it invokes {@link #print(double)} and then
908 * {@link #println()}.
909 *
910 * @param x The {@code double} to be printed.
911 */
912 public void println(double x) {
913 if (getClass() == PrintStream.class) {
914 writeln(String.valueOf(x));
915 } else {
916 synchronized (this) {
917 print(x);
918 newLine();
919 }
920 }
921 }
922
923 /**
924 * Prints an array of characters and then terminate the line. This method
925 * behaves as though it invokes {@link #print(char[])} and
926 * then {@link #println()}.
927 *
928 * @param x an array of chars to print.
929 */
930 public void println(char[] x) {
931 if (getClass() == PrintStream.class) {
932 writeln(x);
933 } else {
934 synchronized (this) {
935 print(x);
936 newLine();
937 }
938 }
939 }
940
941 /**
942 * Prints a String and then terminate the line. This method behaves as
943 * though it invokes {@link #print(String)} and then
944 * {@link #println()}.
945 *
946 * @param x The {@code String} to be printed.
947 */
948 public void println(String x) {
949 if (getClass() == PrintStream.class) {
950 writeln(String.valueOf(x));
951 } else {
952 synchronized (this) {
953 print(x);
954 newLine();
955 }
956 }
957 }
958
959 /**
960 * Prints an Object and then terminate the line. This method calls
961 * at first String.valueOf(x) to get the printed object's string value,
962 * then behaves as
963 * though it invokes {@link #print(String)} and then
964 * {@link #println()}.
965 *
966 * @param x The {@code Object} to be printed.
967 */
968 public void println(Object x) {
969 String s = String.valueOf(x);
970 if (getClass() == PrintStream.class) {
971 // need to apply String.valueOf again since first invocation
972 // might return null
973 writeln(String.valueOf(s));
974 } else {
975 synchronized (this) {
976 print(s);
977 newLine();
978 }
979 }
980 }
981
982
983 /**
984 * A convenience method to write a formatted string to this output stream
985 * using the specified format string and arguments.
986 *
987 * <p> An invocation of this method of the form
988 * {@code out.printf(format, args)} behaves
989 * in exactly the same way as the invocation
990 *
991 * <pre>{@code
992 * out.format(format, args)
993 * }</pre>
994 *
995 * @param format
996 * A format string as described in <a
997 * href="../util/Formatter.html#syntax">Format string syntax</a>
998 *
999 * @param args
1000 * Arguments referenced by the format specifiers in the format
1001 * string. If there are more arguments than format specifiers, the
1002 * extra arguments are ignored. The number of arguments is
1003 * variable and may be zero. The maximum number of arguments is
1004 * limited by the maximum dimension of a Java array as defined by
1005 * <cite>The Java™ Virtual Machine Specification</cite>.
1006 * The behaviour on a
1007 * {@code null} argument depends on the <a
1008 * href="../util/Formatter.html#syntax">conversion</a>.
1009 *
1010 * @throws java.util.IllegalFormatException
1011 * If a format string contains an illegal syntax, a format
1012 * specifier that is incompatible with the given arguments,
1013 * insufficient arguments given the format string, or other
1014 * illegal conditions. For specification of all possible
1015 * formatting errors, see the <a
1016 * href="../util/Formatter.html#detail">Details</a> section of the
1017 * formatter class specification.
1018 *
1019 * @throws NullPointerException
1020 * If the {@code format} is {@code null}
1021 *
1022 * @return This output stream
1023 *
1024 * @since 1.5
1025 */
1026 public PrintStream printf(String format, Object ... args) {
1027 return format(format, args);
1028 }
1029
1030 /**
1031 * A convenience method to write a formatted string to this output stream
1032 * using the specified format string and arguments.
1033 *
1034 * <p> An invocation of this method of the form
1035 * {@code out.printf(l, format, args)} behaves
1036 * in exactly the same way as the invocation
1037 *
1038 * <pre>{@code
1039 * out.format(l, format, args)
1040 * }</pre>
1041 *
1042 * @param l
1043 * The {@linkplain java.util.Locale locale} to apply during
1044 * formatting. If {@code l} is {@code null} then no localization
1045 * is applied.
1046 *
1047 * @param format
1048 * A format string as described in <a
1049 * href="../util/Formatter.html#syntax">Format string syntax</a>
1050 *
1051 * @param args
1052 * Arguments referenced by the format specifiers in the format
1053 * string. If there are more arguments than format specifiers, the
1054 * extra arguments are ignored. The number of arguments is
1055 * variable and may be zero. The maximum number of arguments is
1056 * limited by the maximum dimension of a Java array as defined by
1057 * <cite>The Java™ Virtual Machine Specification</cite>.
1058 * The behaviour on a
1059 * {@code null} argument depends on the <a
1060 * href="../util/Formatter.html#syntax">conversion</a>.
1061 *
1062 * @throws java.util.IllegalFormatException
1063 * If a format string contains an illegal syntax, a format
1064 * specifier that is incompatible with the given arguments,
1065 * insufficient arguments given the format string, or other
1066 * illegal conditions. For specification of all possible
1067 * formatting errors, see the <a
1068 * href="../util/Formatter.html#detail">Details</a> section of the
1069 * formatter class specification.
1070 *
1071 * @throws NullPointerException
1072 * If the {@code format} is {@code null}
1073 *
1074 * @return This output stream
1075 *
1076 * @since 1.5
1077 */
1078 public PrintStream printf(Locale l, String format, Object ... args) {
1079 return format(l, format, args);
1080 }
1081
1082 /**
1083 * Writes a formatted string to this output stream using the specified
1084 * format string and arguments.
1085 *
1086 * <p> The locale always used is the one returned by {@link
1087 * java.util.Locale#getDefault(Locale.Category)} with
1088 * {@link java.util.Locale.Category#FORMAT FORMAT} category specified,
1089 * regardless of any previous invocations of other formatting methods on
1090 * this object.
1091 *
1092 * @param format
1093 * A format string as described in <a
1094 * href="../util/Formatter.html#syntax">Format string syntax</a>
1095 *
1096 * @param args
1097 * Arguments referenced by the format specifiers in the format
1098 * string. If there are more arguments than format specifiers, the
1099 * extra arguments are ignored. The number of arguments is
1100 * variable and may be zero. The maximum number of arguments is
1101 * limited by the maximum dimension of a Java array as defined by
1102 * <cite>The Java™ Virtual Machine Specification</cite>.
1103 * The behaviour on a
1104 * {@code null} argument depends on the <a
1105 * href="../util/Formatter.html#syntax">conversion</a>.
1106 *
1107 * @throws java.util.IllegalFormatException
1108 * If a format string contains an illegal syntax, a format
1109 * specifier that is incompatible with the given arguments,
1110 * insufficient arguments given the format string, or other
1111 * illegal conditions. For specification of all possible
1112 * formatting errors, see the <a
1113 * href="../util/Formatter.html#detail">Details</a> section of the
1114 * formatter class specification.
1115 *
1116 * @throws NullPointerException
1117 * If the {@code format} is {@code null}
1118 *
1119 * @return This output stream
1120 *
1121 * @since 1.5
1122 */
1123 public PrintStream format(String format, Object ... args) {
1124 try {
1125 synchronized (this) {
1126 ensureOpen();
1127 if ((formatter == null)
1128 || (formatter.locale() !=
1129 Locale.getDefault(Locale.Category.FORMAT)))
1130 formatter = new Formatter((Appendable) this);
1131 formatter.format(Locale.getDefault(Locale.Category.FORMAT),
1132 format, args);
1133 }
1134 } catch (InterruptedIOException x) {
1135 Thread.currentThread().interrupt();
1136 } catch (IOException x) {
1137 trouble = true;
1138 }
1139 return this;
1140 }
1141
1142 /**
1143 * Writes a formatted string to this output stream using the specified
1144 * format string and arguments.
1145 *
1146 * @param l
1147 * The {@linkplain java.util.Locale locale} to apply during
1148 * formatting. If {@code l} is {@code null} then no localization
1149 * is applied.
1150 *
1151 * @param format
1152 * A format string as described in <a
1153 * href="../util/Formatter.html#syntax">Format string syntax</a>
1154 *
1155 * @param args
1156 * Arguments referenced by the format specifiers in the format
1157 * string. If there are more arguments than format specifiers, the
1158 * extra arguments are ignored. The number of arguments is
1159 * variable and may be zero. The maximum number of arguments is
1160 * limited by the maximum dimension of a Java array as defined by
1161 * <cite>The Java™ Virtual Machine Specification</cite>.
1162 * The behaviour on a
1163 * {@code null} argument depends on the <a
1164 * href="../util/Formatter.html#syntax">conversion</a>.
1165 *
1166 * @throws java.util.IllegalFormatException
1167 * If a format string contains an illegal syntax, a format
1168 * specifier that is incompatible with the given arguments,
1169 * insufficient arguments given the format string, or other
1170 * illegal conditions. For specification of all possible
1171 * formatting errors, see the <a
1172 * href="../util/Formatter.html#detail">Details</a> section of the
1173 * formatter class specification.
1174 *
1175 * @throws NullPointerException
1176 * If the {@code format} is {@code null}
1177 *
1178 * @return This output stream
1179 *
1180 * @since 1.5
1181 */
1182 public PrintStream format(Locale l, String format, Object ... args) {
1183 try {
1184 synchronized (this) {
1185 ensureOpen();
1186 if ((formatter == null)
1187 || (formatter.locale() != l))
1188 formatter = new Formatter(this, l);
1189 formatter.format(l, format, args);
1190 }
1191 } catch (InterruptedIOException x) {
1192 Thread.currentThread().interrupt();
1193 } catch (IOException x) {
1194 trouble = true;
1195 }
1196 return this;
1197 }
1198
1199 /**
1200 * Appends the specified character sequence to this output stream.
1201 *
1202 * <p> An invocation of this method of the form {@code out.append(csq)}
1203 * behaves in exactly the same way as the invocation
1204 *
1205 * <pre>{@code
1206 * out.print(csq.toString())
1207 * }</pre>
1208 *
1209 * <p> Depending on the specification of {@code toString} for the
1210 * character sequence {@code csq}, the entire sequence may not be
1211 * appended. For instance, invoking then {@code toString} method of a
1212 * character buffer will return a subsequence whose content depends upon
1213 * the buffer's position and limit.
1214 *
1215 * @param csq
1216 * The character sequence to append. If {@code csq} is
1217 * {@code null}, then the four characters {@code "null"} are
1218 * appended to this output stream.
1219 *
1220 * @return This output stream
1221 *
1222 * @since 1.5
1223 */
1224 public PrintStream append(CharSequence csq) {
1225 print(String.valueOf(csq));
1226 return this;
1227 }
1228
1229 /**
1230 * Appends a subsequence of the specified character sequence to this output
1231 * stream.
1232 *
1233 * <p> An invocation of this method of the form
1234 * {@code out.append(csq, start, end)} when
1235 * {@code csq} is not {@code null}, behaves in
1236 * exactly the same way as the invocation
1237 *
1238 * <pre>{@code
1239 * out.print(csq.subSequence(start, end).toString())
1240 * }</pre>
1241 *
1242 * @param csq
1243 * The character sequence from which a subsequence will be
1244 * appended. If {@code csq} is {@code null}, then characters
1245 * will be appended as if {@code csq} contained the four
1246 * characters {@code "null"}.
1247 *
1248 * @param start
1249 * The index of the first character in the subsequence
1250 *
1251 * @param end
1252 * The index of the character following the last character in the
1253 * subsequence
1254 *
1255 * @return This output stream
1256 *
1257 * @throws IndexOutOfBoundsException
1258 * If {@code start} or {@code end} are negative, {@code start}
1259 * is greater than {@code end}, or {@code end} is greater than
1260 * {@code csq.length()}
1261 *
1262 * @since 1.5
1263 */
1264 public PrintStream append(CharSequence csq, int start, int end) {
1265 if (csq == null) csq = "null";
1266 return append(csq.subSequence(start, end));
1267 }
1268
1269 /**
1270 * Appends the specified character to this output stream.
1271 *
1272 * <p> An invocation of this method of the form {@code out.append(c)}
1273 * behaves in exactly the same way as the invocation
1274 *
1275 * <pre>{@code
1276 * out.print(c)
1277 * }</pre>
1278 *
1279 * @param c
1280 * The 16-bit character to append
1281 *
1282 * @return This output stream
1283 *
1284 * @since 1.5
1285 */
1286 public PrintStream append(char c) {
1287 print(c);
1288 return this;
1289 }
1290
1291 }