Repository navigation
Expand file tree
/
Copy pathInputStream.java
More file actions
807 lines (761 loc) · 32.9 KB
/
Copy pathInputStream.java
File metadata and controls
807 lines (761 loc) · 32.9 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
/*
* Copyright (c) 1994, 2024, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation. Oracle designates this
* particular file as subject to the "Classpath" exception as provided
* by Oracle in the LICENSE file that accompanied this code.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
package java.io;
import jdk.internal.util.ArraysSupport;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
import java.util.Objects;
/**
* This abstract class is the superclass of all classes representing
* an input stream of bytes.
*
* <p> Applications that need to define a subclass of {@code InputStream}
* must always provide a method that returns the next byte of input.
*
* @author Arthur van Hoff
* @see java.io.BufferedInputStream
* @see java.io.ByteArrayInputStream
* @see java.io.DataInputStream
* @see java.io.FilterInputStream
* @see java.io.InputStream#read()
* @see java.io.OutputStream
* @see java.io.PushbackInputStream
* @since 1.0
*/
public abstract class InputStream implements Closeable {
// MAX_SKIP_BUFFER_SIZE is used to determine the maximum buffer size to
// use when skipping.
private static final int MAX_SKIP_BUFFER_SIZE = 2048;
private static final int DEFAULT_BUFFER_SIZE = 16384;
/**
* Constructor for subclasses to call.
*/
public InputStream() {}
/**
* Returns a new {@code InputStream} that reads no bytes. The returned
* stream is initially open. The stream is closed by calling the
* {@code close()} method. Subsequent calls to {@code close()} have no
* effect.
*
* <p> While the stream is open, the {@code available()}, {@code read()},
* {@code read(byte[])}, {@code read(byte[], int, int)},
* {@code readAllBytes()}, {@code readNBytes(byte[], int, int)},
* {@code readNBytes(int)}, {@code skip(long)}, {@code skipNBytes(long)},
* and {@code transferTo()} methods all behave as if end of stream has been
* reached. After the stream has been closed, these methods all throw
* {@code IOException}.
*
* <p> The {@code markSupported()} method returns {@code false}. The
* {@code mark()} method does nothing, and the {@code reset()} method
* throws {@code IOException}.
*
* @return an {@code InputStream} which contains no bytes
*
* @since 11
*/
public static InputStream nullInputStream() {
return new InputStream() {
private volatile boolean closed;
private void ensureOpen() throws IOException {
if (closed) {
throw new IOException("Stream closed");
}
}
@Override
public int available () throws IOException {
ensureOpen();
return 0;
}
@Override
public int read() throws IOException {
ensureOpen();
return -1;
}
@Override
public int read(byte[] b, int off, int len) throws IOException {
Objects.checkFromIndexSize(off, len, b.length);
if (len == 0) {
return 0;
}
ensureOpen();
return -1;
}
@Override
public byte[] readAllBytes() throws IOException {
ensureOpen();
return new byte[0];
}
@Override
public int readNBytes(byte[] b, int off, int len)
throws IOException {
Objects.checkFromIndexSize(off, len, b.length);
ensureOpen();
return 0;
}
@Override
public byte[] readNBytes(int len) throws IOException {
if (len < 0) {
throw new IllegalArgumentException("len < 0");
}
ensureOpen();
return new byte[0];
}
@Override
public long skip(long n) throws IOException {
ensureOpen();
return 0L;
}
@Override
public void skipNBytes(long n) throws IOException {
ensureOpen();
if (n > 0) {
throw new EOFException();
}
}
@Override
public long transferTo(OutputStream out) throws IOException {
Objects.requireNonNull(out);
ensureOpen();
return 0L;
}
@Override
public void close() throws IOException {
closed = true;
}
};
}
/**
* Reads the next byte of data from the input stream. The value byte is
* returned as an {@code int} in the range {@code 0} to
* {@code 255}. If no byte is available because the end of the stream
* has been reached, the value {@code -1} is returned. This method
* blocks until input data is available, the end of the stream is detected,
* or an exception is thrown.
*
* @return the next byte of data, or {@code -1} if the end of the
* stream is reached.
* @throws IOException if an I/O error occurs.
*/
public abstract int read() throws IOException;
/**
* Reads some number of bytes from the input stream and stores them into
* the buffer array {@code b}. The number of bytes actually read is
* returned as an integer. This method blocks until input data is
* available, end of file is detected, or an exception is thrown.
*
* <p> If the length of {@code b} is zero, then no bytes are read and
* {@code 0} is returned; otherwise, there is an attempt to read at
* least one byte. If no byte is available because the stream is at the
* end of the file, the value {@code -1} is returned; otherwise, at
* least one byte is read and stored into {@code b}.
*
* <p> The first byte read is stored into element {@code b[0]}, the
* next one into {@code b[1]}, and so on. The number of bytes read is,
* at most, equal to the length of {@code b}. Let <i>k</i> be the
* number of bytes actually read; these bytes will be stored in elements
* {@code b[0]} through {@code b[}<i>k</i>{@code -1]},
* leaving elements {@code b[}<i>k</i>{@code ]} through
* {@code b[b.length-1]} unaffected.
*
* @implSpec
* The {@code read(b)} method for class {@code InputStream}
* has the same effect as:
* {@snippet lang=java :
* read(b, 0, b.length)
* }
*
* @param b the buffer into which the data is read.
* @return the total number of bytes read into the buffer, or
* {@code -1} if there is no more data because the end of
* the stream has been reached.
* @throws IOException If the first byte cannot be read for any reason
* other than the end of the file, if the input stream has been
* closed, or if some other I/O error occurs.
* @throws NullPointerException if {@code b} is {@code null}.
* @see java.io.InputStream#read(byte[], int, int)
*/
public int read(byte[] b) throws IOException {
return read(b, 0, b.length);
}
/**
* Reads up to {@code len} bytes of data from the input stream into
* an array of bytes. An attempt is made to read as many as
* {@code len} bytes, but a smaller number may be read.
* The number of bytes actually read is returned as an integer.
*
* <p> This method blocks until input data is available, end of file is
* detected, or an exception is thrown.
*
* <p> If {@code len} is zero, then no bytes are read and
* {@code 0} is returned; otherwise, there is an attempt to read at
* least one byte. If no byte is available because the stream is at end of
* file, the value {@code -1} is returned; otherwise, at least one
* byte is read and stored into {@code b}.
*
* <p> The first byte read is stored into element {@code b[off]}, the
* next one into {@code b[off+1]}, and so on. The number of bytes read
* is, at most, equal to {@code len}. Let <i>k</i> be the number of
* bytes actually read; these bytes will be stored in elements
* {@code b[off]} through {@code b[off+}<i>k</i>{@code -1]},
* leaving elements {@code b[off+}<i>k</i>{@code ]} through
* {@code b[off+len-1]} unaffected.
*
* <p> In every case, elements {@code b[0]} through
* {@code b[off-1]} and elements {@code b[off+len]} through
* {@code b[b.length-1]} are unaffected.
*
* @implSpec
* The {@code read(b, off, len)} method
* for class {@code InputStream} simply calls the method
* {@code read()} repeatedly. If the first such call results in an
* {@code IOException}, that exception is returned from the call to
* the {@code read(b,} {@code off,} {@code len)} method. If
* any subsequent call to {@code read()} results in a
* {@code IOException}, the exception is caught and treated as if it
* were end of file; the bytes read up to that point are stored into
* {@code b} and the number of bytes read before the exception
* occurred is returned. The default implementation of this method blocks
* until the requested amount of input data {@code len} has been read,
* end of file is detected, or an exception is thrown. Subclasses are
* encouraged to provide a more efficient implementation of this method.
*
* @param b the buffer into which the data is read.
* @param off the start offset in array {@code b}
* at which the data is written.
* @param len the maximum number of bytes to read.
* @return the total number of bytes read into the buffer, or
* {@code -1} if there is no more data because the end of
* the stream has been reached.
* @throws IOException If the first byte cannot be read for any reason
* other than end of file, or if the input stream has been closed,
* or if some other I/O error occurs.
* @throws NullPointerException If {@code b} is {@code null}.
* @throws IndexOutOfBoundsException If {@code off} is negative,
* {@code len} is negative, or {@code len} is greater than
* {@code b.length - off}
* @see java.io.InputStream#read()
*/
public int read(byte[] b, int off, int len) throws IOException {
Objects.checkFromIndexSize(off, len, b.length);
if (len == 0) {
return 0;
}
int c = read();
if (c == -1) {
return -1;
}
b[off] = (byte)c;
int i = 1;
try {
for (; i < len ; i++) {
c = read();
if (c == -1) {
break;
}
b[off + i] = (byte)c;
}
} catch (IOException ee) {
}
return i;
}
/**
* The maximum size of array to allocate
*/
private static final int MAX_BUFFER_SIZE = ArraysSupport.SOFT_MAX_ARRAY_LENGTH;
/**
* Reads all remaining bytes from the input stream. This method blocks until
* all remaining bytes have been read and end of stream is detected, or an
* exception is thrown. This method does not close the input stream.
*
* <p> When this stream reaches end of stream, further invocations of this
* method will return an empty byte array.
*
* <p> Note that this method is intended for simple cases where it is
* convenient to read all bytes into a byte array. It is not intended for
* reading input streams with large amounts of data.
*
* <p> The behavior for the case where the input stream is <i>asynchronously
* closed</i>, or the thread interrupted during the read, is highly input
* stream specific, and therefore not specified.
*
* <p> If an I/O error occurs reading from the input stream, then it may do
* so after some, but not all, bytes have been read. Consequently the input
* stream may not be at end of stream and may be in an inconsistent state.
* It is strongly recommended that the stream be promptly closed if an I/O
* error occurs.
*
* @implSpec
* This method invokes {@link #readNBytes(int)} with a length of
* {@link Integer#MAX_VALUE}.
*
* @return a byte array containing the bytes read from this input stream
* @throws IOException if an I/O error occurs
* @throws OutOfMemoryError if an array of the required size cannot be
* allocated.
*
* @since 9
*/
public byte[] readAllBytes() throws IOException {
return readNBytes(Integer.MAX_VALUE);
}
/**
* Reads up to a specified number of bytes from the input stream. This
* method blocks until the requested number of bytes has been read, end
* of stream is detected, or an exception is thrown. This method does not
* close the input stream.
*
* <p> The length of the returned array equals the number of bytes read
* from the stream. If {@code len} is zero, then no bytes are read and
* an empty byte array is returned. Otherwise, up to {@code len} bytes
* are read from the stream. Fewer than {@code len} bytes may be read if
* end of stream is encountered.
*
* <p> When this stream reaches end of stream, further invocations of this
* method will return an empty byte array.
*
* <p> Note that this method is intended for simple cases where it is
* convenient to read the specified number of bytes into a byte array. The
* total amount of memory allocated by this method is proportional to the
* number of bytes read from the stream which is bounded by {@code len}.
* Therefore, the method may be safely called with very large values of
* {@code len} provided sufficient memory is available.
*
* <p> The behavior for the case where the input stream is <i>asynchronously
* closed</i>, or the thread interrupted during the read, is highly input
* stream specific, and therefore not specified.
*
* <p> If an I/O error occurs reading from the input stream, then it may do
* so after some, but not all, bytes have been read. Consequently the input
* stream may not be at end of stream and may be in an inconsistent state.
* It is strongly recommended that the stream be promptly closed if an I/O
* error occurs.
*
* @implNote
* The number of bytes allocated to read data from this stream and return
* the result is bounded by {@code 2*(long)len}, inclusive.
*
* @param len the maximum number of bytes to read
* @return a byte array containing the bytes read from this input stream
* @throws IllegalArgumentException if {@code length} is negative
* @throws IOException if an I/O error occurs
* @throws OutOfMemoryError if an array of the required size cannot be
* allocated.
*
* @since 11
*/
public byte[] readNBytes(int len) throws IOException {
if (len < 0) {
throw new IllegalArgumentException("len < 0");
}
List<byte[]> bufs = null;
byte[] result = null;
int total = 0;
int remaining = len;
int n;
do {
byte[] buf = new byte[Math.min(remaining, DEFAULT_BUFFER_SIZE)];
int nread = 0;
// read to EOF which may read more or less than buffer size
while ((n = read(buf, nread,
Math.min(buf.length - nread, remaining))) > 0) {
nread += n;
remaining -= n;
}
if (nread > 0) {
if (MAX_BUFFER_SIZE - total < nread) {
throw new OutOfMemoryError("Required array size too large");
}
if (nread < buf.length) {
buf = Arrays.copyOfRange(buf, 0, nread);
}
total += nread;
if (result == null) {
result = buf;
} else {
if (bufs == null) {
bufs = new ArrayList<>();
bufs.add(result);
}
bufs.add(buf);
}
}
// if the last call to read returned -1 or the number of bytes
// requested have been read then break
} while (n >= 0 && remaining > 0);
if (bufs == null) {
if (result == null) {
return new byte[0];
}
return result.length == total ?
result : Arrays.copyOf(result, total);
}
result = new byte[total];
int offset = 0;
remaining = total;
for (byte[] b : bufs) {
int count = Math.min(b.length, remaining);
System.arraycopy(b, 0, result, offset, count);
offset += count;
remaining -= count;
}
return result;
}
/**
* Reads the requested number of bytes from the input stream into the given
* byte array. This method blocks until {@code len} bytes of input data have
* been read, end of stream is detected, or an exception is thrown. The
* number of bytes actually read, possibly zero, is returned. This method
* does not close the input stream.
*
* <p> In the case where end of stream is reached before {@code len} bytes
* have been read, then the actual number of bytes read will be returned.
* When this stream reaches end of stream, further invocations of this
* method will return zero.
*
* <p> If {@code len} is zero, then no bytes are read and {@code 0} is
* returned; otherwise, there is an attempt to read up to {@code len} bytes.
*
* <p> The first byte read is stored into element {@code b[off]}, the next
* one in to {@code b[off+1]}, and so on. The number of bytes read is, at
* most, equal to {@code len}. Let <i>k</i> be the number of bytes actually
* read; these bytes will be stored in elements {@code b[off]} through
* {@code b[off+}<i>k</i>{@code -1]}, leaving elements {@code b[off+}<i>k</i>
* {@code ]} through {@code b[off+len-1]} unaffected.
*
* <p> The behavior for the case where the input stream is <i>asynchronously
* closed</i>, or the thread interrupted during the read, is highly input
* stream specific, and therefore not specified.
*
* <p> If an I/O error occurs reading from the input stream, then it may do
* so after some, but not all, bytes of {@code b} have been updated with
* data from the input stream. Consequently the input stream and {@code b}
* may be in an inconsistent state. It is strongly recommended that the
* stream be promptly closed if an I/O error occurs.
*
* @param b the byte array into which the data is read
* @param off the start offset in {@code b} at which the data is written
* @param len the maximum number of bytes to read
* @return the actual number of bytes read into the buffer
* @throws IOException if an I/O error occurs
* @throws NullPointerException if {@code b} is {@code null}
* @throws IndexOutOfBoundsException If {@code off} is negative, {@code len}
* is negative, or {@code len} is greater than {@code b.length - off}
*
* @since 9
*/
public int readNBytes(byte[] b, int off, int len) throws IOException {
Objects.checkFromIndexSize(off, len, b.length);
int n = 0;
while (n < len) {
int count = read(b, off + n, len - n);
if (count < 0)
break;
n += count;
}
return n;
}
/**
* Skips over and discards {@code n} bytes of data from this input
* stream. The {@code skip} method may, for a variety of reasons, end
* up skipping over some smaller number of bytes, possibly {@code 0}.
* This may result from any of a number of conditions; reaching end of file
* before {@code n} bytes have been skipped is only one possibility.
* The actual number of bytes skipped is returned. If {@code n} is
* negative, the {@code skip} method for class {@code InputStream} always
* returns 0, and no bytes are skipped. Subclasses may handle the negative
* value differently.
*
* @implSpec
* The {@code skip} method implementation of this class creates a
* byte array and then repeatedly reads into it until {@code n} bytes
* have been read or the end of the stream has been reached. Subclasses are
* encouraged to provide a more efficient implementation of this method.
* For instance, the implementation may depend on the ability to seek.
*
* @param n the number of bytes to be skipped.
* @return the actual number of bytes skipped which might be zero.
* @throws IOException if an I/O error occurs.
* @see java.io.InputStream#skipNBytes(long)
*/
public long skip(long n) throws IOException {
long remaining = n;
int nr;
if (n <= 0) {
return 0;
}
int size = (int)Math.min(MAX_SKIP_BUFFER_SIZE, remaining);
byte[] skipBuffer = new byte[size];
while (remaining > 0) {
nr = read(skipBuffer, 0, (int)Math.min(size, remaining));
if (nr < 0) {
break;
}
remaining -= nr;
}
return n - remaining;
}
/**
* Skips over and discards exactly {@code n} bytes of data from this input
* stream. If {@code n} is zero, then no bytes are skipped.
* If {@code n} is negative, then no bytes are skipped.
* Subclasses may handle the negative value differently.
*
* <p> This method blocks until the requested number of bytes has been
* skipped, end of file is reached, or an exception is thrown.
*
* <p> If end of stream is reached before the stream is at the desired
* position, then an {@code EOFException} is thrown.
*
* <p> If an I/O error occurs, then the input stream may be
* in an inconsistent state. It is strongly recommended that the
* stream be promptly closed if an I/O error occurs.
*
* @implNote
* Subclasses are encouraged to provide a more efficient implementation
* of this method.
*
* @implSpec
* If {@code n} is zero or negative, then no bytes are skipped.
* If {@code n} is positive, the default implementation of this method
* invokes {@link #skip(long) skip()} repeatedly with its parameter equal
* to the remaining number of bytes to skip until the requested number
* of bytes has been skipped or an error condition occurs. If at any
* point the return value of {@code skip()} is negative or greater than the
* remaining number of bytes to be skipped, then an {@code IOException} is
* thrown. If {@code skip()} ever returns zero, then {@link #read()} is
* invoked to read a single byte, and if it returns {@code -1}, then an
* {@code EOFException} is thrown. Any exception thrown by {@code skip()}
* or {@code read()} will be propagated.
*
* @param n the number of bytes to be skipped.
* @throws EOFException if end of stream is encountered before the
* stream can be positioned {@code n} bytes beyond its position
* when this method was invoked.
* @throws IOException if the stream cannot be positioned properly or
* if an I/O error occurs.
* @see java.io.InputStream#skip(long)
*
* @since 12
*/
public void skipNBytes(long n) throws IOException {
while (n > 0) {
long ns = skip(n);
if (ns > 0 && ns <= n) {
// adjust number to skip
n -= ns;
} else if (ns == 0) { // no bytes skipped
// read one byte to check for EOS
if (read() == -1) {
throw new EOFException();
}
// one byte read so decrement number to skip
n--;
} else { // skipped negative or too many bytes
throw new IOException("Unable to skip exactly");
}
}
}
/**
* Returns an estimate of the number of bytes that can be read (or skipped
* over) from this input stream without blocking, which may be 0, or 0 when
* end of stream is detected. The read might be on the same thread or
* another thread. A single read or skip of this many bytes will not block,
* but may read or skip fewer bytes.
*
* <p> Note that while some implementations of {@code InputStream} will
* return the total number of bytes in the stream, many will not. It is
* never correct to use the return value of this method to allocate
* a buffer intended to hold all data in this stream.
*
* <p> A subclass's implementation of this method may choose to throw an
* {@link IOException} if this input stream has been closed by invoking the
* {@link #close()} method.
*
* @implSpec
* The {@code available} method of {@code InputStream} always returns
* {@code 0}.
*
* @apiNote
* This method should be overridden by subclasses.
*
* @return an estimate of the number of bytes that can be read (or
* skipped over) from this input stream without blocking or
* {@code 0} when it reaches the end of the input stream.
* @throws IOException if an I/O error occurs.
*/
public int available() throws IOException {
return 0;
}
/**
* Closes this input stream and releases any system resources associated
* with the stream.
*
* @implSpec
* The {@code close} method of {@code InputStream} does
* nothing.
*
* @throws IOException if an I/O error occurs.
*/
public void close() throws IOException {}
/**
* Marks the current position in this input stream. A subsequent call to
* the {@code reset} method repositions this stream at the last marked
* position so that subsequent reads re-read the same bytes.
*
* <p> The {@code readlimit} arguments tells this input stream to
* allow that many bytes to be read before the mark position gets
* invalidated.
*
* <p> The general contract of {@code mark} is that, if the method
* {@code markSupported} returns {@code true}, the stream somehow
* remembers all the bytes read after the call to {@code mark} and
* stands ready to supply those same bytes again if and whenever the method
* {@code reset} is called. However, the stream is not required to
* remember any data at all if more than {@code readlimit} bytes are
* read from the stream before {@code reset} is called.
*
* <p> Marking a closed stream should not have any effect on the stream.
*
* @implSpec
* The {@code mark} method of {@code InputStream} does nothing.
*
* @param readlimit the maximum limit of bytes that can be read before
* the mark position becomes invalid.
* @see java.io.InputStream#reset()
*/
public void mark(int readlimit) {}
/**
* Repositions this stream to the position at the time the
* {@code mark} method was last called on this input stream.
*
* <p> The general contract of {@code reset} is:
*
* <ul>
* <li> If the method {@code markSupported} returns
* {@code true}, then:
*
* <ul><li> If the method {@code mark} has not been called since
* the stream was created, or the number of bytes read from the stream
* since {@code mark} was last called is larger than the argument
* to {@code mark} at that last call, then an
* {@code IOException} might be thrown.
*
* <li> If such an {@code IOException} is not thrown, then the
* stream is reset to a state such that all the bytes read since the
* most recent call to {@code mark} (or since the start of the
* file, if {@code mark} has not been called) will be resupplied
* to subsequent callers of the {@code read} method, followed by
* any bytes that otherwise would have been the next input data as of
* the time of the call to {@code reset}. </ul>
*
* <li> If the method {@code markSupported} returns
* {@code false}, then:
*
* <ul><li> The call to {@code reset} may throw an
* {@code IOException}.
*
* <li> If an {@code IOException} is not thrown, then the stream
* is reset to a fixed state that depends on the particular type of the
* input stream and how it was created. The bytes that will be supplied
* to subsequent callers of the {@code read} method depend on the
* particular type of the input stream. </ul></ul>
*
* @implSpec
* The method {@code reset} for class {@code InputStream}
* does nothing except throw an {@code IOException}.
*
* @throws IOException if this stream has not been marked or if the
* mark has been invalidated.
* @see java.io.InputStream#mark(int)
* @see java.io.IOException
*/
public void reset() throws IOException {
throw new IOException("mark/reset not supported");
}
/**
* Tests if this input stream supports the {@code mark} and
* {@code reset} methods. Whether or not {@code mark} and
* {@code reset} are supported is an invariant property of a
* particular input stream instance.
*
* @implSpec
* The {@code markSupported} method
* of {@code InputStream} returns {@code false}.
*
* @return {@code true} if this stream instance supports the mark
* and reset methods; {@code false} otherwise.
* @see java.io.InputStream#mark(int)
* @see java.io.InputStream#reset()
*/
public boolean markSupported() {
return false;
}
/**
* Reads all bytes from this input stream and writes the bytes to the
* given output stream in the order that they are read. On return, this
* input stream will be at end of stream. This method does not close either
* stream.
* <p>
* This method may block indefinitely reading from the input stream, or
* writing to the output stream. The behavior for the case where the input
* and/or output stream is <i>asynchronously closed</i>, or the thread
* interrupted during the transfer, is highly input and output stream
* specific, and therefore not specified.
* <p>
* If the total number of bytes transferred is greater than {@linkplain
* Long#MAX_VALUE}, then {@code Long.MAX_VALUE} will be returned.
* <p>
* If an I/O error occurs reading from the input stream or writing to the
* output stream, then it may do so after some bytes have been read or
* written. Consequently the input stream may not be at end of stream and
* one, or both, streams may be in an inconsistent state. It is strongly
* recommended that both streams be promptly closed if an I/O error occurs.
*
* @param out the output stream, non-null
* @return the number of bytes transferred
* @throws IOException if an I/O error occurs when reading or writing
* @throws NullPointerException if {@code out} is {@code null}
*
* @since 9
*/
public long transferTo(OutputStream out) throws IOException {
Objects.requireNonNull(out, "out");
long transferred = 0;
byte[] buffer = new byte[DEFAULT_BUFFER_SIZE];
int read;
while ((read = this.read(buffer, 0, DEFAULT_BUFFER_SIZE)) >= 0) {
out.write(buffer, 0, read);
if (transferred < Long.MAX_VALUE) {
try {
transferred = Math.addExact(transferred, read);
} catch (ArithmeticException ignore) {
transferred = Long.MAX_VALUE;
}
}
}
return transferred;
}
}