001 /* 002 * Copyright (C) 2007 The Guava Authors 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017 package com.google.common.io; 018 019 import com.google.common.annotations.Beta; 020 import com.google.common.base.Preconditions; 021 022 import java.io.ByteArrayInputStream; 023 import java.io.ByteArrayOutputStream; 024 import java.io.DataInput; 025 import java.io.DataInputStream; 026 import java.io.DataOutput; 027 import java.io.DataOutputStream; 028 import java.io.EOFException; 029 import java.io.IOException; 030 import java.io.InputStream; 031 import java.io.OutputStream; 032 import java.nio.ByteBuffer; 033 import java.nio.channels.ReadableByteChannel; 034 import java.nio.channels.WritableByteChannel; 035 import java.security.MessageDigest; 036 import java.util.Arrays; 037 import java.util.zip.Checksum; 038 039 /** 040 * Provides utility methods for working with byte arrays and I/O streams. 041 * 042 * <p>All method parameters must be non-null unless documented otherwise. 043 * 044 * @author Chris Nokleberg 045 * @since 1 046 */ 047 @Beta 048 public final class ByteStreams { 049 private static final int BUF_SIZE = 0x1000; // 4K 050 051 private ByteStreams() {} 052 053 /** 054 * Returns a factory that will supply instances of 055 * {@link ByteArrayInputStream} that read from the given byte array. 056 * 057 * @param b the input buffer 058 * @return the factory 059 */ 060 public static InputSupplier<ByteArrayInputStream> newInputStreamSupplier( 061 byte[] b) { 062 return newInputStreamSupplier(b, 0, b.length); 063 } 064 065 /** 066 * Returns a factory that will supply instances of 067 * {@link ByteArrayInputStream} that read from the given byte array. 068 * 069 * @param b the input buffer 070 * @param off the offset in the buffer of the first byte to read 071 * @param len the maximum number of bytes to read from the buffer 072 * @return the factory 073 */ 074 public static InputSupplier<ByteArrayInputStream> newInputStreamSupplier( 075 final byte[] b, final int off, final int len) { 076 return new InputSupplier<ByteArrayInputStream>() { 077 @Override 078 public ByteArrayInputStream getInput() { 079 return new ByteArrayInputStream(b, off, len); 080 } 081 }; 082 } 083 084 /** 085 * Writes a byte array to an output stream from the given supplier. 086 * 087 * @param from the bytes to write 088 * @param to the output supplier 089 * @throws IOException if an I/O error occurs 090 */ 091 public static void write(byte[] from, 092 OutputSupplier<? extends OutputStream> to) throws IOException { 093 Preconditions.checkNotNull(from); 094 boolean threw = true; 095 OutputStream out = to.getOutput(); 096 try { 097 out.write(from); 098 threw = false; 099 } finally { 100 Closeables.close(out, threw); 101 } 102 } 103 104 /** 105 * Opens input and output streams from the given suppliers, copies all 106 * bytes from the input to the output, and closes the streams. 107 * 108 * @param from the input factory 109 * @param to the output factory 110 * @return the number of bytes copied 111 * @throws IOException if an I/O error occurs 112 */ 113 public static long copy(InputSupplier<? extends InputStream> from, 114 OutputSupplier<? extends OutputStream> to) throws IOException { 115 boolean threw = true; 116 InputStream in = from.getInput(); 117 try { 118 OutputStream out = to.getOutput(); 119 try { 120 long count = copy(in, out); 121 threw = false; 122 return count; 123 } finally { 124 Closeables.close(out, threw); 125 } 126 } finally { 127 Closeables.close(in, threw); 128 } 129 } 130 131 /** 132 * Opens an input stream from the supplier, copies all bytes from the 133 * input to the output, and closes the input stream. Does not close 134 * or flush the output stream. 135 * 136 * @param from the input factory 137 * @param to the output stream to write to 138 * @return the number of bytes copied 139 * @throws IOException if an I/O error occurs 140 */ 141 public static long copy(InputSupplier<? extends InputStream> from, 142 OutputStream to) throws IOException { 143 boolean threw = true; 144 InputStream in = from.getInput(); 145 try { 146 long count = copy(in, to); 147 threw = false; 148 return count; 149 } finally { 150 Closeables.close(in, threw); 151 } 152 } 153 154 /** 155 * Copies all bytes from the input stream to the output stream. 156 * Does not close or flush either stream. 157 * 158 * @param from the input stream to read from 159 * @param to the output stream to write to 160 * @return the number of bytes copied 161 * @throws IOException if an I/O error occurs 162 */ 163 public static long copy(InputStream from, OutputStream to) 164 throws IOException { 165 byte[] buf = new byte[BUF_SIZE]; 166 long total = 0; 167 while (true) { 168 int r = from.read(buf); 169 if (r == -1) { 170 break; 171 } 172 to.write(buf, 0, r); 173 total += r; 174 } 175 return total; 176 } 177 178 /** 179 * Copies all bytes from the readable channel to the writable channel. 180 * Does not close or flush either channel. 181 * 182 * @param from the readable channel to read from 183 * @param to the writable channel to write to 184 * @return the number of bytes copied 185 * @throws IOException if an I/O error occurs 186 */ 187 public static long copy(ReadableByteChannel from, 188 WritableByteChannel to) throws IOException { 189 ByteBuffer buf = ByteBuffer.allocate(BUF_SIZE); 190 long total = 0; 191 while (from.read(buf) != -1) { 192 buf.flip(); 193 while (buf.hasRemaining()) { 194 total += to.write(buf); 195 } 196 buf.clear(); 197 } 198 return total; 199 } 200 201 /** 202 * Reads all bytes from an input stream into a byte array. 203 * Does not close the stream. 204 * 205 * @param in the input stream to read from 206 * @return a byte array containing all the bytes from the stream 207 * @throws IOException if an I/O error occurs 208 */ 209 public static byte[] toByteArray(InputStream in) throws IOException { 210 ByteArrayOutputStream out = new ByteArrayOutputStream(); 211 copy(in, out); 212 return out.toByteArray(); 213 } 214 215 /** 216 * Returns the data from a {@link InputStream} factory as a byte array. 217 * 218 * @param supplier the factory 219 * @throws IOException if an I/O error occurs 220 */ 221 public static byte[] toByteArray( 222 InputSupplier<? extends InputStream> supplier) throws IOException { 223 boolean threw = true; 224 InputStream in = supplier.getInput(); 225 try { 226 byte[] result = toByteArray(in); 227 threw = false; 228 return result; 229 } finally { 230 Closeables.close(in, threw); 231 } 232 } 233 234 /** 235 * Returns a new {@link ByteArrayDataInput} instance to read from the {@code 236 * bytes} array from the beginning. 237 */ 238 public static ByteArrayDataInput newDataInput(byte[] bytes) { 239 return new ByteArrayDataInputStream(bytes); 240 } 241 242 /** 243 * Returns a new {@link ByteArrayDataInput} instance to read from the {@code 244 * bytes} array, starting at the given position. 245 * 246 * @throws IndexOutOfBoundsException if {@code start} is negative or greater 247 * than the length of the array 248 */ 249 public static ByteArrayDataInput newDataInput(byte[] bytes, int start) { 250 Preconditions.checkPositionIndex(start, bytes.length); 251 return new ByteArrayDataInputStream(bytes, start); 252 } 253 254 private static class ByteArrayDataInputStream implements ByteArrayDataInput { 255 final DataInput input; 256 257 ByteArrayDataInputStream(byte[] bytes) { 258 this.input = new DataInputStream(new ByteArrayInputStream(bytes)); 259 } 260 261 ByteArrayDataInputStream(byte[] bytes, int start) { 262 this.input = new DataInputStream( 263 new ByteArrayInputStream(bytes, start, bytes.length - start)); 264 } 265 266 @Override public void readFully(byte b[]) { 267 try { 268 input.readFully(b); 269 } catch (IOException e) { 270 throw new IllegalStateException(e); 271 } 272 } 273 274 @Override public void readFully(byte b[], int off, int len) { 275 try { 276 input.readFully(b, off, len); 277 } catch (IOException e) { 278 throw new IllegalStateException(e); 279 } 280 } 281 282 @Override public int skipBytes(int n) { 283 try { 284 return input.skipBytes(n); 285 } catch (IOException e) { 286 throw new IllegalStateException(e); 287 } 288 } 289 290 @Override public boolean readBoolean() { 291 try { 292 return input.readBoolean(); 293 } catch (IOException e) { 294 throw new IllegalStateException(e); 295 } 296 } 297 298 @Override public byte readByte() { 299 try { 300 return input.readByte(); 301 } catch (EOFException e) { 302 throw new IllegalStateException(e); 303 } catch (IOException impossible) { 304 throw new AssertionError(impossible); 305 } 306 } 307 308 @Override public int readUnsignedByte() { 309 try { 310 return input.readUnsignedByte(); 311 } catch (IOException e) { 312 throw new IllegalStateException(e); 313 } 314 } 315 316 @Override public short readShort() { 317 try { 318 return input.readShort(); 319 } catch (IOException e) { 320 throw new IllegalStateException(e); 321 } 322 } 323 324 @Override public int readUnsignedShort() { 325 try { 326 return input.readUnsignedShort(); 327 } catch (IOException e) { 328 throw new IllegalStateException(e); 329 } 330 } 331 332 @Override public char readChar() { 333 try { 334 return input.readChar(); 335 } catch (IOException e) { 336 throw new IllegalStateException(e); 337 } 338 } 339 340 @Override public int readInt() { 341 try { 342 return input.readInt(); 343 } catch (IOException e) { 344 throw new IllegalStateException(e); 345 } 346 } 347 348 @Override public long readLong() { 349 try { 350 return input.readLong(); 351 } catch (IOException e) { 352 throw new IllegalStateException(e); 353 } 354 } 355 356 @Override public float readFloat() { 357 try { 358 return input.readFloat(); 359 } catch (IOException e) { 360 throw new IllegalStateException(e); 361 } 362 } 363 364 @Override public double readDouble() { 365 try { 366 return input.readDouble(); 367 } catch (IOException e) { 368 throw new IllegalStateException(e); 369 } 370 } 371 372 @Override public String readLine() { 373 try { 374 return input.readLine(); 375 } catch (IOException e) { 376 throw new IllegalStateException(e); 377 } 378 } 379 380 @Override public String readUTF() { 381 try { 382 return input.readUTF(); 383 } catch (IOException e) { 384 throw new IllegalStateException(e); 385 } 386 } 387 } 388 389 /** 390 * Returns a new {@link ByteArrayDataOutput} instance with a default size. 391 */ 392 public static ByteArrayDataOutput newDataOutput() { 393 return new ByteArrayDataOutputStream(); 394 } 395 396 /** 397 * Returns a new {@link ByteArrayDataOutput} instance sized to hold 398 * {@code size} bytes before resizing. 399 * 400 * @throws IllegalArgumentException if {@code size} is negative 401 */ 402 public static ByteArrayDataOutput newDataOutput(int size) { 403 Preconditions.checkArgument(size >= 0, "Invalid size: %s", size); 404 return new ByteArrayDataOutputStream(size); 405 } 406 407 @SuppressWarnings("deprecation") // for writeBytes 408 private static class ByteArrayDataOutputStream 409 implements ByteArrayDataOutput { 410 411 final DataOutput output; 412 final ByteArrayOutputStream byteArrayOutputSteam; 413 414 ByteArrayDataOutputStream() { 415 this(new ByteArrayOutputStream()); 416 } 417 418 ByteArrayDataOutputStream(int size) { 419 this(new ByteArrayOutputStream(size)); 420 } 421 422 ByteArrayDataOutputStream(ByteArrayOutputStream byteArrayOutputSteam) { 423 this.byteArrayOutputSteam = byteArrayOutputSteam; 424 output = new DataOutputStream(byteArrayOutputSteam); 425 } 426 427 @Override public void write(int b) { 428 try { 429 output.write(b); 430 } catch (IOException impossible) { 431 throw new AssertionError(impossible); 432 } 433 } 434 435 @Override public void write(byte[] b) { 436 try { 437 output.write(b); 438 } catch (IOException impossible) { 439 throw new AssertionError(impossible); 440 } 441 } 442 443 @Override public void write(byte[] b, int off, int len) { 444 try { 445 output.write(b, off, len); 446 } catch (IOException impossible) { 447 throw new AssertionError(impossible); 448 } 449 } 450 451 @Override public void writeBoolean(boolean v) { 452 try { 453 output.writeBoolean(v); 454 } catch (IOException impossible) { 455 throw new AssertionError(impossible); 456 } 457 } 458 459 @Override public void writeByte(int v) { 460 try { 461 output.writeByte(v); 462 } catch (IOException impossible) { 463 throw new AssertionError(impossible); 464 } 465 } 466 467 @Override public void writeBytes(String s) { 468 try { 469 output.writeBytes(s); 470 } catch (IOException impossible) { 471 throw new AssertionError(impossible); 472 } 473 } 474 475 @Override public void writeChar(int v) { 476 try { 477 output.writeChar(v); 478 } catch (IOException impossible) { 479 throw new AssertionError(impossible); 480 } 481 } 482 483 @Override public void writeChars(String s) { 484 try { 485 output.writeChars(s); 486 } catch (IOException impossible) { 487 throw new AssertionError(impossible); 488 } 489 } 490 491 @Override public void writeDouble(double v) { 492 try { 493 output.writeDouble(v); 494 } catch (IOException impossible) { 495 throw new AssertionError(impossible); 496 } 497 } 498 499 @Override public void writeFloat(float v) { 500 try { 501 output.writeFloat(v); 502 } catch (IOException impossible) { 503 throw new AssertionError(impossible); 504 } 505 } 506 507 @Override public void writeInt(int v) { 508 try { 509 output.writeInt(v); 510 } catch (IOException impossible) { 511 throw new AssertionError(impossible); 512 } 513 } 514 515 @Override public void writeLong(long v) { 516 try { 517 output.writeLong(v); 518 } catch (IOException impossible) { 519 throw new AssertionError(impossible); 520 } 521 } 522 523 @Override public void writeShort(int v) { 524 try { 525 output.writeShort(v); 526 } catch (IOException impossible) { 527 throw new AssertionError(impossible); 528 } 529 } 530 531 @Override public void writeUTF(String s) { 532 try { 533 output.writeUTF(s); 534 } catch (IOException impossible) { 535 throw new AssertionError(impossible); 536 } 537 } 538 539 @Override public byte[] toByteArray() { 540 return byteArrayOutputSteam.toByteArray(); 541 } 542 543 } 544 545 // TODO(chrisn): Not all streams support skipping. 546 /** Returns the length of a supplied input stream, in bytes. */ 547 public static long length(InputSupplier<? extends InputStream> supplier) 548 throws IOException { 549 long count = 0; 550 boolean threw = true; 551 InputStream in = supplier.getInput(); 552 try { 553 while (true) { 554 // We skip only Integer.MAX_VALUE due to JDK overflow bugs. 555 long amt = in.skip(Integer.MAX_VALUE); 556 if (amt == 0) { 557 if (in.read() == -1) { 558 threw = false; 559 return count; 560 } 561 count++; 562 } else { 563 count += amt; 564 } 565 } 566 } finally { 567 Closeables.close(in, threw); 568 } 569 } 570 571 /** 572 * Returns true if the supplied input streams contain the same bytes. 573 * 574 * @throws IOException if an I/O error occurs 575 */ 576 public static boolean equal(InputSupplier<? extends InputStream> supplier1, 577 InputSupplier<? extends InputStream> supplier2) throws IOException { 578 byte[] buf1 = new byte[BUF_SIZE]; 579 byte[] buf2 = new byte[BUF_SIZE]; 580 581 boolean threw = true; 582 InputStream in1 = supplier1.getInput(); 583 try { 584 InputStream in2 = supplier2.getInput(); 585 try { 586 while (true) { 587 int read1 = read(in1, buf1, 0, BUF_SIZE); 588 int read2 = read(in2, buf2, 0, BUF_SIZE); 589 if (read1 != read2 || !Arrays.equals(buf1, buf2)) { 590 threw = false; 591 return false; 592 } else if (read1 != BUF_SIZE) { 593 threw = false; 594 return true; 595 } 596 } 597 } finally { 598 Closeables.close(in2, threw); 599 } 600 } finally { 601 Closeables.close(in1, threw); 602 } 603 } 604 605 /** 606 * Attempts to read enough bytes from the stream to fill the given byte array, 607 * with the same behavior as {@link DataInput#readFully(byte[])}. 608 * Does not close the stream. 609 * 610 * @param in the input stream to read from. 611 * @param b the buffer into which the data is read. 612 * @throws EOFException if this stream reaches the end before reading all 613 * the bytes. 614 * @throws IOException if an I/O error occurs. 615 */ 616 public static void readFully(InputStream in, byte[] b) throws IOException { 617 readFully(in, b, 0, b.length); 618 } 619 620 /** 621 * Attempts to read {@code len} bytes from the stream into the given array 622 * starting at {@code off}, with the same behavior as 623 * {@link DataInput#readFully(byte[], int, int)}. Does not close the 624 * stream. 625 * 626 * @param in the input stream to read from. 627 * @param b the buffer into which the data is read. 628 * @param off an int specifying the offset into the data. 629 * @param len an int specifying the number of bytes to read. 630 * @throws EOFException if this stream reaches the end before reading all 631 * the bytes. 632 * @throws IOException if an I/O error occurs. 633 */ 634 public static void readFully(InputStream in, byte[] b, int off, int len) 635 throws IOException { 636 if (read(in, b, off, len) != len) { 637 throw new EOFException(); 638 } 639 } 640 641 /** 642 * Discards {@code n} bytes of data from the input stream. This method 643 * will block until the full amount has been skipped. Does not close the 644 * stream. 645 * 646 * @param in the input stream to read from 647 * @param n the number of bytes to skip 648 * @throws EOFException if this stream reaches the end before skipping all 649 * the bytes 650 * @throws IOException if an I/O error occurs, or the stream does not 651 * support skipping 652 */ 653 public static void skipFully(InputStream in, long n) throws IOException { 654 while (n > 0) { 655 long amt = in.skip(n); 656 if (amt == 0) { 657 // Force a blocking read to avoid infinite loop 658 if (in.read() == -1) { 659 throw new EOFException(); 660 } 661 n--; 662 } else { 663 n -= amt; 664 } 665 } 666 } 667 668 /** 669 * Process the bytes of a supplied stream 670 * 671 * @param supplier the input stream factory 672 * @param processor the object to which to pass the bytes of the stream 673 * @return the result of the byte processor 674 * @throws IOException if an I/O error occurs 675 */ 676 public static <T> T readBytes(InputSupplier<? extends InputStream> supplier, 677 ByteProcessor<T> processor) throws IOException { 678 byte[] buf = new byte[BUF_SIZE]; 679 boolean threw = true; 680 InputStream in = supplier.getInput(); 681 try { 682 int amt; 683 do { 684 amt = in.read(buf); 685 if (amt == -1) { 686 threw = false; 687 break; 688 } 689 } while (processor.processBytes(buf, 0, amt)); 690 return processor.getResult(); 691 } finally { 692 Closeables.close(in, threw); 693 } 694 } 695 696 /** 697 * Computes and returns the checksum value for a supplied input stream. 698 * The checksum object is reset when this method returns successfully. 699 * 700 * @param supplier the input stream factory 701 * @param checksum the checksum object 702 * @return the result of {@link Checksum#getValue} after updating the 703 * checksum object with all of the bytes in the stream 704 * @throws IOException if an I/O error occurs 705 */ 706 public static long getChecksum(InputSupplier<? extends InputStream> supplier, 707 final Checksum checksum) throws IOException { 708 return readBytes(supplier, new ByteProcessor<Long>() { 709 @Override 710 public boolean processBytes(byte[] buf, int off, int len) { 711 checksum.update(buf, off, len); 712 return true; 713 } 714 715 @Override 716 public Long getResult() { 717 long result = checksum.getValue(); 718 checksum.reset(); 719 return result; 720 } 721 }); 722 } 723 724 /** 725 * Computes and returns the digest value for a supplied input stream. 726 * The digest object is reset when this method returns successfully. 727 * 728 * @param supplier the input stream factory 729 * @param md the digest object 730 * @return the result of {@link MessageDigest#digest()} after updating the 731 * digest object with all of the bytes in the stream 732 * @throws IOException if an I/O error occurs 733 */ 734 public static byte[] getDigest(InputSupplier<? extends InputStream> supplier, 735 final MessageDigest md) throws IOException { 736 return readBytes(supplier, new ByteProcessor<byte[]>() { 737 @Override 738 public boolean processBytes(byte[] buf, int off, int len) { 739 md.update(buf, off, len); 740 return true; 741 } 742 743 @Override 744 public byte[] getResult() { 745 return md.digest(); 746 } 747 }); 748 } 749 750 /** 751 * Reads some bytes from an input stream and stores them into the buffer array 752 * {@code b}. This method blocks until {@code len} bytes of input data have 753 * been read into the array, or end of file is detected. The number of bytes 754 * read is returned, possibly zero. Does not close the stream. 755 * 756 * <p>A caller can detect EOF if the number of bytes read is less than 757 * {@code len}. All subsequent calls on the same stream will return zero. 758 * 759 * <p>If {@code b} is null, a {@code NullPointerException} is thrown. If 760 * {@code off} is negative, or {@code len} is negative, or {@code off+len} is 761 * greater than the length of the array {@code b}, then an 762 * {@code IndexOutOfBoundsException} is thrown. If {@code len} is zero, then 763 * no bytes are read. Otherwise, the first byte read is stored into element 764 * {@code b[off]}, the next one into {@code b[off+1]}, and so on. The number 765 * of bytes read is, at most, equal to {@code len}. 766 * 767 * @param in the input stream to read from 768 * @param b the buffer into which the data is read 769 * @param off an int specifying the offset into the data 770 * @param len an int specifying the number of bytes to read 771 * @return the number of bytes read 772 * @throws IOException if an I/O error occurs 773 */ 774 public static int read(InputStream in, byte[] b, int off, int len) 775 throws IOException { 776 if (len < 0) { 777 throw new IndexOutOfBoundsException("len is negative"); 778 } 779 int total = 0; 780 while (total < len) { 781 int result = in.read(b, off + total, len - total); 782 if (result == -1) { 783 break; 784 } 785 total += result; 786 } 787 return total; 788 } 789 790 /** 791 * Returns an {@link InputSupplier} that returns input streams from the 792 * an underlying supplier, where each stream starts at the given 793 * offset and is limited to the specified number of bytes. 794 * 795 * @param supplier the supplier from which to get the raw streams 796 * @param offset the offset in bytes into the underlying stream where 797 * the returned streams will start 798 * @param length the maximum length of the returned streams 799 * @throws IllegalArgumentException if offset or length are negative 800 */ 801 public static InputSupplier<InputStream> slice( 802 final InputSupplier<? extends InputStream> supplier, 803 final long offset, 804 final long length) { 805 Preconditions.checkNotNull(supplier); 806 Preconditions.checkArgument(offset >= 0, "offset is negative"); 807 Preconditions.checkArgument(length >= 0, "length is negative"); 808 return new InputSupplier<InputStream>() { 809 @Override public InputStream getInput() throws IOException { 810 InputStream in = supplier.getInput(); 811 if (offset > 0) { 812 try { 813 skipFully(in, offset); 814 } catch (IOException e) { 815 Closeables.closeQuietly(in); 816 throw e; 817 } 818 } 819 return new LimitInputStream(in, length); 820 } 821 }; 822 } 823 824 /** 825 * Joins multiple {@link InputStream} suppliers into a single supplier. 826 * Streams returned from the supplier will contain the concatenated data from 827 * the streams of the underlying suppliers. 828 * 829 * <p>Only one underlying input stream will be open at a time. Closing the 830 * joined stream will close the open underlying stream. 831 * 832 * <p>Reading from the joined stream will throw a {@link NullPointerException} 833 * if any of the suppliers are null or return null. 834 * 835 * @param suppliers the suppliers to concatenate 836 * @return a supplier that will return a stream containing the concatenated 837 * stream data 838 */ 839 public static InputSupplier<InputStream> join( 840 final Iterable<? extends InputSupplier<? extends InputStream>> suppliers) { 841 return new InputSupplier<InputStream>() { 842 @Override public InputStream getInput() throws IOException { 843 return new MultiInputStream(suppliers.iterator()); 844 } 845 }; 846 } 847 848 /** Varargs form of {@link #join(Iterable)}. */ 849 public static InputSupplier<InputStream> join( 850 InputSupplier<? extends InputStream>... suppliers) { 851 return join(Arrays.asList(suppliers)); 852 } 853 }