1 /*

     2  * Copyright (c) 2009, 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 /**

    27  * IOUtils: A collection of IO-related public static methods.

    28  */

    29 

    30 package sun.misc;

    31 

    32 import java.io.EOFException;

    33 import java.io.IOException;

    34 import java.io.InputStream;

    35 import java.util.Arrays;

    36 

    37 public class IOUtils {

    38 

    39     /**

    40      * Read up to <code>length</code> of bytes from <code>in</code>

    41      * until EOF is detected.

    42      * @param is input stream, must not be null

    43      * @param length number of bytes to read, -1 or Integer.MAX_VALUE means

    44      *        read as much as possible

    45      * @param readAll if true, an EOFException will be thrown if not enough

    46      *        bytes are read. Ignored when length is -1 or Integer.MAX_VALUE

    47      * @return bytes read

    48      * @throws IOException Any IO error or a premature EOF is detected

    49      */

    50     public static byte[] readFully(InputStream is, int length, boolean readAll)

    51             throws IOException {

    52         byte[] output = {};

    53         if (length == -1) length = Integer.MAX_VALUE;

    54         int pos = 0;

    55         while (pos < length) {

    56             int bytesToRead;

    57             if (pos >= output.length) { // Only expand when there's no room

    58                 bytesToRead = Math.min(length - pos, output.length + 1024);

    59                 if (output.length < pos + bytesToRead) {

    60                     output = Arrays.copyOf(output, pos + bytesToRead);

    61                 }

    62             } else {

    63                 bytesToRead = output.length - pos;

    64             }

    65             int cc = is.read(output, pos, bytesToRead);

    66             if (cc < 0) {

    67                 if (readAll && length != Integer.MAX_VALUE) {

    68                     throw new EOFException("Detect premature EOF");

    69                 } else {

    70                     if (output.length != pos) {

    71                         output = Arrays.copyOf(output, pos);

    72                     }

    73                     break;

    74                 }

    75             }

    76             pos += cc;

    77         }

    78         return output;

    79     }

    80 }