1 /* 2 * Copyright (c) 2009, 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 /** 27 * IOUtils: A collection of IO-related public static methods. 28 */ 29 30 package sun.security.util; 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 44 * @param readAll if true, an EOFException will be thrown if not enough 45 * bytes are read. 46 * @return bytes read 47 * @throws IOException Any IO error or a premature EOF is detected 48 */ 49 public static byte[] readFully(InputStream is, int length, boolean readAll) 50 throws IOException { 51 if (length < 0) { 52 throw new IndexOutOfBoundsException(); 53 } 54 byte[] output = {}; 55 int pos = 0; 56 while (pos < length) { 57 int bytesToRead; 58 if (pos >= output.length) { // Only expand when there's no room 59 bytesToRead = Math.min(length - pos, output.length + 1024); 60 if (output.length < pos + bytesToRead) { 61 output = Arrays.copyOf(output, pos + bytesToRead); 62 } 63 } else { 64 bytesToRead = output.length - pos; 65 } 66 int cc = is.read(output, pos, bytesToRead); 67 if (cc < 0) { 68 if (readAll) { 69 throw new EOFException("Detect premature EOF"); 70 } else { 71 if (output.length != pos) { 72 output = Arrays.copyOf(output, pos); 73 } 74 break; 75 } 76 } 77 pos += cc; 78 } 79 return output; 80 } 81 }