1 /* 2 * Copyright (c) 2015, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 24 import java.io.ByteArrayInputStream; 25 import java.io.IOException; 26 import java.io.InputStream; 27 import java.util.Arrays; 28 import java.util.Random; 29 30 /* 31 * @test 32 * @bug 8765432 33 * @library /lib/testlibrary 34 * @build jdk.testlibrary.* 35 * @key randomness 36 * @summary Basic test for InputStream.readNBytes 37 */ 38 public class ReadNBytes { 39 40 // TODO: Improve test coverage... 41 42 private static Random generator = RandomFactory.getRandom(); 43 44 public static void main(String[] args) throws IOException { 45 test(new byte[]{1, 2, 3}); 46 test(createRandomBytes(1024)); 47 test(createRandomBytes((1 << 13) - 1)); 48 test(createRandomBytes((1 << 13))); 49 test(createRandomBytes((1 << 13) + 1)); 50 test(createRandomBytes((1 << 15) - 1)); 51 test(createRandomBytes((1 << 15))); 52 test(createRandomBytes((1 << 15) + 1)); 53 test(createRandomBytes((1 << 17) - 1)); 54 test(createRandomBytes((1 << 17))); 55 test(createRandomBytes((1 << 17) + 1)); 56 } 57 58 static void test(byte[] inputBytes) throws IOException { 59 int length = inputBytes.length; 60 InputStream in = new ByteArrayInputStream(inputBytes); 61 byte[] readBytes = new byte[roundUp(length) >> 1]; 62 int nread = in.readNBytes(readBytes, 0, readBytes.length); 63 64 int x; 65 byte[] tmp; 66 check(nread == readBytes.length, 67 "Expected number of bytes read: " + readBytes.length + ", got: " + nread); 68 check(Arrays.equals((tmp = Arrays.copyOf(inputBytes, nread)), readBytes), 69 "Expected[" + tmp + "], got:[" + readBytes + "]"); 70 71 // Read again 72 nread = in.readNBytes(readBytes, 0, readBytes.length); 73 74 check(nread == length - readBytes.length, 75 "Expected number of bytes read: " + (length - readBytes.length) + ", got: " + nread); 76 check(Arrays.equals((tmp = Arrays.copyOfRange(inputBytes, readBytes.length, length)), 77 Arrays.copyOf(readBytes, nread)), 78 "Expected[" + tmp + "], got:[" + readBytes + "]"); 79 // Expect end of stream 80 check((x = in.read()) == -1, 81 "Expected end of stream from read(), got " + x); 82 check((x = in.read(tmp)) == -1, 83 "Expected end of stream from read(byte[]), got " + x); 84 check((x = in.read(tmp, 0, tmp.length)) == -1, 85 "Expected end of stream from read(byte[], int, int), got " + x); 86 check((x = in.readNBytes(tmp, 0, tmp.length)) == 0, 87 "Expected end of stream, 0, from readNBytes(byte[], int, int), got " + x); 88 } 89 90 static byte[] createRandomBytes(int size) { 91 byte[] bytes = new byte[size]; 92 generator.nextBytes(bytes); 93 return bytes; 94 } 95 96 private static int roundUp(int size) { 97 int x = Integer.highestOneBit(size); 98 if (x != size) 99 x = x << 1; 100 return x; 101 } 102 103 static void check(boolean cond, Object ... failedArgs) { 104 if (cond) 105 return; 106 StringBuilder sb = new StringBuilder(); 107 for (Object o : failedArgs) 108 sb.append(o); 109 throw new RuntimeException(sb.toString()); 110 } 111 }