1 /* 2 * Copyright (c) 2000, 2011, 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 /* @test 25 * @bug 6191269 6709457 26 * @summary Test truncate method of FileChannel 27 */ 28 29 import java.io.*; 30 import java.nio.ByteBuffer; 31 import java.nio.channels.FileChannel; 32 import static java.nio.file.StandardOpenOption.*; 33 import java.util.Random; 34 35 36 /** 37 * Testing FileChannel's truncate method. 38 */ 39 40 public class Truncate { 41 private static final Random generator = new Random(); 42 43 public static void main(String[] args) throws Exception { 44 File blah = File.createTempFile("blah", null); 45 blah.deleteOnExit(); 46 try { 47 basicTest(blah); 48 appendTest(blah); 49 } finally { 50 blah.delete(); 51 } 52 } 53 54 /** 55 * Basic test of asserts in truncate's specification. 56 */ 57 static void basicTest(File blah) throws Exception { 58 for(int i=0; i<100; i++) { 59 long testSize = generator.nextInt(1000) + 10; 60 initTestFile(blah, testSize); 61 62 try (FileChannel fc = (i < 50) ? 63 new RandomAccessFile(blah, "rw").getChannel() : 64 FileChannel.open(blah.toPath(), READ, WRITE)) 65 { 66 if (fc.size() != testSize) 67 throw new RuntimeException("Size failed"); 68 69 long position = generator.nextInt((int)testSize); 70 fc.position(position); 71 72 long newSize = generator.nextInt((int)testSize); 73 fc.truncate(newSize); 74 75 if (fc.size() != newSize) 76 throw new RuntimeException("Truncate failed"); 77 78 if (position > newSize) { 79 if (fc.position() != newSize) 80 throw new RuntimeException("Position greater than size"); 81 } else { 82 if (fc.position() != position) 83 throw new RuntimeException("Truncate changed position"); 84 }; 85 } 86 } 87 } 88 89 /** 90 * Test behavior of truncate method when file is opened for append 91 */ 92 static void appendTest(File blah) throws Exception { 93 for (int i=0; i<10; i++) { 94 long testSize = generator.nextInt(1000) + 10; 95 initTestFile(blah, testSize); 96 try (FileChannel fc = (i < 5) ? 97 new FileOutputStream(blah, true).getChannel() : 98 FileChannel.open(blah.toPath(), APPEND)) 99 { 100 // truncate file 101 long newSize = generator.nextInt((int)testSize); 102 fc.truncate(newSize); 103 if (fc.size() != newSize) 104 throw new RuntimeException("Truncate failed"); 105 106 // write one byte 107 ByteBuffer buf = ByteBuffer.allocate(1); 108 buf.put((byte)'x'); 109 buf.flip(); 110 fc.write(buf); 111 if (fc.size() != (newSize+1)) 112 throw new RuntimeException("Unexpected size"); 113 } 114 } 115 } 116 117 /** 118 * Creates file blah of specified size in bytes. 119 * 120 */ 121 private static void initTestFile(File blah, long size) throws Exception { 122 if (blah.exists()) 123 blah.delete(); 124 FileOutputStream fos = new FileOutputStream(blah); 125 BufferedWriter awriter 126 = new BufferedWriter(new OutputStreamWriter(fos, "8859_1")); 127 128 for(int i=0; i<size; i++) { 129 awriter.write("e"); 130 } 131 awriter.flush(); 132 awriter.close(); 133 } 134 }