1 /* 2 * Copyright (c) 2013, 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 /* 25 * @test 26 * @bug 8010837 27 * @summary Test if available returns correct value when skipping beyong 28 * the end of a file. 29 * @author Dan Xu 30 */ 31 32 import java.io.BufferedWriter; 33 import java.io.File; 34 import java.io.FileInputStream; 35 import java.io.IOException; 36 import java.nio.charset.Charset; 37 import java.nio.file.Files; 38 import java.nio.file.Path; 39 40 public class NegativeAvailable { 41 42 public static void main(String[] args) throws IOException { 43 final int SIZE = 10; 44 final int SKIP = 5; 45 46 // Create a temporary file with size of 10 bytes. 47 Path tmp = Files.createTempFile(null, null); 48 try (BufferedWriter writer = 49 Files.newBufferedWriter(tmp, Charset.defaultCharset())) { 50 for (int i = 0; i < SIZE; i++) { 51 writer.write('1'); 52 } 53 } 54 55 File tempFile = tmp.toFile(); 56 try (FileInputStream fis = new FileInputStream(tempFile)) { 57 if (tempFile.length() != SIZE) { 58 throw new RuntimeException("unexpected file size = " 59 + tempFile.length()); 60 } 61 long space = skipBytes(fis, SKIP, SIZE); 62 space = skipBytes(fis, SKIP, space); 63 space = skipBytes(fis, SKIP, space); 64 space = skipBytes(fis, SKIP, space); 65 } 66 Files.deleteIfExists(tmp); 67 } 68 69 /** 70 * Skip toSkip number of bytes and return the remaining bytes of the file. 71 */ 72 private static long skipBytes(FileInputStream fis, int toSkip, long space) 73 throws IOException { 74 long skip = fis.skip(toSkip); 75 if (skip != toSkip) { 76 throw new RuntimeException("skip() returns " + skip 77 + " but expected " + toSkip); 78 } 79 long remaining = space - toSkip; 80 int avail = fis.available(); 81 if (avail != remaining) { 82 throw new RuntimeException("available() returns " + avail 83 + " but expected " + remaining); 84 } 85 86 System.out.println("Skipped " + skip + " bytes " 87 + " available() returns " + avail); 88 return remaining; 89 } 90 }