| /* |
| * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /* |
| * @test |
| * @bug 8010837 8011136 |
| * @summary Test if available returns correct value when skipping beyond |
| * the end of a file. |
| * @author Dan Xu |
| */ |
| |
| import java.io.BufferedWriter; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.nio.charset.Charset; |
| import java.nio.file.Files; |
| import java.nio.file.Path; |
| |
| public class NegativeAvailable { |
| |
| public static void main(String[] args) throws IOException { |
| final int SIZE = 10; |
| final int SKIP = 5; |
| final int NEGATIVE_SKIP = -5; |
| |
| // Create a temporary file with size of 10 bytes. |
| Path tmp = Files.createTempFile(null, null); |
| try (BufferedWriter writer = |
| Files.newBufferedWriter(tmp, Charset.defaultCharset())) { |
| for (int i = 0; i < SIZE; i++) { |
| writer.write('1'); |
| } |
| } |
| |
| File tempFile = tmp.toFile(); |
| try (FileInputStream fis = new FileInputStream(tempFile)) { |
| if (tempFile.length() != SIZE) { |
| throw new RuntimeException("unexpected file size = " |
| + tempFile.length()); |
| } |
| long space = skipBytes(fis, SKIP, SIZE); |
| space = skipBytes(fis, NEGATIVE_SKIP, space); |
| space = skipBytes(fis, SKIP, space); |
| space = skipBytes(fis, SKIP, space); |
| space = skipBytes(fis, SKIP, space); |
| space = skipBytes(fis, NEGATIVE_SKIP, space); |
| space = skipBytes(fis, NEGATIVE_SKIP, space); |
| } |
| Files.deleteIfExists(tmp); |
| } |
| |
| /** |
| * Skip toSkip number of bytes and return the remaining bytes of the file. |
| */ |
| private static long skipBytes(FileInputStream fis, int toSkip, long space) |
| throws IOException { |
| long skip = fis.skip(toSkip); |
| if (skip != toSkip) { |
| throw new RuntimeException("skip() returns " + skip |
| + " but expected " + toSkip); |
| } |
| long newSpace = space - toSkip; |
| long remaining = newSpace > 0 ? newSpace : 0; |
| int avail = fis.available(); |
| if (avail != remaining) { |
| throw new RuntimeException("available() returns " + avail |
| + " but expected " + remaining); |
| } |
| |
| System.out.println("Skipped " + skip + " bytes " |
| + " available() returns " + avail); |
| return newSpace; |
| } |
| } |