1 /* 2 * Copyright (c) 1997, 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 4085938 26 @summary Check for the correct behaviour of DataInputStream.skipBytes 27 */ 28 29 import java.io.*; 30 31 public class SkipBytes{ 32 dotest(DataInputStream dis, int pos, int total, int toskip, int expected)33 private static void dotest(DataInputStream dis, int pos, int total, 34 int toskip, int expected) { 35 36 try { 37 System.err.println("\n\nTotal bytes in the stream = " + total); 38 System.err.println("Currently at position = " + pos); 39 System.err.println("Bytes to skip = " + toskip); 40 System.err.println("Expected result = " + expected); 41 int skipped = dis.skipBytes(toskip); 42 System.err.println("Actual skipped = " + skipped); 43 if (skipped != expected) { 44 throw new RuntimeException 45 ("DataInputStream.skipBytes does not return expected value"); 46 } 47 } catch(EOFException e){ 48 throw new RuntimeException 49 ("DataInputStream.skipBytes throws unexpected EOFException"); 50 } catch (IOException e) { 51 System.err.println("IOException is thrown - possible result"); 52 } 53 54 55 } 56 57 58 main(String args[])59 public static void main(String args[]) throws Exception { 60 61 DataInputStream dis = new DataInputStream(new MyInputStream()); 62 dotest(dis, 0, 11, -1, 0); 63 dotest(dis, 0, 11, 5, 5); 64 System.err.println("\n***CAUTION**** - may go into an infinite loop"); 65 dotest(dis, 5, 11, 20, 6); 66 } 67 } 68 69 70 class MyInputStream extends InputStream { 71 72 private int readctr = 0; 73 read()74 public int read() { 75 76 if (readctr > 10){ 77 return -1; 78 } 79 else{ 80 readctr++; 81 return 0; 82 } 83 84 } 85 available()86 public int available() { return 0; } 87 } 88