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 

    25 /* @test

    26    @bug 4085939

    27    @summary Check for the correct behaviour of LineNumberInputStream.skip

    28    */

    29 

    30 import java.io.*;

    31 

    32 

    33 public class Skip{

    34 

    35     private static void dotest(LineNumberInputStream in , int curpos ,

    36                                long total , long toskip , long expected)

    37         throws Exception

    38     {

    39 

    40         try {

    41 

    42             System.err.println("\n\nCurrently at pos = " + curpos +

    43                                "\nTotal bytes in the Stream = " + total +

    44                                "\nNumber of bytes to skip = " + toskip +

    45                                "\nNumber of bytes that should be skipped = " +

    46                                expected);

    47 

    48             long skipped = in.skip(toskip);

    49 

    50             System.err.println("actual number skipped: "+ skipped);

    51 

    52             if ((skipped < 0) || (skipped > expected)) {

    53                 throw new RuntimeException("Unexpected number of bytes skipped");

    54             }

    55 

    56         } catch (IOException e) {

    57             System.err.println("IOException is thrown - possible result");

    58         } catch (Throwable e) {

    59             throw new RuntimeException("Unexpected "+e+" is thrown!");

    60         }

    61 

    62     }

    63 

    64     public static void main( String argv[] ) throws Exception {

    65 

    66         LineNumberInputStream in = new LineNumberInputStream(new MyInputStream(11));

    67 

    68         /* test for negative skip */

    69         dotest(in,  0, 11, -23,  0);

    70 

    71         /* check for skip beyond EOF starting from before EOF */

    72         dotest(in,  0, 11,  20, 11);

    73 

    74         /* check for skip after EOF */

    75         dotest(in, -1, 11,  20,  0);

    76 

    77     }

    78 

    79 }

    80 

    81 class MyInputStream extends InputStream {

    82 

    83     private int readctr = 0;

    84     private long endoffile;

    85 

    86     public MyInputStream(long endoffile) {

    87         this.endoffile = endoffile;

    88     }

    89 

    90     public int read() {

    91 

    92         if (readctr == endoffile) {

    93             return -1;

    94         }

    95         else {

    96             readctr++;

    97             return 0;

    98         }

    99     }

   100 

   101     public int available() { return 0; }

   102 }