1 /*

     2  * Copyright (c) 1998, 2006, 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 4090383

    26    @summary Ensure that BufferedInputStream's read method will fill the target

    27             array whenever possible

    28  */

    29 

    30 

    31 import java.io.IOException;

    32 import java.io.InputStream;

    33 import java.io.BufferedInputStream;

    34 

    35 

    36 public class Fill {

    37 

    38     /**

    39      * A simple InputStream that is always ready but may read fewer than the

    40      * requested number of bytes

    41      */

    42     static class Source extends InputStream {

    43 

    44         int shortFall;

    45         byte next = 0;

    46 

    47         Source(int shortFall) {

    48             this.shortFall = shortFall;

    49         }

    50 

    51         public int read() throws IOException {

    52             return next++;

    53         }

    54 

    55         public int read(byte[] buf, int off, int len) throws IOException {

    56             int n = len - shortFall;

    57             for (int i = off; i < n; i++)

    58                 buf[i] = next++;

    59             return n;

    60         }

    61 

    62         public int available() {

    63             return Integer.MAX_VALUE;

    64         }

    65 

    66         public void close() throws IOException {

    67         }

    68 

    69     }

    70 

    71     /**

    72      * Test BufferedInputStream with an underlying source that always reads

    73      * shortFall fewer bytes than requested

    74      */

    75     static void go(int shortFall) throws Exception {

    76 

    77         InputStream r = new BufferedInputStream(new Source(shortFall), 10);

    78         byte[] buf = new byte[8];

    79 

    80         int n1 = r.read(buf);

    81         int n2 = r.read(buf);

    82         System.err.println("Shortfall " + shortFall

    83                            + ": Read " + n1 + ", then " + n2 + " bytes");

    84         if (n1 != buf.length)

    85             throw new Exception("First read returned " + n1);

    86         if (n2 != buf.length)

    87             throw new Exception("Second read returned " + n2);

    88 

    89     }

    90 

    91     public static void main(String[] args) throws Exception {

    92         for (int i = 0; i < 8; i++) go(i);

    93     }

    94 

    95 }