1 /*

     2  * Copyright 1998 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,

    20  * CA 95054 USA or visit www.sun.com if you need additional information or

    21  * have any questions.

    22  */

    23 

    24 /* @test

    25    @bug 4090383

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

    27             whenever possible

    28  */

    29 

    30 

    31 import java.io.IOException;

    32 import java.io.Reader;

    33 import java.io.BufferedReader;

    34 

    35 

    36 public class Fill {

    37 

    38     /**

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

    40      * requested number of characters

    41      */

    42     static class Source extends Reader {

    43 

    44         int shortFall;

    45         char next = 0;

    46 

    47         Source(int shortFall) {

    48             this.shortFall = shortFall;

    49         }

    50 

    51         public int read(char[] cbuf, int off, int len) throws IOException {

    52             int n = len - shortFall;

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

    54                 cbuf[i] = next++;

    55             return n;

    56         }

    57 

    58         public boolean ready() {

    59             return true;

    60         }

    61 

    62         public void close() throws IOException {

    63         }

    64 

    65     }

    66 

    67     /**

    68      * Test BufferedReader with an underlying source that always reads

    69      * shortFall fewer characters than requested

    70      */

    71     static void go(int shortFall) throws Exception {

    72 

    73         Reader r = new BufferedReader(new Source(shortFall), 10);

    74         char[] cbuf = new char[8];

    75 

    76         int n1 = r.read(cbuf);

    77         int n2 = r.read(cbuf);

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

    79                            + ": Read " + n1 + ", then " + n2 + " chars");

    80         if (n1 != cbuf.length)

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

    82         if (n2 != cbuf.length)

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

    84 

    85     }

    86 

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

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

    89     }

    90 

    91 }