1/*
2 * Copyright (c) 2010, 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 * @summary Ensure that InputStreamReader reads as many characters as possible
26 */
27
28// InputStreamReader is not required by its spec to read as many characters as
29// possible upon each invocation of read(char[], int, int), but many programs
30// (e.g., javac) depend upon this behavior.
31
32import java.io.*;
33
34
35public class FullRead {
36
37    static int MAX_LEN = 1 << 16;
38
39    static void test(File f, int len) throws Exception {
40        FileOutputStream fo = new FileOutputStream(f);
41        for (int i = 0; i < len; i++)
42            fo.write('x');
43        fo.close();
44
45        FileInputStream fi = new FileInputStream(f);
46        Reader rd = new InputStreamReader(fi, "US-ASCII");
47        char[] cb = new char[MAX_LEN + 100];
48        int n = rd.read(cb, 0, cb.length);
49        System.out.println(len + " : " + n);
50        if (len != n)
51            throw new Exception("Expected " + len + ", read " + n);
52    }
53
54    public static void main(String[] args) throws Exception {
55        File f = File.createTempFile("foo", "bar");
56        f.deleteOnExit();
57        System.out.println(f);
58
59        for (int i = 4; i <= MAX_LEN; i <<= 1)
60            test(f, i);
61    }
62
63}
64