1 /*
2  * Copyright (c) 2000, 2011, 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
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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
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22  */
23 
24 /* @test
25  * @bug 4429043 6526860
26  * @summary Test position method of FileChannel
27  * @key randomness
28  */
29 
30 import java.io.*;
31 import java.nio.ByteBuffer;
32 import java.nio.channels.FileChannel;
33 import java.nio.file.*;
34 import static java.nio.file.StandardOpenOption.*;
35 import java.nio.charset.Charset;
36 import java.util.Random;
37 
38 
39 /**
40  * Testing FileChannel's position method.
41  */
42 
43 public class Position {
44 
45     private static final Charset ISO8859_1 = Charset.forName("8859_1");
46 
47     private static final Random generator = new Random();
48 
main(String[] args)49     public static void main(String[] args) throws Exception {
50         Path blah = Files.createTempFile("blah", null);
51         blah.toFile().deleteOnExit();
52         initTestFile(blah);
53 
54         for (int i=0; i<10; i++) {
55             try (FileChannel fc = (generator.nextBoolean()) ?
56                     FileChannel.open(blah, READ) :
57                     new FileInputStream(blah.toFile()).getChannel()) {
58                 for (int j=0; j<100; j++) {
59                     long newPos = generator.nextInt(1000);
60                     fc.position(newPos);
61                     if (fc.position() != newPos)
62                         throw new RuntimeException("Position failed");
63                 }
64             }
65         }
66 
67         for (int i=0; i<10; i++) {
68             try (FileChannel fc = (generator.nextBoolean()) ?
69                      FileChannel.open(blah, APPEND) :
70                      new FileOutputStream(blah.toFile(), true).getChannel()) {
71                 for (int j=0; j<10; j++) {
72                     if (fc.position() != fc.size())
73                         throw new RuntimeException("Position expected to be size");
74                     byte[] buf = new byte[generator.nextInt(100)];
75                     fc.write(ByteBuffer.wrap(buf));
76                 }
77             }
78         }
79 
80         Files.delete(blah);
81     }
82 
83     /**
84      * Creates file blah:
85      * 0000
86      * 0001
87      * 0002
88      * 0003
89      * .
90      * .
91      * .
92      * 3999
93      *
94      */
initTestFile(Path blah)95     private static void initTestFile(Path blah) throws IOException {
96         try (BufferedWriter awriter = Files.newBufferedWriter(blah, ISO8859_1)) {
97             for(int i=0; i<4000; i++) {
98                 String number = new Integer(i).toString();
99                 for (int h=0; h<4-number.length(); h++)
100                     awriter.write("0");
101                 awriter.write(""+i);
102                 awriter.newLine();
103             }
104         }
105     }
106 }
107