1 /*
   2  * Copyright (c) 2000, 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  * @bug 4862411
  26  * @summary Test positional write method of FileChannel
  27  * @key randomness
  28  */
  29 
  30 import java.io.*;
  31 import java.nio.ByteBuffer;
  32 import java.nio.CharBuffer;
  33 import java.nio.channels.*;
  34 import java.nio.channels.FileChannel;
  35 import java.util.Random;
  36 
  37 
  38 /**
  39  * Testing FileChannel's positional write method.
  40  */
  41 public class Pwrite {
  42 
  43     private static Random generator = new Random();
  44 
  45     private static File blah;
  46 
  47     public static void main(String[] args) throws Exception {
  48         genericTest();
  49         testUnwritableChannel();
  50     }
  51 
  52     // This test for bug 4862411
  53     private static void testUnwritableChannel() throws Exception {
  54         File blah = File.createTempFile("blah2", null);
  55         blah.deleteOnExit();
  56         FileOutputStream fos = new FileOutputStream(blah);
  57         fos.write(new byte[128]);
  58         fos.close();
  59         FileInputStream fis = new FileInputStream(blah);
  60         FileChannel fc = fis.getChannel();
  61         try {
  62             fc.write(ByteBuffer.allocate(256),1);
  63             throw new RuntimeException("Expected exception not thrown");
  64         } catch(NonWritableChannelException e) {
  65             // Correct result
  66         } finally {
  67             fc.close();
  68             blah.delete();
  69         }
  70     }
  71 
  72     private static void genericTest() throws Exception {
  73         StringBuffer sb = new StringBuffer();
  74         sb.setLength(4);
  75 
  76         blah = File.createTempFile("blah", null);
  77         blah.deleteOnExit();
  78         initTestFile(blah);
  79 
  80         RandomAccessFile raf = new RandomAccessFile(blah, "rw");
  81         FileChannel c = raf.getChannel();
  82 
  83         for (int x=0; x<100; x++) {
  84             long offset = generator.nextInt(1000);
  85             ByteBuffer bleck = ByteBuffer.allocateDirect(4);
  86 
  87             // Write known sequence out
  88             for (byte i=0; i<4; i++) {
  89                 bleck.put(i);
  90             }
  91             bleck.flip();
  92             long originalPosition = c.position();
  93             int totalWritten = 0;
  94             while (totalWritten < 4) {
  95                 int written = c.write(bleck, offset);
  96                 if (written < 0)
  97                     throw new Exception("Read failed");
  98                 totalWritten += written;
  99             }
 100 
 101             long newPosition = c.position();
 102 
 103             // Ensure that file pointer position has not changed
 104             if (originalPosition != newPosition)
 105                 throw new Exception("File position modified");
 106 
 107             // Attempt to read sequence back in
 108             bleck = ByteBuffer.allocateDirect(4);
 109             originalPosition = c.position();
 110             int totalRead = 0;
 111             while (totalRead < 4) {
 112                 int read = c.read(bleck, offset);
 113                 if (read < 0)
 114                     throw new Exception("Read failed");
 115                 totalRead += read;
 116             }
 117             newPosition = c.position();
 118 
 119             // Ensure that file pointer position has not changed
 120             if (originalPosition != newPosition)
 121                 throw new Exception("File position modified");
 122 
 123             for (byte i=0; i<4; i++) {
 124                 if (bleck.get(i) != i)
 125                     throw new Exception("Write test failed");
 126             }
 127         }
 128         c.close();
 129         raf.close();
 130         blah.delete();
 131     }
 132 
 133     /**
 134      * Creates file blah:
 135      * 0000
 136      * 0001
 137      * 0002
 138      * 0003
 139      * .
 140      * .
 141      * .
 142      * 3999
 143      *
 144      * Blah extends beyond a single page of memory so that the
 145      * ability to index into a file of multiple pages is tested.
 146      */
 147     private static void initTestFile(File blah) throws Exception {
 148         FileOutputStream fos = new FileOutputStream(blah);
 149         BufferedWriter awriter
 150             = new BufferedWriter(new OutputStreamWriter(fos, "8859_1"));
 151 
 152         for(int i=0; i<4000; i++) {
 153             String number = new Integer(i).toString();
 154             for (int h=0; h<4-number.length(); h++)
 155                 awriter.write("0");
 156             awriter.write(""+i);
 157             awriter.newLine();
 158         }
 159        awriter.flush();
 160        awriter.close();
 161     }
 162 }
--- EOF ---