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