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 4862382 4862408
  26  * @summary Test positional read 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 read method.
  39  */
  40 
  41 public class Pread {
  42 
  43     private static PrintStream err = System.err;
  44 
  45     private static Random generator = new Random();
  46 
  47     private static int CHARS_PER_LINE = File.separatorChar == '/' ? 5 : 6;
  48 
  49     public static void main(String[] args) throws Exception {
  50         genericTest();
  51         testNegativePosition(); // This test for bug 4862382
  52         testUnreadableChannel();// This test for bug 4862408
  53     }
  54 
  55     // This test for bug 4862382
  56     private static void testNegativePosition() throws Exception {
  57         File blah = File.createTempFile("blah1", null);
  58         blah.deleteOnExit();
  59         FileOutputStream fos = new FileOutputStream(blah);
  60         fos.write(new byte[128]);
  61         fos.close();
  62         FileChannel fc = (new FileInputStream(blah)).getChannel();
  63         try {
  64             fc.read(ByteBuffer.allocate(256), -1L);
  65             throw new RuntimeException("Expected exception not thrown");
  66         } catch(IllegalArgumentException e) {
  67             // Correct result
  68         } finally {
  69             fc.close();
  70             blah.delete();
  71         }
  72     }
  73 
  74     // This test for bug 4862408
  75     private static void testUnreadableChannel() throws Exception {
  76         File blah = File.createTempFile("blah2", null);
  77         blah.deleteOnExit();
  78         FileOutputStream fos = new FileOutputStream(blah);
  79         try {
  80             fos.write(new byte[128]);
  81             FileChannel fc = fos.getChannel();
  82             try {
  83                 fc.read(ByteBuffer.allocate(256),1);
  84                 throw new RuntimeException("Expected exception not thrown");
  85             } catch(NonReadableChannelException e) {
  86                 // Correct result
  87             }
  88         } finally {
  89             fos.close();
  90             blah.delete();
  91         }
  92     }
  93 
  94     private static void genericTest() throws Exception {
  95         StringBuffer sb = new StringBuffer();
  96         sb.setLength(4);
  97 
  98         File blah = File.createTempFile("blah3", null);
  99         blah.deleteOnExit();
 100         initTestFile(blah);
 101 
 102         FileInputStream fis = new FileInputStream(blah);
 103         FileChannel c = fis.getChannel();
 104 
 105         for (int x=0; x<100; x++) {
 106             long offset = generator.nextInt(1000);
 107             long expectedResult = offset / CHARS_PER_LINE;
 108             offset = expectedResult * CHARS_PER_LINE;
 109             ByteBuffer bleck = ByteBuffer.allocateDirect(4);
 110 
 111             long originalPosition = c.position();
 112 
 113             int totalRead = 0;
 114             while (totalRead < 4) {
 115                 int read = c.read(bleck, offset);
 116                 if (read < 0)
 117                     throw new Exception("Read failed");
 118                 totalRead += read;
 119             }
 120 
 121             long newPosition = c.position();
 122 
 123             for (int i=0; i<4; i++) {
 124                 byte aByte = bleck.get(i);
 125                 sb.setCharAt(i, (char)aByte);
 126             }
 127             int result = Integer.parseInt(sb.toString());
 128             if (result != expectedResult) {
 129                 err.println("I expected "+ expectedResult);
 130                 err.println("I got "+ result);
 131                 throw new Exception("Read test failed");
 132             }
 133 
 134             // Ensure that file pointer position has not changed
 135             if (originalPosition != newPosition)
 136                 throw new Exception("File position modified");
 137         }
 138 
 139         c.close();
 140         fis.close();
 141         blah.delete();
 142     }
 143 
 144     /**
 145      * Creates file blah:
 146      * 0000
 147      * 0001
 148      * 0002
 149      * 0003
 150      * .
 151      * .
 152      * .
 153      * 3999
 154      *
 155      * Blah extends beyond a single page of memory so that the
 156      * ability to index into a file of multiple pages is tested.
 157      */
 158     private static void initTestFile(File blah) throws Exception {
 159         FileOutputStream fos = new FileOutputStream(blah);
 160         BufferedWriter awriter
 161             = new BufferedWriter(new OutputStreamWriter(fos, "8859_1"));
 162 
 163         for(int i=0; i<4000; i++) {
 164             String number = new Integer(i).toString();
 165             for (int h=0; h<4-number.length(); h++)
 166                 awriter.write("0");
 167             awriter.write(""+i);
 168             awriter.newLine();
 169         }
 170        awriter.flush();
 171        awriter.close();
 172     }
 173 }