Name: nt126004 Date: 01/04/2002


FULL PRODUCT VERSION :
java version "1.4.0-beta3"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.4.0-beta3-b84)
Java HotSpot(TM) Client VM (build 1.4.0-beta3-b84, mixed mode)

A DESCRIPTION OF THE PROBLEM :
The following code throw an IndexOutOfBoundsException.

import java.util.regex.*;
import java.io.*;
import java.nio.*;
import java.nio.charset.*;
import java.nio.channels.*;

public class CharBufferExample {
public static void main(String[] args) throws Exception {
// Create a pattern to match comments
Pattern p = Pattern.compile("//.*$", Pattern.MULTILINE);

// Get a Channel for the source file
File f = new File("Replacement.java");
FileInputStream fis = new FileInputStream(f);
FileChannel fc = fis.getChannel();

// Get a CharBuffer from the source file
ByteBuffer bb = fc.map(FileChannel.MapMode.READ_ONLY, 0, (int)fc.size());
Charset cs = Charset.forName("8859_1");
CharsetDecoder cd = cs.newDecoder();
CharBuffer cb = cd.decode(bb);

// Run some matches
Matcher m = p.matcher(cb);
while (m.find()) {
System.out.println("Found comment: " + m.group());
}
}
}

But if the line 24 was changed by:

Matcher m = p.matcher(cb.toString());

then it works fine.

ERROR MESSAGES/STACK TRACES THAT OCCUR :
Exception in thread "main"
java.lang.IndexOutOfBoundsException
        at java.nio.Buffer.checkIndex(Buffer.java:417)
        at java.nio.CharBuffer.charAt(CharBuffer.java:1108)
        at java.util.regex.Pattern$Slice.match(Pattern.java:3097)
        at java.util.regex.Pattern$Start.match(Pattern.java:2660)
        at java.util.regex.Matcher.find(Matcher.java:690)
        at java.util.regex.Matcher.find(Matcher.java:407)
        at CharBufferExample.main(CharBufferExample.java:25)

This bug can be reproduced always.
(Review ID: 137519)
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