Hi > What version tomcat?
I see this under 6.0.29 [and I think under 6.0.18 before, but I am not
sure], but as this is pure java code, not calling any tomcat code and not
probably affected by tomcat code, I don't think that matters. (That's why I
labeled that off-topic.)
However, if it even could be of any help solving this mystery, I will
provide any information needed.
Regards,
Steffen
>
>
> On Mon, Aug 30, 2010 at 3:38 PM, Steffen Heil <li...@steffen-heil.de>
wrote:
>
> > Hi
> >
> > I am sorry, I am asking something not really related to tomcat here.
> > While this may sound like a beginners question, I think I really what
> > I am doing in java, but this time I suspect I have found a scenario
> > where the sun/oracle VM exposes a bug with pure String handling.
> >
> > So anyone who can find a bug in the procedure posted below is very
> welcome.
> > So is everyone who can direct me to some place better suited to ask
> > this question.
> >
> > Finding bugs in a static method that only takes immutable arguments
> > usually seems easy... Turns out, it is not.
> >
> > However, please note that I already tried to debug this in various
> > ways and the exception does NOT occur, as soon as a debugger is
> > attached. The exception is only thrown under 64bit Linux Server-VM,
> > within tomcat. It is neither thrown under 64bit Windows, nor on the
> > very same Linux VM as standalone testcase, nor when a debugger is
> > remotely attached. The JREs testest are 1.6u20 and 1.6u21.
> >
> > The code in question is the following:
> >
> >
> > @SuppressWarnings( "null" )
> > public final static String replaceAll( String stack, String ...
> > replacements )
> > {
> > try {
> > if ( stack == null )
> > return stack;
> > int index, pos;
> > String niddle = null, string;
> > int niddleLength, stringLength;
> > for ( index = 0; true; index += 2 ) {
> > if ( index >= replacements.length )
> > return stack;
> > niddle = replacements[ index ];
> > pos = stack.indexOf( niddle );
> > if ( pos != - 1 )
> > break;
> > }
> > StringBuilder buffer = new StringBuilder( stack
);
> > niddleLength = niddle.length();
> > string = replacements[ index + 1 ];
> > if ( string == null )
> > do
> > buffer.delete( pos, pos +
> > niddleLength );
> > while ( ( pos = buffer.indexOf( niddle,
> > pos
> > ) ) != - 1 );
> > else {
> > stringLength = string.length();
> > do {
> > /*331*/ buffer.replace( pos, pos + niddleLength,
> > string );
> > pos += stringLength;
> > } while ( ( pos = buffer.indexOf(
> > niddle, pos ) ) != - 1 );
> > }
> > index += 2;
> > for ( ; index < replacements.length; index += 2 )
{
> > niddle = replacements[ index ];
> > string = replacements[ index + 1 ];
> > niddleLength = niddle.length();
> > if ( string == null )
> > for ( pos = 0; ( pos =
> > buffer.indexOf( niddle, pos ) ) != - 1; )
> > buffer.delete( pos, pos
> > + niddleLength );
> > else {
> > stringLength = string.length();
> > for ( pos = 0; ( pos =
> > buffer.indexOf( niddle, pos ) ) != - 1; pos += stringLength )
> > buffer.replace( pos,
> > pos + niddleLength, string );
> > }
> > }
> > return buffer.toString();
> > } catch ( Throwable t ) { .... (code to dump the
> > arguments and the stack trace) ...
> > }
> > }
> >
> >
> > Note, that when the method is called, there are two arguments: one
> > String and a String[] with a length of 1004 Strings.... (I guarantee
> > that this String array is NOT modified during execution, not even
> > afterwards.) The execption is (it is thrown indirectly in the marked
line 331):
> >
> > java.lang.StringIndexOutOfBoundsException: start > length()
> > at
> > java.lang.AbstractStringBuilder.replace(AbstractStringBuilder.java:799)
> > at java.lang.StringBuilder.replace(StringBuilder.java:271)
> > at
> > com.osiris4.core.utils.StringUtils.replaceAll(StringUtils.java:331)
> > ....
> >
> >
> > I can provide real arguments that lead to this exception, however, as
> > there are more than 1000 Strings (partially large ones) involved, I
> > will skip them here.
> > Anyone interested will get them by mail. I have various samples.
> >
> >
> > Currently this prevents loading my web application in about one of
> > three times. (And it also happens during internal computations which
> > prevents further work.) Sometimes this error can be "reproduced" (by
> > restarting
> > tomcat) 10 times in a row, sometimes it does not occur within 20
> > restarts at all. (Without changing anything in the systems
> > configuration.)
> >
> >
> > Sorry again, for asking off-topic, but I don't know where to ask for
> > help anymore.
> >
> > Regards,
> > Steffen
> >
> >
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