XML4j issue

[Frank Lee <Fr...@redflex.com.au>]

Hello,

Our project is based on jdk1.4.2 and run on WebSphere v5.1. As some of our codes has existed for more than 6 years, the xml parser has not been updated since it was first used (Version: XML4j 4.0.9). It does the job until recently two of new business processes was implemented. Both functions (one of them uses crystal report java library) use SAXParser, and three kinds of exceptions occur:
Firstly, a ClassDefNotFound Exception is thrown by crystal report library. We are still trying to drill down the root cause.
Second, a ClassCastException. We are aware that it may have something to do with websphere class loader.
Lastly, serious memory leaking that causes system crash.

The first two exceptions occur very rarely, plus we are not sure about the root causes, it's very difficult to reproduce exception. We doubt that early version of XML4j may has some issues with multi-threading (so exception may rise when few functions try to access parser at same time).

After research online, we know it has been reported that early version of SAXParsers do have memory leaking issue. We are not sure if that include version XML4j 4.0.9.

We understand it's better to download the latest version of Xerces.jar. However, we are concerned about the impact on the existing old codes if we use the new version. Hence, we decide to identify the problem first.

Any advice will be much appreciated. Thank you.

Kind Regards,

Frank


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Re: XML4j issue

[Michael Glavassevich <mr...@ca.ibm.com>]

Hi Frank,

As you probably realized when you subscribed, the purpose of this mailing
list is for discussion of Apache Xerces-J (i.e. the open source version).
Your question relates more to usage of the IBM derivative (XML4J) in
WebSphere and would encourage you to go through a more appropriate support
channel [1] for assistance.

Thanks.

[1] http://www-01.ibm.com/software/webservers/appserv/was/support/

Michael Glavassevich
XML Parser Development
IBM Toronto Lab
E-mail: mrglavas@ca.ibm.com
E-mail: mrglavas@apache.org

Frank Lee <Fr...@redflex.com.au> wrote on 06/12/2009 03:12:30 AM:

> Hello,
>
> Our project is based on jdk1.4.2 and run on WebSphere v5.1. As some
> of our codes has existed for more than 6 years, the xml parser has
> not been updated since it was first used (Version: XML4j 4.0.9). It
> does the job until recently two of new business processes was
> implemented. Both functions (one of them uses crystal report java
> library) use SAXParser, and three kinds of exceptions occur:
> Firstly, a ClassDefNotFound Exception is thrown by crystal report
> library. We are still trying to drill down the root cause.
> Second, a ClassCastException. We are aware that it may have
> something to do with websphere class loader.
> Lastly, serious memory leaking that causes system crash.
>
> The first two exceptions occur very rarely, plus we are not sure
> about the root causes, it?s very difficult to reproduce exception.
> We doubt that early version of XML4j may has some issues with multi-
> threading (so exception may rise when few functions try to access
> parser at same time).
>
> After research online, we know it has been reported that early
> version of SAXParsers do have memory leaking issue. We are not sure
> if that include version XML4j 4.0.9.
>
> We understand it?s better to download the latest version of Xerces.
> jar. However, we are concerned about the impact on the existing old
> codes if we use the new version. Hence, we decide to identify the
> problem first.
>
> Any advice will be much appreciated. Thank you.
>
> Kind Regards,
>
> Frank