Experiences with Adobe XPAAJ, XML Parsers, OC4J /AS 10.1.2,10.1.3 and DB10g

Question

Over the past couple of weeks we have been working on a solution which uses the newly available adobe XPAAJ api's (XML/PDF Access API for Java) for Java.
The client has a legacy requirement to where users are issued with a pdf form which they complete, save and upload to the server via a JSP. A neat bit of Java code utilizing the XPAAJ API's then strips out the form entered data and spits out XML. This is then parsed and inserted into relational tables within the schema.
Our solution needs to be deployed to an Oracle stack. However we ran into a number of problems when deploying the solution to AS 10.1.2. The adobe API's are not compatible with the Oracle XML Parsers. When extracting the form data, no error is reported and the code which performs the xml parsing just fails. Very nasty.
The main problem has been that Oracle XDK libraries have been hard-coded into the classpath of the container using the referential JAR file Class-Path mechanism. Altering this has required the use of the JRE extension library mechanism, or altering the boot classpath of the JVM when it is launched to load the alternative XML parser implementation instead. While this works, it has been an unsupported operation since the effect of this change is not limited to a specific application – it’s effect are felt across the entire container and this may lead to unpredictable results at runtime.
~http://www.oracle.com/technology/tech/java/oc4j/10131/how_to/how-to-swapxmlparser/doc/readme.html
We did look at a number of other solutions including embedding the java classes I'd written into the database. After loading the apache Xerces api's into our schema we hit upon the same problem. It seems that the same thing happens in the database and the Oracle XML parser is used by default.. Please see SR Number : 6153038.994 on Metalink.
If you can upgrade to AS 10.1.3 then you can follow the excellent how to at:http://www.oracle.com/technology/tech/java/oc4j/10131/how_to/how-to-swapxmlparser/doc/readme.html . Demo code can be found at: http://www.oracle.com/technology/tech/java/oc4j/10131/how_to/how-to-swapxmlparser/how-to-swapxmlparser.zip
The how-to details how to swap xml parsers within the application server.
Other possible solutions that are also available include:
- Shelling out to the OS from the DB or Apps Server, You can then execute the app as a command line app with a custom classpath. Very bad architecture design.
- Setting up an RMI client / server application where client is the db or apps server. You can find examples of this on the web. google 'Simple RMI example'.
- Bootstrapping the XML parser in AS 10.1.2 (unsupported).
I hope people have found this informative. It might save someone a lot of time.
Message was edited by:
Kris Jones

Answer 1

"When I was installing SOA 10.1.3.1.0 on oracle 10.2.0.1 and it was giving error that it needs minimum 10.2.0.3, just wondering 10.1.2.0.2 + SOA =will this work?"
so you talk about the db version. SOA 10.1.3.x runs on 10.2.0.1 and above (I ran for the longest time on XE) and if I remember correctly that's a warning, and not a hard prereq.
Regarding Appserver versions - soa 10.1.3 runs on AS 10.1.3 only