Thursday, October 14, 2004

Quiet day today. I finished going over the modifications to the remote resolver code, and got it to the point of trying to build.

I spoke to SR about the XAResource and where it will fit in. Not having used them much I thought that this was an object that would get used for managing the transaction, but SR is using it as a callback interface for each resolver. He hasn't implemented some of the finer details of distributed transactions, so for the moment he is happy for me to use the DummyXAResource class, as this just logs everything called on it.

I finished the day with failures in compilation. The compiler is complaining that it can't resolve classes that I have explicitly imported. This means that the compiler classpath must be at fault. This is annoying, as it can take a long time to find with jar is needed to get it right. Normally it would not be an issue, but Kowari is built as a single jar which in turn contains a large collection of jar files. Finding class files in jars, within jars can be very time consuming.

Jars within jars are not a common site, but it has certainly been handy, particularly when including third-party libraries. A few years ago TA wrote the code for this. From my understanding, it unzips the jar file into the temporary directory, and then uses a class loader to pick up all the new jar files. It's a bit tricky internally, but from the user's perspective it's ideal. This is why Kowari does not need a class path, and can just be launched with:
 java -jar kowari-1.0.x.jar

No comments: