Multhreading in Java

Question

I'm working with core java and IBM Websphere MQ 6.0. We have a standalone module say DBcomponent that hits the database and fetches a resultset based on the runtime query. The query is passed to the application via MQ messaging medium. We have a trigger configured for the queue which invokes the DBComponent whenever a message is available in the queue. The DBComponent consumes the message, constructs the query and returns the resultset to another queue. In this overall process we use log4j to log statements on a log file for auditing.

The connection is pooled to the database using Apache pool. I am trying to check whether the log messages are logged correctly using a sample program. The program places the input message to the queue and checks for the logs in the log file. Its expected for the trigger method invocation to complete before i try to check for the message in log file, but every time my program to check for log message gets executed first leading my check to failure.

Even if i introduce a Thread.sleep(time) doesn't solves the case. How can i make it to keep my method execution waiting until the trigger operation completes?

Any suggestion will be helpful.

Answer 1

I suggest you go and read up about the concurrency primitives that Java offers you. http://tutorials.jenkov.com/java-concurrency/index.html seems to cover the bases, the Thread Signalling chapter in particular.

Answer 2

I would recommend against relying on log4j (or any logging functionality) even in a simple test program.

Have your test run as you would expect it to, putting debugging/tracing statements in the log as you see fit (be liberal about it, log4j is very fast!) Then, when it's done, check the log yourself.

Writing log parsing will only complicate your goals.

Write your test, view the result, view the logs. If you want automated testing, consider setting up a functional test. You can set up tests free using Selenium. (http://seleniumhq.org/) There's no need to write your own functional testing/parsing stuff when there's easy to configure, easy to use, easy to customize frameworks out there! :-)