This section has information on various debugging techniques. In addition to the logging information available off of the WPF Serviceability
page, developers often need to be able to determine what is happening in the application and its state, just before and when a problem occurs. WebSphere Portlet Factory provides multiple mechanisms and techniques to help you resolve such issues, as described below.
Please feel free to help complete this section! To describe techniques in detail, you can create new pages and link them from here.
Debugging and Troubleshooting techniques
- Look for builder errors and warning messages in the Eclipse based Designer's "Problems" view.
- Don't try to run models that still have Errors listed in the problems view - resolve the errors first.
- Try double-clicking on generic looking errors such as "An error occurred during model generation" to see if there is more info.
- Use the available Logging information to help determine what types of errors and exceptions are causing the undesirable behavior you're trying to diagnose.
- Use Java-level debugging to do single-step and set breakpoints in generated or LJO (Linked Java Object) code. See the following section of the product documentation for more information on this: Debug with Eclipse/RAD using Factory Model Execution Debugging: wpf7.
- Implement application level logging with log4j that can be enabled/disabled during deployment. See above referenced logging page for more details.
- Use System.out.println in Action List or Java code (Method builder and LJO methods), or use the Debug Tracing builder to print out values.
- Printing out status messages (like entering and exiting methods / action lists, and printing current variable values) can help determine how far and where your app is getting to before / when problems occur.
- Use Model Action Tracing to see exactly what actions get executed at runtime, and how long each is taking to execute.
- Look at generated code and pages in the WebApp Tree view of Designer.
- When making custom builders or troubleshooting problems with existing builders, start Eclipse with "-debug -console" flags in order to see builder println output
- Review the Application Server console log and/or standard out and error logs (eg, SystemOut and SystemError for WebSphere Application Server) for errors related to the issue you are diagnosing.
The online WPF product documentation includes an overview of debugging WPF based portlets and applications.
http://publib.boulder.ibm.co m/infocenter /wpf help/v6r1m2/index.jsp?topic=/com.bowstreet.designer.doc/designer/c_overview_debugging.htm