Hello Gemini Web devs,
We are using Gemini Web with Equinox and we had to update our test setup recently to reload a web application, while Tomcat is running. We ended up using Tomcat JMX for that, but it turned out a NPE is thrown when the web application is re-started. The issue is reproducible with any web application bundle. To reproduce it with latest Gemini Web 2.2.2 and the "simple-war.war" web application, follow these steps:
1. Install the war in Equinox:
osgi> install file:simple-war.war
2. Run
jconsole JDK tool and connect to the Equinox process
3. Open the "//localhost/simple-war" node under "Catalina/WebModule", navigate to the operations and execute "reload"
4. Observe the following exception appears in Equinox console:
org.apache.catalina.core.StandardContext reload
SEVERE: Exception starting Context with name [/simple-war]
org.apache.catalina.LifecycleException: Failed to start component [StandardEngine[Catalina].StandardHost[localhost].StandardContext[/simple-war]]
at org.apache.catalina.util.LifecycleBase.start(LifecycleBase.java:154)
at org.apache.catalina.core.StandardContext.reload(StandardContext.java:3926)
...
Caused by: org.apache.catalina.LifecycleException: Failed to start component [org.eclipse.gemini.web.tomcat.internal.loading.BundleWebappLoader@6638e53]
...
Caused by: java.lang.NullPointerException
at org.eclipse.gemini.web.tomcat.internal.loading.BundleClassPathURLExtractor.extractBundleClassPathURLs(BundleClassPathURLExtractor.java:37)
at org.eclipse.gemini.web.tomcat.internal.loading.BundleWebappClassLoader.addBundleClassPathURLs(BundleWebappClassLoader.java:101)
at org.eclipse.gemini.web.tomcat.internal.loading.BundleWebappClassLoader.<init>(BundleWebappClassLoader.java:77)
at org.eclipse.gemini.web.tomcat.internal.loading.BundleWebappLoader.createClassLoader(BundleWebappLoader.java:88)
at org.eclipse.gemini.web.tomcat.internal.loading.BundleWebappLoader.startInternal(BundleWebappLoader.java:169)
These are initialized in the constructor and since a new BundleWebappClassLoader instance is not created when starting the context after a stop, these remain null and ultimately cause the exception.
It seems like the fix would be easy - removing the respective null assigments so that the "bundle" and "classLoaderCustomizer" instances are preserved. If there are no side effects and there is no specific reason for this piece of code, I would open a defect and attach a patch, but first I wanted to get your opinion on this. Does this sound reasonable?
Thanks,
Detelin
