I'm implementing a project for Google App Engine.
At this moment I have the following setup:
- I have a couple of servlets in place to will give some data back to a client application (for example Android/iOS client)
- To test this servlets I created junit tests accessing this servlets.
- Inside the servlets there is some logic to determine if we are running tests or doing actually calls from a client. If we are running tests on a local machine we initialize a LocalServiceTestHelper to get the datastore, memcache, etc. working.
This all works fine.
Now comes the problem. When I add the AppStats filter to my web.xml, this also applies to the servlets when they are used in the locale junit tests. But the AppStats filter doesn't work. I get the following stacktrace when I run my tests:
java.lang.NullPointerException
at com.google.appengine.tools.appstats.Recorder.checkNotNull(Recorder.java:378)
at com.google.appengine.tools.appstats.Recorder.<init>(Recorder.java:210)
at com.google.appengine.tools.appstats.Recorder.<init>(Recorder.java:200)
at com.google.appengine.tools.appstats.AppstatsFilter.init(AppstatsFilter.java:183)
at org.mortbay.jetty.servlet.FilterHolder.doStart(FilterHolder.java:97)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.servlet.ServletHandler.initialize(ServletHandler.java:593)
at org.mortbay.jetty.servlet.Context.startContext(Context.java:140)
at org.mortbay.jetty.webapp.WebAppContext.startContext(WebAppContext.java:1220)
at org.mortbay.jetty.handler.ContextHandler.doStart(ContextHandler.java:513)
at org.mortbay.jetty.webapp.WebAppContext.doStart(WebAppContext.java:448)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.handler.RequestLogHandler.doStart(RequestLogHandler.java:115)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at org.mortbay.jetty.handler.HandlerWrapper.doStart(HandlerWrapper.java:130)
at org.mortbay.jetty.Server.doStart(Server.java:222)
at org.mortbay.component.AbstractLifeCycle.start(AbstractLifeCycle.java:39)
at com.google.gwt.dev.shell.jetty.JettyLauncher.start(JettyLauncher.java:672)
at com.google.gwt.dev.DevMode.doStartUpServer(DevMode.java:509)
at com.google.gwt.dev.DevModeBase.startUp(DevModeBase.java:1093)
at com.google.gwt.junit.JUnitShell.getUnitTestShell(JUnitShell.java:707)
at com.google.gwt.junit.JUnitShell.runTest(JUnitShell.java:652)
at com.google.gwt.junit.client.GWTTestCase.runTest(GWTTestCase.java:441)
at junit.framework.TestCase.runBare(TestCase.java:141)
at junit.framework.TestResult$1.protect(TestResult.java:122)
at junit.framework.TestResult.runProtected(TestResult.java:142)
at junit.framework.TestResult.run(TestResult.java:125)
at junit.framework.TestCase.run(TestCase.java:129)
at com.google.gwt.junit.client.GWTTestCase.run(GWTTestCase.java:296)
at junit.framework.TestSuite.runTest(TestSuite.java:255)
at junit.framework.TestSuite.run(TestSuite.java:250)
at junit.framework.TestSuite.runTest(TestSuite.java:255)
at junit.framework.TestSuite.run(TestSuite.java:250)
at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.run(JUnitTestRunner.java:518)
at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.launch(JUnitTestRunner.java:1052)
at org.apache.tools.ant.taskdefs.optional.junit.JUnitTestRunner.main(JUnitTestRunner.java:906)
Anybody has any idea why the AppStats gets a NullPointerException?
As far as I see I have two options here:
- Get the AppStats filter to work in my current junit tests.
- Disable the AppStats filter for my locale junit tests but keep it active for normal calls to the servlets.
Both are fine, but I prefer to go with option 1.
Update april 19th 2013:
- I tried initializing the MemCache before the filter (as mentioned below), but that doesn't seem to resolve anything. Same stacktrace as before.
- From the Recorder.java source I figured out that probably the Delegate parameter in the constructor is null, but I have no idea why. (https://code.google.com/p/googleappengine/source/browse/trunk/java/src/main/com/google/appengine/tools/appstats/Recorder.java)
