Tomcat Lib Instrumenting Question about cobertura

[christ66]

It should work without any issues, please read: https://github.com/cobertura/cobertura/wiki/FAQ and search for the Tomcat section.

[hkamran]

Haha, works. I noticed there is a way to force the cobertura ser file to be written while the server is on, is there a way to clear the cobertura data so I don't have to restart tomcat to get a fresh coverage?

[christ66]

There is no safe way to clear the cobertura data. Cobertura data does not get written until jvm shutdown hooks are executed.

There might be a few ways, however that could involve a lot of hacking which I would strongly advise against. However here is the hack. For each class that gets instrumented, we add a method

  public static int[] __cobertura_get_and_reset_counters() {...}

which can be called using reflection. However this will require that you scan every single class loaded in the jvm to see if it contains the method above and invoke it with reflection.

            String className = "Name.Of.Instrumented.Class";
            String methodName = "__cobertura_get_and_reset_counters";
            Class saveClass = Class.forName(className);
            java.lang.reflect.Method saveMethod = saveClass.getDeclaredMethod(
                    methodName, new Class[0]);
            saveMethod.invoke(null, new Object[0]);

Also a try-catch block would need to go around the invoke call just in case the method does not exist. If you can provide a use case where resetting the count could be useful, I could write something for the FlushCoberturaServlet to allow for resetting of all coverage information.

[hkamran]

We'll we run automated tests and when I do a full run I would love to do a reset on the instrumented files, run tests, dump ser, create report. I'm not to fond of using scripting to do the work of rebooting the server as it leaves the automated tests system dependent.

[christ66]

I'm not sure I understand the process you are doing. Are you trying to do the following:

1. Reset instrumented files
2. run tests
3. dump ser
4. create report

Step 1 is not necessary because cobertura when it initially starts it is at 0 everything. Step 3 can be achieved using the coberturaFlush.war file where you can flush cobertura data at anytime. Also see the FAQ (last part) on how to create your own cobertura flushing part (e.x. when logout button is pressed). We also have a test unit (WebAppFunctionalTest.java) that flushes cobertura information while (in our case a jetty servlet) is still running.