Is there a program that can tell you which class/method is being invoked

Question

I'm working on a very big java/servlets/web project and i find it hard finding which classes and and methods is being called. sometimes it takes hours to find the right class. if there an application or plugin or technique that helps a little? im using eclipse.

edit: I'm using apache and tomcat

Answer 1

Regarding your comment to Bozhos answer: use a profiler on your server instance. You start profiling right before you click on a link in your client application ("the browser") and stop right after you have the correct response. Then just examine the profiler logs/views to find out, what actually happend on the server.

The Eclipse Test & Performance Tools Platform Project is worth a try.

Answer 2

• CTRL + ALT + H , or right-click > open call hierarchy (when on a method declaration) will give you all callers, with their callers, and so on. You can also reverse the hierarchy

• Right click > references > project will give you where a given class is used.

Answer 3

From your comment on Bhozo's answer I conclude that you do NOT mean at development time, but at runtime.

I suggest you connect a debugger to your application and pause it. You can then inspect the callstack at that time, which will usually give you an idea where to look.

To do that, run your java app with the following settings:

-Xdebug -Xrunjdwp:transport=dt_socket,address=8787,server=y,suspend=n

Then in eclipse, add a debug configuration for 'remote' to port 8787 and execute it. Your debugger is now linked to your application. Put eclipse into the debug perspective.

Now click a link in your application, and immediately click the pause button in the debugger. You can now see the callstack. Usually, once you have a clue, you can quickly find good spots to put breakpoints. But this technique helps you get a clue :)

Answer 4

You might want to consider the use of AOP to add a tracing/logging aspect to certain parts of your code. This way you don't have to update your code and can simply write an aspect that logs a line for every method that is called with in example the name of the method, the class and the parameters. This aspect can of course be 'turned off' when building your production version to prevent the trace logging on production machines. If you're familiar with AOP, you can easily tweak the aspect and the pointcuts a bit to for instance only log calls to certain methods in your controller classes or something like that.

If you need more information on this solution, feel free to comment on this answer requesting more specific information or simply google for AOP and logging.