Can you recommend a simple/best tool for an web application developed using Wicket framework?
The challenge is interface id is changed every time so record and playback may not work. This link explains some work around but it is not simple to implement.
Besides JMeter you can try Selenium to test web applications. If you use Selenium you show also check Selenium Inspector which is build on top of it and provides convenient assertion methods.
Online service BrowserMob offers cloud based load testing based on selenium.
Because the web framework like wicket is on the server side but the load testing tool operates on the client side almost any load testing tools should do the job.
What may be worth a look, depending on your needs:
Apache AB - The 1st generation load testing tool. It just requests defined urls. However, it's very fast you can easily create a high load from a regular computer. It's a console application
JMeter - One of the first script load testing tools. You can program a test via clicks from some basic actions/validations using a swing interface. Or you can use the proxy recorder to save some amount of work. But, to be honest, the tool doesn't satisfy me anymore these days.
The Grinder - A nice tool - you program the test case via python (in fact jython). This makes complex testing scenarios easily possible. This should defnitly work with wicket, but this tool is also getting old.
Deja Click - A firefox plugin which allows recording and replaying web actions. Intentionally not written for web tests and load tests, but it may be worth a look
Selenium - The 3rd generation of web load testing tools with a big community behind it. You record and edit your test cases via a firefox plugin. Because of the browser integration, more complex tests cases can be recorded in a shorter period of time. You should really have a look at this, but keep in mind that Selenium is a acceptance testing tool, and not designed for load testing, but you can do it, if your hardware allows ist. However, you might be in troubles recording the tests if your application does not run in firefox.
LoadRunner - A commercial and well-known load testing tool by HP. Haven't tried this yet.
WebLOAD - Another commercial alternative.