JUnit: Tests the ordinary Java class.
CACTUS: Perform a container test. Such as test servlet, jsp, ejb
http://jakarta.apache.org/cactus/
http://jakarta.apache.org/cactus/getting_started.html
HttpUnit: Used to integrate testing.
http://httpunit.sourceforge.net/
JMeter: For pressure testing.
http://www-900.ibm.com/developerWorks/cn/java/l-jmeter/
Struts can be tested with Strutstestcase
http://sourceforge.net/projects/strutstestcase/
