This section contains links to further resources about testing in general.
JUnit: the Spring Framework's unit and integration test suite is written using JUnit 3.8 and JUnit 4.5 as the testing framework.
TestNG: a testing framework inspired by JUnit 3.8 with added support for Java 5 annotations, test groups, data-driven testing, distributed testing, etc.
MockObjects.com: a website dedicated to mock objects, a technique for improving the design of code within Test-Driven Development.
"Mock Objects": article at Wikipedia.
EasyMock: the Spring Framework uses EasyMock extensively in its test suite.
JMock: a library that supports test-driven development of Java code with mock objects.
DbUnit: a JUnit extension (also usable with Ant and Maven) targeted for database-driven projects that, among other things, puts your database into a known state between test runs.
Grinder: a Java load testing framework.