I\'ve recently stumbled across geb and it looks like a good way to perform integration tests on our web applications. Our platforms are all java based and from reading that
Geb is designed for, and can only be used from, Groovy code. This is mainly due to the dynamic nature of its APIs. What you can choose is which test framework to use (JUnit, TestNG, Spock, etc.). As Geb itself is just a library, it can also be used without a test framework, for example to automate an interaction with a website.
If you need to stick to Java, you'll have to use something like Selenium2, which is what Geb uses under the covers.