Writing good concise tests for application components can be quite cumbersome. Especially, when they have a lot of dependencies to other beans and you do not want to manually write mock objects to fulfill all of them. On the other hand, you do not want to run too many slow integration tests.
We still see the need for a lightweight framework that allows to test components in isolation where their dependencies are resolved in an arbitrary manner. Sometimes you might want to use mock objects for dependencies, sometimes you would like to link your component to the real world.
With the Needle framework you can accomplish those goals in very comfortable way. Objects under test will get their dependencies injected automatically. The Needle core is extensible, it allows you to add your own injection points at run time. You are free to supply implementations yourself or rely on the mock objects provided by Needle. Needle will thus minimize the setup code and maximize the speed of a unit test.