Mockito is an open-source, Java-based, mocking framework that allows the CREATION of test objects that SIMULATE the behaviour (mock) of real-world objects. This helps in achieving test-driven or behaviour-driven development. The framework allows developers to verify system behaviours without ESTABLISHING expectations. Mockito framework attempts to eliminate expect-run-verify development patterns by removing external specifications and dependencies. Some of the advantages of Mockito are:

• Mocks are created at RUNTIME, hence reordering method input parameters or renaming interface methods will not break test code.
• Mockito SUPPORTS returning of values.
• It supports exception simulation
• It provides a check on the order of method calls.
• It helps in creating mock objects using annotation.