Mock Objects

In a typical JUnit test, some data is set up that is passed to the code under test,
and the return value is verified. All this does is test data — or state.

Mock objects allow the classes surrounding the class under to test to be
replaced with fake or mock versions. This allows a class to be tested in isolation
from its dependencies.

如上描述JUnit测试的是状态，Mock Objects测试的是同其他类的交互

Mock Objects 是对类或接口的伪造实现，通常用来mock被测试类的依赖环境(empty shells)，他们比较简单所以不许要再被测试

 

The Mock Objects Library contains the following parts:

1. An expectation library to help define the expectations when creating
mock objects

2. Alternative APIs for many of the common JDK and J2EE libraries,
including network sockets, I/O, JDBC, Servlets, JMS, JNDI, and Java-
Mail. These alternative APIs extend the conventional APIs to include
clean interface separations from implementations, which allows code
that depends on these interfaces to be passed mock implementations —
as well as any other custom implementation — as needed.

3. Mock implementations for the APIs mentioned previously

4. A library for dynamically creating mocks at runtime from your unit
tests without having to define extra classes. This uses dynamic proxies.

The Mock Objects Library 通过CGLib的动态代理实现mock功能