使用Java 提供的RMI 函数实现一个远程函数调用过程。要产生远端对象时，必须明确定义其接口(Interface)，通过接口可以隐藏底层实现-Using Java RMI provides functions to implement a remote function call. To generate a remote object, you must explicitly define its interface (Interface), through the interface can hide the underlying implementation