线程的概念、属性；线性创建的2种方式及其联系、区别和使用场合；线程的生命周期和5种状态；线程状态控制的一般方法；线程同步的概念、原理；线程同步的场合、线程同步的条件、同步对象的选取；线程间通讯的概念，与线程同步的区别；notify和wait的使用方法。两类socket通信的概念、特点、应用场合；两类socket通信的客户和服务端的基本步骤；组播通信的概念、组播客户端服务端的基本结构。-threads concept attribute; The creation of two linear models and their connections, and the use of different occasions; Threads of the life cycle and five state; Thread the general state control; Thread synchronization concept, principle; Thread Synchronization occasions, thread synchronization, the synchronization like the selection; Thread the concept of communication, and synchronization of different threads; notify the wait and use. Two types of socket communication concept, features, applications; Two types of socket communication and customer service side of the basic steps; The concept of multicast communication, multicast client services side of the basic structure.