With the packet NIO in the JDK1.4, the mechanism of the asynchronous input and output is introduced to solve the I/O obstruction problem and these techniques applied to the socket programming are shown to reduce the system cost. ?

• Javasocket编程中最令人头疼的莫过于为解决阻塞而大量使用线程导致系统开销大的问题；随着jdk1.；4推出NIO包；引入了异步输入输出机制从而解决了I/O阻塞问题；这里展示了如何在Socket编程中使用这些技术来减少系统开销。