一个简单的Java程序，实现了局域网多播功能，适用初学者。-A simple Java program, the realization of a local area network multicast function for beginners.

这是一个类似于QQ的即时通讯的程序，基于socket的TCP通信，支持并发多线程，带Swing界面。-This is a similar QQ instant communication program, TCP communication based on socket, supports multiple threads concurrently, with Swing interface.