Abstract
Along with the high-speed development of Internet ， produced a series of new
things related to the Internet， instant messaging system is the product of one of the most
representative。 Instant messaging system through constant development， with its fast,
convenient, real-time characteristics, becoming an important communication tool， get the
favour of a growing number of Internet users。 Instant messaging system development
mainly includes two aspects： instant messaging system server client， instant messaging
system design。 Instant messaging system design mainly through the Socket server Socket
server, the server can read and forward from the client's information, and be able to refresh
the user list 。 Instant messaging system design mainly by the client and the server
connection is established ， which makes the server to communicate with the client’s
information。 Here, the principle has been using network communication mechanism，
through direct inheritance for building a multithreaded Thread class. At the same time，
the use of computer network programming in the development of the basic theory of
knowledge ， such as TCP/IP protocol, Client/Server mode （ Client/Server mode) ，
network programming design method, etc. Using flow in network programming to achieve
the exchange of information, so as to read and send information。 Instant messaging system
using myeclipse as the basic development environment and the Java language to write, by
constantly revised and improved the initial prototype system ， until the system is
completely feasible.
Key words：Instant messaging system ;socket ;Java
