这是一个包含用户界面的聊天软件，使用Java语言进行编辑。

采用了非常高效的编码逻辑，可以实现server端和client端。-It is the implementation of GUI for a chat room program.

Behaviors (Server)

When the server starts up, it should try to load from “accounts.dat” for saved accounts

o Each account consists of the username, the password and last login time of the user

o You need to decide how the data should be stored

o The file should be created automatically if it does not exist.

The server should update “accounts.dat” accordingly whenever is needed.

The server should handle connections from clients

o When a client login or logout, the server should update all other clients about it

o When a client send a message, the server should redirect the message to all other

clients

o When a client change password, the server should update its record accordingly

The server should communicate with the client by sending objects (i.e., using

ObjectInputStream and ObjectOutputStream)



For the client

The buddy list will be updated automatically when someone logged in or out.

When a user send a messag