求一个java代码详细设计的例子，以接口为主的

import java.net.*;
import java.io.*;
import java.util.*;
public class ChatRoomServer {
	public static void main(String[] args) throws Exception{
		ServerSocket ss=new ServerSocket(8000);
		List sockets=new ArrayList();
		while(true){
			Socket s=ss.accept();
			sockets.add(s);
			Thread t=new ServerThread1(s,sockets);
			t.start();
		}
	}
}
class ServerThread1 extends Thread{
	Socket s;
	List sockets;
	public ServerThread1(Socket s,List sockets) {
		super();
		this.s = s;
		this.sockets=sockets;
	}
	public void run(){
		try {
			BufferedReader in=new BufferedReader(
					new InputStreamReader(s.getInputStream()) );
			while(true){
				String text=in.readLine();
				if (text==null) return;
				for(int i=0;i<sockets.size();i++){
					Socket s2=(Socket)sockets.get(i);
					PrintWriter out=new PrintWriter(s2.getOutputStream());
					out.println(text);
					out.flush();
				}

			}
		} catch (IOException e) {}
		finally{
			this.sockets.remove(s);
		}
	}
}

import javax.swing.*;
import java.awt.event.*;
import java.net.*;
import java.io.*;
public class ChatRoomClient {
	JFrame frame;
	JTextField jtf;
	JTextArea jta;
	Socket s;
	BufferedReader in;
	PrintWriter out;

	public static void main(String[] args) {
		ChatRoomClient c=new ChatRoomClient();
		c.receive();
	}

	public ChatRoomClient(){
		frame=new JFrame("Chat Room");
		frame.setSize(400,300);
		frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		jta=new JTextArea();
		JScrollPane jsp=new JScrollPane(jta);
		frame.add(jsp);

		jta.setEditable(false);

		jtf=new JTextField();
		frame.add(jtf,"South");

		frame.setVisible(true);

		try {
			s=new Socket("localhost",8000);
			in=new BufferedReader(new InputStreamReader(s.getInputStream()));
			out=new PrintWriter(s.getOutputStream());
		} catch (UnknownHostException e1) {
			e1.printStackTrace();
		} catch (IOException e1) {
			e1.printStackTrace();
		}

		jtf.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent e){
				String text=jtf.getText();
				jtf.setText("");
				out.println(text);
				out.flush();
			}
		});
	}

	public void receive(){
		try {
			while(true){
				String text=in.readLine();
				jta.append(text+"\n");
			}
		} catch (IOException e) {
			e.printStackTrace();
		}
	}
} 

先运行ChatRoomServer ，再运行ChatRoomClient