ServerSocket01
package socket;

import java.io.PrintStream;
import java.net.ServerSocket;
import java.net.Socket;

public class ServerSocket01 {
	public static void main(String[] args) {
		ServerSocket server = null;
		try{
//			服務器在9999端口開辟了服務
			server = new ServerSocket(9999);
		}catch(Exception e){}
//		對于服務器而言，所有用戶的請求都是通過ServerSocket實現
		Socket client = null;
		try{
//			服務器在此等待用戶的鏈接
			System.out.println("等待客戶端連接...");
			client = server.accept();//服務端受到的一個client
		}catch(Exception e){}
//		要向客戶端打印信息
		PrintStream out = null;
//		得到向客戶端輸出信息的能力
		try{
			out = new PrintStream(client.getOutputStream());
		}catch(Exception e){}
		out.println("How are you ?");
		try{
			client.close();
			server.close();
		}catch(Exception e){}
		System.out.println("客戶端回應完畢...");

	}

}

ClientSocket01
package socket;

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.net.Socket;

public class ClientSocket01 {
	public static void main(String[] args) {
		Socket client=null;
		try {
//			實際上表示要鏈接到服務器上去了
			client=new Socket("192.168.0.2",9999);
			//192.168.0.2是本人的局域網IP地址
		} catch (Exception e) {} 
//		等待服務器的回應
		String str = null;
//		如果直接使用InputStream接收會比較麻煩
		BufferedReader buf = null;
		try{
			buf = new BufferedReader(new InputStreamReader(client.getInputStream()));
			str = buf.readLine();
		}catch(Exception e){}
		System.out.println(str);
	}

}