java学习之tcp与udp的实现

 package com.gh.socket;

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

 /**
  * tcp客户端程序
  * @author ganhang
  */
 public class ClientDemo {
     public static void main(String[] args) {
         try {
             Socket sk=new Socket("",8888);
             System.out.println("与服务器连接成功");
             BufferedReader br=new BufferedReader(new InputStreamReader(sk.getInputStream()));
             String info=br.readLine();
             br.close();
             System.out.println(info);
         } catch (UnknownHostException e) {
             e.printStackTrace();
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
 }

 package com.gh.socket;

 import java.io.BufferedWriter;
 import java.io.IOException;
 import java.io.OutputStreamWriter;
 import java.net.ServerSocket;
 import java.net.Socket;

 /**
  * tcp服务器端
  * @author ganhang
  *
  */
 public class ServerDemo {
     public static void main(String[] args) {
         try {
             ServerSocket ss=new ServerSocket(8888);
             System.out.println("服务器已启动，正在连接。。。");
             Socket s=ss.accept();
             String info="你好，哈哈哈\n";
             BufferedWriter bw=new BufferedWriter(new OutputStreamWriter(s.getOutputStream()));
             bw.write(info);
             bw.close();
         } catch (IOException e) {
             e.printStackTrace();
         }
     }
 }

 package com.gh.UDP;

 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.InetAddress;
 /**
  * UDP的接收端
  * 实现消息的接收与回复
  * @author ganhang
  *
  */
 public class UDPClientDemo {
     public static void main(String[] args) {
         byte[] b=new byte[1024];
         DatagramPacket dp=new DatagramPacket(b, b.length);//用来接收的数据报包
         try {
             DatagramSocket ds=new DatagramSocket(5000);//客户端的收发套接字
             System.out.println("接收端正在等待接收数据。。");
             ds.receive(dp);//接收数据，该方法会造成阻塞
             System.out.println("接受成功，对方地址是"+dp.getAddress().getHostName()+":"+dp.getPort());
             System.out.println("对方说："+new String(dp.getData()));
             String info="你好，我是客户端";
             byte b1[]=info.getBytes();
             //用来发送的数据报包
             DatagramPacket dp1=new DatagramPacket(b1,0,b1.length,InetAddress.getByName(""),dp.getPort());
             ds.send(dp1);
             System.out.println("回复成功");
             ds.close();
         } catch (IOException e) {
             e.printStackTrace();
         }

     }
 }

package com.gh.UDP;

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;

/**
 * UDP发送端
 * 实现消息的发送，和接收对方的回复
 * 注意：用来接收的数据报包和用来发送的数据报包的构造方法是不同的
 * 同时发送有大小限制，最大为64K
 * @author ganhang
 *
 */
public class UDPServerDemo {
    public static void main(String[] args) {
        String info ="你好，我是服务器";
        byte [] b= info.getBytes();
         try {
             DatagramSocket ds =new DatagramSocket(8000);//服务段的收发套接字
             //用来发送的数据报包
            DatagramPacket dp =new DatagramPacket(b,b.length,
                    InetAddress.getByName("localhost"),5000);
            ds.send(dp);//发给客户端
            System.out.println("消息发送完毕，等待回复...");
            byte b1[]=new byte[1024];
            DatagramPacket dp1=new DatagramPacket(b1,b1.length);//用来接收的数据报包
            ds.receive(dp1);
            System.out.println("对方回复："+new String(dp1.getData()));
            ds.close();

            System.out.println();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}