网络编程(二)

package tcpudp;
import java.net.*;
import java.io.*;
public class UDPClient{
    public static void main(String args[]){ 
    // args give message contents and destination hostname
      System.out.println("UDP Client starting, please enter: ");
    DatagramSocket aSocket = null;
    BufferedReader br = new BufferedReader(new InputStreamReader(System.in));//接受控制台信息
      String line = null; 
    try {      
       while((line = br.readLine())!=null){
         aSocket = new DatagramSocket();
         if("bye".equals(line))
           break;
         byte[] m = line.getBytes();//字节数组
         DatagramPacket request = new DatagramPacket(m, m.length, InetAddress.getByName("127.0.0.1"),33333);
         aSocket.send(request);          
         }
    }catch (SocketException e){
      System.out.println("Socket: " + e.getMessage());
    }catch (IOException e){
      System.out.println("IO: " + e.getMessage());
    }finally{
      if(aSocket != null) 
        aSocket.close();
    }
  }           
}

package tcpudp;
import java.net.*;
import java.io.*;
public class UDPServer{
    public static void main(String args[]){ 
      System.out.println("UDP server starting, wait....");
      //接受
      DatagramSocket aSocket = null;
    try{
        aSocket = new DatagramSocket(33333);
       // create socket at agreed port
      byte[] buffer = new byte[1024];
      while(true){
        DatagramPacket request = new DatagramPacket(buffer, buffer.length);
          aSocket.receive(request);         
            String data = new String(request.getData(),0,request.getLength());
              String ip = request.getAddress().getHostAddress();
            if("bye".equals(data))
         break;
            System.out.println(ip+":"+data);            
        }
    }catch (SocketException e){
      System.out.println("Socket: " + e.getMessage());
    }catch (IOException e) {
      System.out.println("IO: " + e.getMessage());
    }finally {
      aSocket.close();
    }
    }
}