java编程实现基于UDP协议传输数据的方法

本文实例讲述了java编程实现基于UDP协议传输数据的方法。分享给大家供大家参考，具体如下：

UDP协议（User Datagram Protocol,用户数据报协议）不同于TCP协议，它是不可能靠的，但是它比TCP协议具有更快的传输速度，UDP发送的数据单元称为数据报，当网络传输UDP传输UDP数据报是无法保证数据能够到达目的地，也无法保证按发送的顺序到达目的地，也就是说先发送了“hello”,再发送了“world”,但接收方可能会先收到“world”,再收到“hello”,也有可能收不到数据，为什么呢？因为它是不可能靠的，在传输途中可能丢失了。但UDP比TCP跟适合与传输实时音频。下面是一个简单的UPD传输数据报的例子

服务器端：

import java.io.IOException;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.SocketException;
public class EchoServer {
 private DatagramSocket datagramSocket;
 private final int port = 8088;
 public static void main(String[] args) throws SocketException {
  new EchoServer().service();
 }
 public EchoServer() throws SocketException{
  datagramSocket = new DatagramSocket(port);
  System.out.println("服务器启动");
 }
 public String echo(String msg){
  return "echo:"+msg;
 }
 public void service(){
  while (true) {
   try {
    DatagramPacket packet = new DatagramPacket(new byte[512], 512);
    datagramSocket.receive(packet);
    String msg = new String(packet.getData(), 0, packet.getLength());
    System.out.println(packet.getAddress()+"/"+packet.getPort()+" msg:"+msg);
    packet.setData(echo(msg).getBytes());
    datagramSocket.send(packet);
   } catch (IOException e) {
    e.printStackTrace();
   }
  }
 }
}

客户端：

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;
import java.net.SocketException;
public class EchoClient {
 private String remoteHost="localhost";
 private int remotePort=8088;
 private DatagramSocket datagramSocket;
 public EchoClient() throws SocketException{
  datagramSocket = new DatagramSocket();
 }
 public static void main(String[] args) throws SocketException {
  new EchoClient().talk();
 }
 public void talk(){
  try {
   BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
   String msg = null;
   InetAddress address = InetAddress.getByName(remoteHost);
   while ((msg=reader.readLine())!=null) {
    //发送数据报
    byte [] buffer = msg.getBytes();
    DatagramPacket packet = new DatagramPacket(buffer,buffer.length, address, remotePort);
    datagramSocket.send(packet);
    //接收数据报
    DatagramPacket inputPacket = new DatagramPacket(new byte[512], 512);
    datagramSocket.receive(inputPacket);
    System.out.println(new String(inputPacket.getData(), 0 , inputPacket.getLength()));
    if("bye".equals(msg)){
     break;
    }
   }
  } catch (IOException e) {
   e.printStackTrace();
  }finally{
   datagramSocket.close();
  }
}

希望本文所述对大家Java程序设计有所帮助。