Udp简单的服务器与客户端07

UDP协议：
UDP协议传输数据是不可靠的，在java中，java.util.DatagramSocket负责接收和发送UDP数据报，java.util.DatagramPacket表示UDP数据表。每个
DatagramSocket与一个本底地址绑定，每个DatagramSocket可以把UDP数据报发送给任意一个远程DatagramSocket，也可以接收来自任意一个远程的
DatagramSocket的UDP数据报。在UDP数据报中包含了目的地址信息，DatagramSocket根据该信息把数据报发送到目的地

UDP服务端

1public class EchoServer{
2    
3    private int port = 8089;
4    private DatagramSocket socket;
5    
6    public EchoServer()throws IOException{
7        socket = new DatagramSocket(port);
8        System.out.println("服务端启动");
9    }
10    
11    public String ehco(String msg){
12        return "ehco:"+msg;
13    }
14    
15    public void service(){
16        while(true){
17            try {
18                //创建一个数据报对象
19                DatagramPacket packet = new DatagramPacket(new byte[512], 512);
20                socket.receive(packet);//接收来自任意一个EhcoClient的数据报
21                String msg = new String(packet.getData(), 0, packet.getLength());
22                System.out.println(packet.getAddress()+":"+packet.getPort()+">"+msg);
23                packet.setData(ehco(msg).getBytes());//给EchoClient发送数据报
24                socket.send(packet);
25            } catch (Exception e) {
26                e.printStackTrace();
27            }
28        }
29    }
30    
31    public static void main(String[] args) throws IOException {
32        new EchoServer().service();
33    }
34    
35}

UDP客户端

1public class EchoClient {
2
3    private String remoteHost = "localhost";
4    private int remotePort = 8089;
5    private DatagramSocket socket;
6    
7    public EchoClient() throws SocketException{
8        socket = new DatagramSocket();//与本地任意的端口绑定
9    }
10    
11    public void talk() throws IOException{
12        try{
13            //获取服务端ip地址
14            InetAddress remoteIP = InetAddress.getByName(remoteHost);
15            
16            BufferedReader localReader = new BufferedReader(new InputStreamReader(System.in));
17            String msg = null;
18            while((msg = localReader.readLine()) != null){
19                byte[] outputData = msg.getBytes();
20                DatagramPacket outputPacket = new DatagramPacket(
21                        outputData, outputData.length,remoteIP,remotePort);
22                
23                socket.send(outputPacket);//发送数据报
24                
25                DatagramPacket inputPacket = new DatagramPacket(new byte[512], 512);
26                socket.receive(inputPacket);//接收EchoServer的数据报
27                System.out.println(new String(inputPacket.getData(),0,inputPacket.getLength()));
28                if(msg.equals("bye")){
29                    break;
30                }
31            }
32        }catch (Exception e) {
33            e.printStackTrace();
34        }finally{
35            socket.close();
36        }
37    }
38    
39    public static void main(String[] args) throws SocketException, IOException {
40        new EchoClient().talk();
41    }
42    
43}