UDP连接

public class TestUDPServer
{
    public static void main(String[] args) throws Exception
    {
        byte[] buf = new byte[1024]; //接受客户端数据存入buf中  

        DatagramPacket dp = new DatagramPacket(buf,buf.length);

        DatagramSocket ds = new DatagramSocket(5678);

        while(true)
        {
            ds.receive(dp);
            ByteArrayInputStream bi = new ByteArrayInputStream(buf);
            DataInputStream in = new DataInputStream(bi);
            System.out.println(in.readLong());
        }
    }
}


public class TestUDPClient
{
    public static void main(String[] args) throws Exception
    {
        //byte[] buf = (new String("hello")).getBytes();

        long n = 10000L;
        ByteArrayOutputStream bos = new ByteArrayOutputStream();
        DataOutputStream dos = new DataOutputStream(bos);

        dos.writeLong(n);

        byte[] buf = bos.toByteArray();

        DatagramPacket dp = new DatagramPacket(buf,buf.length,
                new InetSocketAddress("127.0.0.1",5678));

        DatagramSocket ds = new DatagramSocket(9999); //client本身占据了9999端口向5678端口发数据

        ds.send(dp);
        ds.close();
    }
}