import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;import java.net.SocketException;public class test_udp_send {    public static void main(String arg[]) throws Exception{        DatagramSocket dSocket=new DatagramSocket(3000);        String string ="Hello,word";        DatagramPacket datagramPacket=new DatagramPacket(string.getBytes(), string.length(),InetAddress.getByName("127.0.0.1"),8001);        dSocket.send(datagramPacket);        dSocket.close();    }}

import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.SocketException;public class test_udp_server {    public static void main(String args[]) throws Exception{        byte buf[]=new byte[1024];        DatagramSocket dSocket= new DatagramSocket(8001);        DatagramPacket datagramPacket=new DatagramPacket(buf, 1024);        dSocket.receive(datagramPacket);        String str=new String(datagramPacket.getData());        System.out.println(str);        dSocket.close();            }}

import java.io.IOException;import java.io.InputStream;import java.net.InetAddress;import java.net.Socket;public class test_tcp_send {public static void main(String arg[]) throws Exception{    new client().connect();    }}class client{        public void connect() throws Exception, IOException{        Socket client=new Socket(InetAddress.getLocalHost(),8009);        InputStream inputStream=client.getInputStream();        byte buf[]=new byte[1024];        int length=inputStream.read(buf);        System.out.println(new String(buf));        client.close();    }}

public class test_tcp_server {    public static void main(String args[]) throws Exception    {        new server().connect();    }}class server{        public void connect() throws Exception{                ServerSocket serverSocket=new ServerSocket(8009);        Socket client=serverSocket.accept();        OutputStream outputStream=client.getOutputStream();        outputStream.write("hello,word".getBytes());        outputStream.close();        client.close();    }}