import java.net.*;import java.io.*;public class TestTCPServer {	public static void main(String[] args) {		InputStream in = null;		OutputStream out = null;				try {			ServerSocket ss  = new ServerSocket(8888);			Socket socket = ss.accept();			in = socket.getInputStream();			out = socket.getOutputStream();						DataInputStream dis = new DataInputStream(in);			DataOutputStream dos = new DataOutputStream(out);			String s = null;						if((s = dis.readUTF()) != null) {				System.out.println(s);				System.out.println("form:" + socket.getInetAddress());				System.out.println("port:" + socket.getPort());			}						dos.writeUTF("Hi, hello");			dis.close();			dos.close();			socket.close();								} catch(IOException e) {			e.printStackTrace();		}			}}

import java.net.*;import java.io.*;public class TestTCPClient {	public static void main(String[] args) {		InputStream in = null;		OutputStream out = null;				try {						Socket socket = new Socket("localhost", 8888);			in = socket.getInputStream();			out = socket.getOutputStream();						DataInputStream dis = new DataInputStream(in);			DataOutputStream dos = new DataOutputStream(out);						dos.writeUTF("Hey");						String s = null;						if((s = dis.readUTF()) != null) {				System.out.println(s);			}									dis.close();			dos.close();			socket.close();						} catch(UnknownHostException e) {			e.printStackTrace();		}catch(IOException e) {			e.printStackTrace();		}					}}