1 Look at the client server code under a simple tcp communication:
/** 1. To create a client, you must specify the server + port to connect at this time Socket(String host, int port) 2. Receive data + send data * @author Administrator * */ public class Client { /** * @param args * @throws IOException * @throws UnknownHostException */ public static void main(String[] args) throws UnknownHostException, IOException { //1. To create a client, you must specify the server + port to connect at this time Socket client = new Socket("localhost",8888); //2, receive data /* BufferedReader br = new BufferedReader(new InputStreamReader(client.getInputStream())); String echo =br.readLine(); //Blocking method System.out.println(echo); */ DataInputStream dis = new DataInputStream(client.getInputStream()); String echo = dis.readUTF(); System.out.println(echo); } } Server: /** You must start the server before connecting 1. Create the server specified port ServerSocket(int port) 2. Receive client connections 3. Send data + receive data * */ public class Server { /** * @param args * @throws IOException */ public static void main(String[] args) throws IOException { //1. Create the server specified port ServerSocket(int port) ServerSocket server = new ServerSocket(8888); //2, receive client connection blocking Socket socket =server.accept(); System.out.println("A client establishes a connection"); //3, send data String msg = "Welcome"; //output stream /* BufferedWriter bw = new BufferedWriter( new OutputStreamWriter( socket.getOutputStream())); bw.write(msg); bw.newLine(); bw.flush(); */ DataOutputStream dos = new DataOutputStream(socket.getOutputStream()); dos.writeUTF(msg); // The server writes out data dos.flush(); } }