UDP client,UDP server, TCP server, TCP client

UDP server

 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.InetSocketAddress;
 import java.net.SocketException;

 /**
  * udpserver
  * 监听端口 10001
  * @author GXF
  *
  */
 public class UdpSocketServer {
     private DatagramSocket serverSocket;

     public UdpSocketServer(int port){
         init(port);
     }

     public void init(int port){

         InetSocketAddress serverSocketAddress = new InetSocketAddress( port);
         try {
             serverSocket = new DatagramSocket(serverSocketAddress);
         } catch (SocketException e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

     //监听端口
     public void startListen(){
         byte buff[] = new byte[1024];
         DatagramPacket receivePacket = new DatagramPacket(buff, buff.length);
         while(true){
             try {
                 serverSocket.receive(receivePacket);
                 String message = new String(buff, 0, receivePacket.getLength());
                 System.out.println("message from client = " + message);
             } catch (IOException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
         }
     }

     public static void main(String args[]){
         UdpSocketServer udpSocketServer = new UdpSocketServer(10001);
         udpSocketServer.startListen();
     }
 }

UDP client

 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.InetAddress;
 import java.net.InetSocketAddress;
 import java.net.SocketException;
 import java.net.UnknownHostException;

 /**
  * Udp客户端  DatagramSocket
  * @author GXF
  *
  */
 public class UdpSocketClient {
     //客户端套接字
     private DatagramSocket clientSocket;

     //构造方法
     public UdpSocketClient(String ip, int port){
         init(ip, port);
     }

     /**
      * 初始化套接字
      * @param ip
      * @param port
      */
     public void init(String ip, int port){
 //        try {
 //            InetAddress serverAddress = InetAddress.getByName(ip);
 //            InetSocketAddress serverSocketAddress = new InetSocketAddress(serverAddress, port);
             try {
                 clientSocket = new DatagramSocket();
             } catch (SocketException e) {
                 // TODO Auto-generated catch block
                 e.printStackTrace();
             }
 //        } catch (UnknownHostException | SocketException e) {
 //            e.printStackTrace();
 //        }
     }

     /**
      * 使用UDP向服务器发送消息
      * @param ip
      * @param message
      */
     public void sendMessage(String message){
         byte buff[] = message.getBytes();
         DatagramPacket packetToSend;
         try {
             packetToSend = new DatagramPacket(buff, buff.length, InetAddress.getByName("127.0.0.1"), 10002);
             clientSocket.send(packetToSend);                                                    //发送数据包
         } catch (Exception e) {
             // TODO Auto-generated catch block
             e.printStackTrace();
         }
     }

     public static void main(String[] args) {
         String serverIp = "127.0.0.1";
         int port = 10001;
         UdpSocketClient clientSocket = new UdpSocketClient(serverIp, port);
         String message = "hahahahah";
         clientSocket.sendMessage(message);

     }

 }

TCP server

import java.io.IOException;
import java.io.InputStream;
import java.net.ServerSocket;
import java.net.Socket;

public class TcpServer {
    private ServerSocket serverSocket;

    TcpServer(int port){
        try {
            serverSocket = new ServerSocket(port);
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

    //开始监听端口
    public void start(){
        while(true){
            try {
                Socket clientSocket = serverSocket.accept();
                InputStream is = clientSocket.getInputStream();
                byte buff[] = new byte[1024];
                int length = -1;
                StringBuilder sb = new StringBuilder();
//                while((length = is.read(buff)) > 0){
                length = is.read(buff);
                    sb.append(new String(buff, 0, length));
//                }//while
                System.out.println("message received: " + sb.toString());
                clientSocket.close();
            } catch (IOException e) {
                e.printStackTrace();
            }

        }
    }

    public static void main(String args[]){
        int port = 10002;
        TcpServer tcpServer = new TcpServer(port);
        tcpServer.start();
    }
}

Tcp client

 import java.io.IOException;
 import java.io.OutputStream;
 import java.net.InetAddress;
 import java.net.Socket;
 import java.util.Scanner;

 public class TcpClient {
     private Socket socket;
     private int port;

     private TcpClient(int port){
 //        try {
             this.port = port;
 //        } catch (IOException e) {
 //            e.printStackTrace();
 //        }
     }

     /**
      * 发送消息
      * @param message
      */
     public void sendMessage(String message){
         try {
             Socket socket = new Socket(InetAddress.getByName("127.0.0.1"), port);
             OutputStream os = socket.getOutputStream();
             byte buff[] = message.getBytes();
             os.write(buff);
             os.flush();
             socket.close();
         } catch (IOException e) {
             e.printStackTrace();
         }

     }

     public void inputMessage(){
         Scanner scanner = new Scanner(System.in);
         while(true){
             String message = scanner.nextLine();
             sendMessage(message);
         }
     }

     public static void main(String[] args) {
         int port = 10001;
         TcpClient client = new TcpClient(port);
         client.inputMessage();
     }

 }