package com.sjf;import java.io.IOException;import java.net.DatagramPacket;import java.net.DatagramSocket;import java.net.InetAddress;import java.net.InetSocketAddress;import java.net.SocketException;/** * @time 2015-05-27 * @desc UDP通信 * @author sjf0115 * */public class Server {
             private byte[] buffer = new byte[1024];        private DatagramSocket socket = null;        private DatagramPacket packet = null;        private InetSocketAddress socketAddress = null;        private InetAddress clientAddress;    private String clientIP;    private int clientPort;    private String clientData;    //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 构造函数，绑定主机和端口.       * @param ip  IP 地址     * @param port 端口       * @throws Exception       */        public Server(String ip, int port) throws Exception     {            // 绑定IP地址和端口.         Bind(ip,port);         System.out.println("[服务端启动]");        }    //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    public Server() throws SocketException    {        // 构造数据报套接字并将其绑定到本地主机上任何可用的端口        socket = new DatagramSocket();            System.out.println("[服务端启动]");        }  //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 绑定监听地址和端口.       * @param ip IP地址       * @param port 端口       * @throws SocketException       */        public void Bind(String ip, int port) throws SocketException {            // 根据 IP 地址和端口号创建套接字地址        socketAddress = new InetSocketAddress(ip, port);          // 创建数据报套接字，将其绑定到指定的本地地址        socket = new DatagramSocket(socketAddress);        packet = new DatagramPacket(buffer, buffer.length);    }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    public final String getOrgIp()     {            return clientIP;        }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 设置超时时间       * @param timeout 超时时间       * @throws Exception       */        public void SetTimeout(int timeout) throws Exception     {            /* 启用/禁用带有指定超时值的 SO_TIMEOUT，以毫秒为单位。         * 将此选项设为非零的超时值时，对此 DatagramSocket 调用 receive() 将只阻塞此时间长度。         * 如果超过超时值，将引发 java.net.SocketTimeoutException，虽然 DatagramSocket 仍旧有效。         * 选项必须在进入阻塞操作前被启用才能生效。         */        socket.setSoTimeout(timeout);        }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 获得超时时间.       * @return 返回超时时间.       * @throws Exception       */        public int GetTimeout() throws Exception     {            return socket.getSoTimeout();        }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 接收数据包，该方法会造成线程阻塞.       * @return 返回接收的数据串信息       * @throws IOException        */        public String Receive() throws IOException     {            /*         * 从此套接字接收数据报包。当此方法返回时，DatagramPacket 的缓冲区填充了接收的数据。         * 数据报包也包含发送方的 IP 地址和发送方机器上的端口号。此方法在接收到数据报前一直阻塞。         * 数据报包对象的 length 字段包含所接收信息的长度。如果信息比包的长度长，该信息将被截短。         */        socket.receive(packet);        // 数据报包包含发送方的 IP 地址        clientAddress = packet.getAddress();        clientIP = clientAddress.getHostAddress();        // 数据报包包含发送方的端口号        clientPort = packet.getPort();        // 数据报包包含发送方的数据        clientData = new String(packet.getData(), 0, packet.getLength());             return " ["+clientData+"]";        }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 将响应包发送给请求端.       * @param bytes 回应报文       * @throws IOException       */        public void Send(String info) throws IOException     {            packet.setAddress(clientAddress);        packet.setPort(clientPort);        packet.setData(info.getBytes());         /*         * 从此套接字发送数据报包。DatagramPacket 包含的信息指示：将要发送的数据、其长度、远程主机的 IP 地址和远程主机的端口号。         */        socket.send(packet);        }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 关闭udp监听口.       */        public void close()     {            try         {                socket.close();            }         catch (Exception ex)         {                ex.printStackTrace();            }        }        //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**       * 测试方法.       * @param args       * @throws Exception       */        public static void main(String[] args) throws Exception {            String serverHost = "127.0.0.1";            int serverPort = 3344;            Server udpServerSocket = new Server(serverHost, serverPort);            while (true)         {                String info = udpServerSocket.Receive();              System.out.println("["+udpServerSocket.clientPort+"]->"+info);            udpServerSocket.Send("Reponse-----"+info);            }        }    }

package com.sjf;import java.io.*;  import java.net.*;  /**  * @time 2015-05-27 * @desc UDP通信 * @author QPING */  public class Client {
           private byte[] buffer = new byte[1024];      private DatagramSocket socket = null;      private InetSocketAddress socketAddress = null;        private String clientIP;    private int clientPort;    private String clientData;    private InetAddress clientAddress;    private DatagramPacket sendPacket;    private DatagramPacket receivePacket;    //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    public Client(String host, int port) throws Exception     {             // 根据 IP 地址和端口号创建套接字地址        socketAddress = new InetSocketAddress(host, port);          // 创建数据报套接字，将其绑定到指定的本地地址        socket = new DatagramSocket(socketAddress);            System.out.println("服务端启动!");        }    //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**      * 构造函数，创建UDP客户端      * @throws Exception      */      public Client() throws Exception     {          socket = new DatagramSocket();      }      //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++      /**      * 设置超时时间，该方法必须在bind方法之后使用.      * @param timeout 超时时间      * @throws Exception      */      public final void SetTimeout(final int timeout) throws Exception     {          socket.setSoTimeout(timeout);      }      //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**      * 获得超时时间.      * @return 返回超时时间      * @throws Exception      */      public int GetTimeout() throws Exception     {          return socket.getSoTimeout();      }    //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    public DatagramSocket GetSocket()     {          return socket;      }      //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**      * 向指定的服务端发送数据信息.      * @param ip 服务器主机地址      * @param port 服务端端口      * @param bytes 发送的数据信息      * @return 返回构造后俄数据报      * @throws IOException      */      public DatagramPacket Send(String ip,int port,String info) throws IOException     {          byte[] bytes = info.getBytes();        sendPacket = new DatagramPacket(bytes, bytes.length);        sendPacket.setAddress(InetAddress.getByName(ip));        sendPacket.setPort(port);        socket.send(sendPacket);          return sendPacket;      }      //+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**      * 接收从指定的服务端发回的数据.      * @param lhost 服务端主机      * @param lport 服务端端口      * @return 返回从指定的服务端发回的数据.      * @throws Exception      */      public String Receive(String lhost,int lport)   throws Exception     {          receivePacket = new DatagramPacket(buffer, buffer.length);          socket.receive(receivePacket);          // 数据报包包含发送方的 IP 地址        clientAddress = receivePacket.getAddress();        clientIP = clientAddress.getHostAddress();        // 数据报包包含发送方的端口号        clientPort = receivePacket.getPort();        // 数据报包包含发送方的数据        clientData = new String(receivePacket.getData(), 0, receivePacket.getLength());             return "["+clientData+"]";     }      //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**      * 关闭udp连接.      */      public void close()     {          try         {              socket.close();          }         catch (Exception ex)         {              ex.printStackTrace();          }      }      //++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++    /**      * 测试客户端发包和接收回应信息的方法.      * @param args      * @throws Exception      */      public static void main(String[] args) throws Exception {          String serverHost = "127.0.0.1";          int serverPort = 3344;        String myIP = "127.0.0.2";        int myPort = 3333;        Client client = new Client(myIP,myPort);          while(true)        {            BufferedReader br = new BufferedReader(new InputStreamReader(System.in));            System.out.println("["+myPort+"] ");            String str = br.readLine();            client.Send(serverHost, serverPort, str);            String info = client.Receive(serverHost, serverPort);              System.out.println("["+client.clientPort+"]->" + info);          }    }  }