心得11--网络编程2-QQ、飞秋等聊天室部分网络编程

  聊天室前奏：先来些辅助工作，通过四个案例慢慢深入了解聊天室的内幕，下期与大家分享聊天室的编写

1.案例一：发送端

packagecom.packet;

importjava.net.DatagramPacket;

importjava.net.DatagramSocket;

importjava.net.InetAddress;

publicclass SendDemo {

   public static void main(String[] args) throwsException {

      //建立UPDSocket

      DatagramSocket ds = new DatagramSocket();

      //建立数据包

      byte[] buf = "I am a guy!!".getBytes();

      DatagramPacket dp = newDatagramPacket(buf,buf.length,InetAddress.getByName("192.168.49.255"),9009);

      //发送

      ds.send(dp);

      //关闭

      ds.close();

   }

}

 

2. 
案例二：接收端

packagecom.packet;

importjava.net.DatagramPacket;

importjava.net.DatagramSocket;

publicclass ReceiveDemo {

   public static void main(String[] args) throwsException {

      //建立UPDSocket

      DatagramSocket ds = newDatagramSocket(9009);

      //建立数据包

      byte[] buf = new byte[1024];

      DatagramPacket dp = newDatagramPacket(buf,buf.length);

      //接收

      ds.receive(dp);

      //通过数据包对象的方法接收数据

      String ip =dp.getAddress().getHostAddress();

      String date = newString(dp.getData(),0,dp.getLength());

      int port = dp.getPort();  //获取端口

      System.out.println(ip+":"+date+":"+port);

      //关闭

      ds.close();

   }

}

3．  可以键盘录入的发送端

packagecom.packet;

importjava.io.BufferedReader;

importjava.io.InputStreamReader;

importjava.net.DatagramPacket;

importjava.net.DatagramSocket;

importjava.net.InetAddress;

publicclass SendDemo1 {

   public static void main(String[] args) throwsException {

      //建立UPDSocket

      DatagramSocket ds = new DatagramSocket();

      //建立数据包

      BufferedReader br = new BufferedReader(newInputStreamReader(System.in));

      String line = null;

      while((line=br.readLine())!=null){       

        byte[] buf = line.getBytes();

        DatagramPacket dp = newDatagramPacket(buf,buf.length,InetAddress.getByName("192.168.49.255"),9009);

        //发送

        if(line.equals("886")){

           ds.send(dp);break;

        }

        ds.send(dp);

      }

      //关闭

      ds.close();

   }

}

4.可以无限接收的接收端

packagecom.packet;

importjava.net.DatagramPacket;

importjava.net.DatagramSocket;

publicclass ReceiveDemo1 {

   /**

    * 无限接收消息，当接收的是886时退出程序

    * 接收端口;与前例不同这里没有IP的输出而是换成特定字符串；

    * @throwsIOException

    */

   public static void main(String[] args) throwsException {

      //建立UPDSocket

      DatagramSocket ds = newDatagramSocket(9009);

      //建立数据包

      while(true){       

        byte[] buf = new byte[1024];

        DatagramPacket dp = newDatagramPacket(buf,buf.length);

        //发送

        ds.receive(dp); 

        String ip =dp.getAddress().getHostAddress();

        String date = newString(dp.getData(),0,dp.getLength());

        int port = dp.getPort();  //获取端口

        if(date.equals("886")){

           System.out.println(ip+":"+date+":"+port);break;

        }

        System.out.println(ip+":"+date+":"+port);

      }

      //关闭

      ds.close();

   }

}