8、网络

 1 // UDP发送端
 2 public static void sendUDPMsg() throws IOException {
 3     // 建立UDP服务
 4     DatagramSocket datagramSendSocket = new DatagramSocket();
 5     // 把数据封装到数据包中
 6     String data = "UDP测试数据";
 7     // 建立数据包
 8     DatagramPacket datagramPacket = new DatagramPacket(data.getBytes(), data.getBytes().length, InetAddress.getLocalHost(), 9090);
 9     // 调用UDP的服务发送数据包
10     datagramSendSocket.send(datagramPacket);
11     // 关闭资源
12     datagramSendSocket.close();
13 }

 1 public static void reveiveUDPMsg() throws IOException{
 2     // 建立UDP服务，监听端口
 3     DatagramSocket datagramReceiveSocket = new DatagramSocket(9090);
 4     // 建立新的数据包用于存放数据
 5     byte[] buf = new byte[1024];
 6     DatagramPacket datagramReceivePacket = new DatagramPacket(buf, buf.length);
 7     // 调用UDP服务接收数据存放在数据包的buf中
 8     datagramReceiveSocket.receive(datagramReceivePacket);
 9     System.out.println("接收到的数据:"+new String(buf, 0, datagramReceivePacket.getLength()));
10     // 关闭资源
11     datagramReceiveSocket.close();
12 }

 1 // 群聊接收端
 2 public class WeChatSender extends Thread{
 3 
 4     @Override
 5     public void run() {
 6         // 不能直接抛出异常，Thread
 7         try {
 8             // 建立UDP服务
 9             DatagramSocket datagramSendSocket = new DatagramSocket();
10             // 准备数据，封装到数据包中,用BufferedReader封装可以逐行读取
11             BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(System.in));
12             // 发送数据
13             String line = null;
14             DatagramPacket datagramSendPacket = null;
15             while((line = bufferedReader.readLine())!=null) {
16                 // 把数据封装到数据包中然后发送
17                 datagramSendPacket = new DatagramPacket(line.getBytes(), line.getBytes().length, InetAddress.getByName("192.168.1.255"), 9090);
18                 // 发送数据
19                 datagramSendSocket.send(datagramSendPacket);
20             }
21             // 关闭资源
22             datagramSendSocket.close();
23         } catch (IOException e) {
24             // TODO Auto-generated catch block
25             e.printStackTrace();
26         }
27     }
28 }

 1 // 群聊接收端
 2 public class WeChatReveiver extends Thread{
 3     
 4     @Override
 5     public void run() {
 6         try {
 7             // 建立UDP服务，监听端口
 8             DatagramSocket datagramReveiveSocket = new DatagramSocket(9090);
 9             // 准备空的数据包存储数据
10             byte[] buf = new byte[1024];
11             DatagramPacket datagramReveivePacket = new DatagramPacket(buf, buf.length);
12             // 调用UDP接收数据
13             boolean flag = true;
14             while(flag) {
15                 datagramReveiveSocket.receive(datagramReveivePacket);
16                 System.out.println(datagramReveivePacket.getAddress().getHostAddress()+":"+new String(buf, 0, datagramReveivePacket.getLength()));
17             }
18             // 关闭资源
19             datagramReveiveSocket.close();  // 要是判断条件直接为true会永远执行不到
20         } catch (IOException e) {
21             // TODO Auto-generated catch block
22             e.printStackTrace();
23         }
24     }
25 }