分布式通信-tcp/ip 单播

服务端

public class SingleBroadCastSocketServer {

    public static void main(String[] args) {
        ServerSocket serverSocket = null;

        try {
            serverSocket = new ServerSocket(8888); //启动一个服务
            while (true) {
                final Socket socket = serverSocket.accept(); //监听客户端接入
                System.out.println("start while");
                new Thread(new Runnable() {
                    public void run() {
                        System.out.println("start thread");
                        try {
                            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
                            PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()));

                            while (true){
                                System.out.println("read data start");
                                String clientData = bufferedReader.readLine();
                                if(clientData ==null){
                                    System.out.println("read data is null");
                                    break;
                                }

                                System.out.println("服务端接收到的数据:"+clientData);

                                printWriter.println("data from server");
                                printWriter.flush();
                            }
                        } catch (IOException e) {
                            e.printStackTrace();
                        }

                    }
                }).start();
            }
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(serverSocket!=null){
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }

}

客户端

/**
 *  单播-客戶端
 */
public class SingleBroadCastSocketClient {

    public static void main(String[] args) {
        try {
            Socket socket = new Socket("localhost", 8888);
            BufferedReader reader = new BufferedReader(new InputStreamReader(socket.getInputStream()));//读取服务端数据
            PrintWriter printWriter = new PrintWriter(socket.getOutputStream(), true);  //往服务器写数据
            System.out.println("client set data");

            //printWriter.write("data from client");
            //write()方法，本身不会写入换行符，如果用write()写入了信息，在另一端如果用readLine()方法。由于读不到换行符，意味中读不到结束标记，然后由于IO流是阻塞式的，所以程序就是一直卡在那里不动了。原因即为缺少回车标识。如果在写入的时候加上“\r\n”,就可以解决这个问题了。而println()就自动加上了换行符了。

            printWriter.println("data from client");
            while (true){
                System.out.println("client rec data");
                String serverData = reader.readLine();
                System.out.println("client rec data start");
                if(serverData==null){
                    break;
                }
                System.out.println("客户端收到数据："+serverData);
            }
            printWriter.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}