/**
 * 单播
 */
public class SocketServer {
    public static void main(String[] args) {
        ServerSocket serverSocket = null;
        try {
            serverSocket = new ServerSocket(8888);
            Socket socket = serverSocket.accept(); //监听客户端
            System.out.println("start server");
            //从buffer读取内容
            BufferedReader bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
            System.out.println(bufferedReader.readLine());
            bufferedReader.close();
        } catch (IOException e) {
            e.printStackTrace();
        }finally {
            if(serverSocket!=null){
                try {
                    serverSocket.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }

    }
}

public class SocketClient {
    public static void main(String[] args) {
        try {
            Socket socket = new Socket("localhost", 8888);
            PrintWriter printWriter = new PrintWriter(socket.getOutputStream(), true);
            System.out.println("start client");
            printWriter.print("hello");
            printWriter.close();
            socket.close();
        } catch (IOException e) {
            e.printStackTrace();
        }

    }
}