监听本机端口获取数据

其实就是在本机建立一个server端监听这个端口，如下

udpServer：

package TTt;


import java.net.DatagramPacket;
import java.net.DatagramSocket;
import java.net.InetAddress;


public class UDPServer {
    public static void main(String args[]) throws Exception
    {
        //监听9876端口
       DatagramSocket serverSocket = new DatagramSocket(9876);
          byte[] receiveData = new byte[1024];
          byte[] sendData = new byte[1024];
          while(true)
             {
                //构造数据包接收数据
                DatagramPacket receivePacket = new DatagramPacket(receiveData, receiveData.length);
                //接收数据
                serverSocket.receive(receivePacket);
                //解析数据
                String sentence = new String( receivePacket.getData());
                System.out.println("RECEIVED: " + sentence);
             }
    }
}

TCpServer:

package tcp;


import java.io.IOException;
import java.io.InputStreamReader;
import java.io.Reader;
import java.net.ServerSocket;
import java.net.Socket;

public class Server {
     
       public static void main(String args[]) throws IOException {
          //为了简单起见，所有的异常信息都往外抛
          int port = 8898;
          //定义一个ServerSocket监听在端口8899上
          ServerSocket server = new ServerSocket(port);
          //server尝试接收其他Socket的连接请求，server的accept方法是阻塞式的
          Socket socket = server.accept();
          //跟客户端建立好连接之后，我们就可以获取socket的InputStream，并从中读取客户端发过来的信息了。
          Reader reader = new InputStreamReader(socket.getInputStream());
          char chars[] = new char[64];
          int len;
          StringBuilder sb = new StringBuilder();
          while ((len=reader.read(chars)) != -1) {
             sb.append(new String(chars, 0, len));
          }
          System.out.println("from client: " + sb);
          
          reader.close();
          socket.close();
          server.close();
       }
       
    }