一、WebSocket简介

• WebSocket协议是基于TCP的一种新的网络协议。它实现了浏览器与服务器全双工（full-duplex）通信，即允许服务器主动发送信息给客户端。因此，在WebSocket中，浏览器和服务器只需要完成一次握手，两者之间就直接可以创建持久性的连接，并进行双向数据传输，客户端和服务器之间的数据交换变得更加简单。

二、WebSocket服务端代码示例

• 服务端示例代码

  package com.worklite.out.socket;
  
  import lombok.extern.slf4j.Slf4j;
  import java.io.*;
  import java.net.ServerSocket;
  import java.net.Socket;
  
  /**
   * @description:
   * @author: xz
   */
  @Slf4j
  public class SocketServer extends Thread{
      Socket socket = null;
  
      public SocketServer(Socket socket) {
          this.socket = socket;
      }
  
      @Override
      public void run() {
          BufferedReader bufferedReader = null;
          PrintWriter writer = null;
          try {
              bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
              //true,表示自动刷新，不需要人为触发
              writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()), true);
  
              String userInput;
              while ((userInput = bufferedReader.readLine()) != null) {
                  if ("exit".equals(userInput)) {
                      log.info("短信socket服务端退出连接通信\t");
                      break;
                  }
                  log.info("短信socket服务端 接收内容：\t" + userInput);
                  String result = "<?xml version=\"1.0\" encoding=\"utf-8\"?><response>0000</response>";
                  writer.println(result);
              }
          } catch (IOException e) {
              e.printStackTrace();
          } finally {
              try {
                  if (writer != null){
                      writer.close();
                  }
                  if (bufferedReader != null) {
                      bufferedReader.close();
                  }
                  if (socket != null) {
                      socket.close();
                  }
              } catch (IOException ioException) {
                  ioException.printStackTrace();
              }
          }
      }
  
      public static void main(String[] args) {
          try {
              //1.创建服务器端ServerSocket对象，指定端口
              ServerSocket serverSocket = new ServerSocket(64202);
              Socket socket = null;
              log.info("短信socket服务端等待客户端的连接");
              //2.调用accept()监听（即等待客户端的连接）
              while (true) {
                  socket = serverSocket.accept();
                  //创建一个新线程
                  SocketServer serverThread = new SocketServer(socket);
                  serverThread.start();
              }
          } catch (IOException e) {
              e.printStackTrace();
          }
      }
  
  }
  

三、WebSocket客户端代码示例

• 客户端示例代码

  package com.worklite.out.socket;
  
  import lombok.extern.slf4j.Slf4j;
  import java.io.*;
  import java.net.Socket;
  /**
   * @description:
   * @author: xz
   */
  @Slf4j
  public class SocketClient {
  
      public static String client(String reqXmlStr,String socketIp,int socketPort) {
          log.info("调用短信socket客户端，xml格式请求报文——>{}",reqXmlStr);
          Socket socket = null;
          BufferedReader bufferedReader = null;
          PrintWriter writer = null;
          String result = null;
          try {
              socket = new Socket(socketIp,socketPort);
  
              //发送数据到服务端
              writer = new PrintWriter(new OutputStreamWriter(socket.getOutputStream()), true);
              writer.println(reqXmlStr);
  
              //接收服务端返回数据流
              bufferedReader = new BufferedReader(new InputStreamReader(socket.getInputStream()));
              while ((result = bufferedReader.readLine()) != null){
                  log.info("短信socket客户端接收服务端响应报文：{}",result);
                  //退出指令，关闭连接
                  writer.println("exit");
                  break;
              }
          }catch (IOException e) {
              log.info("[短信socket客户端异常]",e);
              e.printStackTrace();
          } finally {
              try {
                  if (writer != null){
                      writer.close();
                  }
                  if (bufferedReader != null) {
                      bufferedReader.close();
                  }
                  if (socket != null) {
                      socket.close();
                  }
              } catch (IOException e) {
                  log.info("[短信socket客户端流关闭异常]",e);
                  e.printStackTrace();
              }
          }
          return result;
      }
  
      public static void main(String[] args) {
          String reqXmlStr="<?xml version=\"1.0\" encoding=\"utf-8\"?><request><telnumber>13912345678</telnumber></request>";
          client(reqXmlStr,"localhost",64202);
      }
  
  }
  

四、运行服务端和客户端，查看输出结果

• 先启动服务端，如下图所示：
  
• 再启动客户端，如下图所示：
  
• 再次查看服务端，如下图所示：