提供一个微信小程序和springboot长链接，后端IP是 192.168.124.20 端口号是8090，写一个微信小程序的demo，可以互相发送信息

微信小程序端可以使用wx.requestSocket进行websocket长链接通信，后端使用SpringBoot的WebSocket进行处理。以下是一个简单的demo：

1. 微信小程序端代码

//index.js
Page({
  data: {
    message: '',
    socketOpen: false,
    inputValue: ''
  },
  onLoad: function () {
    wx.connectSocket({
      url: 'ws://192.168.124.20:8090/ws',
    })

    wx.onSocketOpen((res) => {
      console.log('WebSocket连接已打开！')
      this.setData({ socketOpen: true })
    })

    wx.onSocketMessage((res) => {
      console.log('收到服务器内容：' + res.data)
      this.setData({ message: res.data })
    })

    wx.onSocketClose((res) => {
      console.log('WebSocket连接已关闭！')
      this.setData({ socketOpen: false })
    })

    wx.onSocketError((res) => {
      console.log('WebSocket连接打开失败，请检查！')
    })
  },

  sendMessage: function() {
    if (!this.data.inputValue) {
      wx.showToast({
        title: '请输入内容',
        icon: 'none'
      })
      return
    }

    if (this.data.socketOpen) {
      wx.sendSocketMessage({
        data: this.data.inputValue,
        success: () => {
          console.log('发送成功！')
        }
      })
      this.setData({ inputValue: '' })
    } else {
      wx.showToast({
        title: '连接已断开！',
        icon: 'none'
      })
    }
  },

  inputHandler: function(e) {
    this.setData({ inputValue: e.detail.value })
  }
})

2. SpringBoot端代码

WebSocketConfig.java

@Configuration
@EnableWebSocket
public class WebSocketConfig implements WebSocketConfigurer {
    @Override
    public void registerWebSocketHandlers(WebSocketHandlerRegistry registry) {
        registry.addHandler(myHandler(), "/ws")
                .setAllowedOrigins("*");
    }

    @Bean
    public WebSocketHandler myHandler() {
        return new MyHandler();
    }
}

MyHandler.java

public class MyHandler implements WebSocketHandler {
    private static final List<WebSocketSession> sessions = new ArrayList<>();

    @Override
    public void afterConnectionEstablished(WebSocketSession session) throws Exception {
        sessions.add(session);
        System.out.println("新连接加入，当前在线人数：" + sessions.size());
    }

    @Override
    public void handleMessage(WebSocketSession session, WebSocketMessage<?> message) throws Exception {
        String msg = message.getPayload().toString();
        System.out.println("收到信息：" + msg);
        for (WebSocketSession s : sessions) {
            s.sendMessage(new TextMessage(msg));
        }
    }

    @Override
    public void handleTransportError(WebSocketSession session, Throwable exception) throws Exception {
        if (session.isOpen()) {
            session.close();
        }
        sessions.remove(session);
        System.out.println("连接错误，当前在线人数：" + sessions.size());
    }

    @Override
    public void afterConnectionClosed(WebSocketSession session, CloseStatus closeStatus) throws Exception {
        sessions.remove(session);
        System.out.println("连接关闭，当前在线人数：" + sessions.size());
    }

    @Override
    public boolean supportsPartialMessages() {
        return false;
    }
}

这个demo是一个简单的群聊，所有连接到服务器的客户端都会收到其他客户端发送的信息。如果需要实现点对点聊天，可以在MyHandler中对消息进行处理，只向指定的客户端发送消息。