我有一个 Express 服务器，用于监听来自外部 API 的 webhook 事件。当它收到这些事件时，我希望该 http 请求的处理程序向 WebSocket 客户端发送一条消息。这是一些基本代码来说明我的意思
外部 API 将向我的 Express 服务器上的端点发送 HTTP POST 请求，可以说它看起来像这样:

app.post('/external-api', (req, res) => {

    // webhook payload will be in req.body
})

hiện hữu /external-api 的处理程序中我想向通过 WebSocket 连接到服务器的客户端发送消息。截至目前，我正在使用 npm ws库，所以我希望逻辑看起来像这样

app.post('/external-api', (req, res) => {

    ws.broadcast(req.body);
})

有没有办法做到这一点？我愿意使用其他库，但我只需要一种方法来从 Express 中的 HTTP POST 请求处理程序向 WebSocket 客户端发送消息。

1 Câu trả lời

Sau đây là một ví dụ:index.ts :

import express from 'express';
import WebSocket from 'ws';
import http from 'http';
import path from 'path';
import faker from 'faker';

const app = express();
const port = 3000;
const server = http.createServer(app);
const wss = new WebSocket.Server({ server });

wss.on('connection', (ws: WebSocket) => {
  console.log('establish websocket connection');
  ws.on('message', (message) => {
    console.log('received: %s', message);
  });
});

app.get('/client/:id', (req, res) => {
  res.sendFile(path.resolve(__dirname, `./public/client-${req.params.id}.html`));
});

app.get('/external-api', (req, res) => {
  wss.clients.forEach((client) => {
    if (client.readyState === WebSocket.OPEN) {
      client.send(faker.internet.email());
    }
  });
  res.sendStatus(200);
});

server.listen(port, () => console.log(`http server is listening on http://localhost:${port}`));

client-1.html :

  <đầu>
    
    
    
  
  
    
client 1

    Test
    
      (chức năng() {
        window.onload = function() {
          const socket = new WebSocket('ws://localhost:3000');

          // Connection opened
          socket.addEventListener('open', function(event) {
            socket.send('Hello Server! Client - 1');
          });

          // Listen for messages
          socket.addEventListener('message', function(event) {
            console.log('Message from server ', event.data);
          });

          const btn = document.getElementById('test');
          btn.addEventListener('click', async () => {
            thử {
              const res = await fetch('http://localhost:3000/external-api');
              console.log(res);
            } catch (error) {
              console.log(error);
            }
          });
        };
      })();
    
  

client-2.html :

  <đầu>
    
    
    
  
  
    
client 2

    Test
    
      (chức năng() {
        window.onload = function() {
          const socket = new WebSocket('ws://localhost:3000');

          // Connection opened
          socket.addEventListener('open', function(event) {
            socket.send('Hello Server! Client - 2');
          });

          // Listen for messages
          socket.addEventListener('message', function(event) {
            console.log('Message from server ', event.data);
          });

          const btn = document.getElementById('test');
          btn.addEventListener('click', async () => {
            thử {
              const res = await fetch('http://localhost:3000/external-api');
              console.log(res);
            } catch (error) {
              console.log(error);
            }
          });
        };
      })();
    
  

现在，点击客户端 1 的按钮，发送 HTTP 请求到 /external-api .
客户端 1 的控制台日志:

客户端 2 的控制台日志:

服务器的日志:

http server is listening on http://localhost:3000
establish websocket connection
received: Hello Server! Client - 1
establish websocket connection
received: Hello Server! Client - 2

如您所见，服务器向客户端 1 和客户端 2 广播虚假电子邮件。

关于node.js - 在 express 中从 POST 请求处理程序发送 WebSocket 消息，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/63099518/