Question

我正在处理一小段使用express的nodeJS代码。该应用程序将有效载荷作为POST接收，并将其发送到另一种方法，该方法将其提交给kafka。一旦发生这种情况，我需要返回一个响应来表示，以便它可以根据状态关闭连接（例如，返回200响应）。

// producer.js

// Defined variables
var kafka = require('kafka-node'),
    Producer = kafka.Producer;

module.exports = {

    sendToProducer: function (payload) {

        // Define our kafka settings
        var client = new kafka.KafkaClient(),
            producer = new Producer(client);

        // On producer ready
        producer.on('ready', function () {

            // Send our payload to our topic
            producer.send(payload, function (err, data) {
                console.log(data);
                // Return our response back to `app.js` so express can handle it.
            });

        });

        // On producer error
        producer.on('error', function (err) {
            console.log('Producer Error', err)
        })
    }

};



// app.js
app.post('/payload', function (req, res) {

    // Define our route
    const payload = req.body;
    const route = payload.route;

    // Check to see if we have a route
    if(!route){
        logError('no route');
    }

    let mappedData = [{ topic: 'test', messages: 'hi... ', partition: 0 }]

    // Based on the route
    switch(route){

        // Receive data
        case 'ingest':
            producer.sendToProducer(mappedData);
            // How can I tell express the status of the above method so that we can close the request? (ex 200 response for example?)
        break;

        // Handle undefined routes
        default:

        break;
    }

});

在我的app.js案例陈述中，如何等待producer.sendToProducer(mappedData);的响应/回叫，以便我可以适当地处理快递状态？

Answer 1

确保您的sendToProducer()是promise / async函数：

app.post('/payload', async function (req, res) {

    // Define our route
    const payload = req.body;
    const route = payload.route;

    // Check to see if we have a route
    if(!route){
        logError('no route');
    }

    let mappedData = [{ topic: 'test', messages: 'hi... ', partition: 0 }]

    // Based on the route
    switch(route){

        // Receive data
        case 'ingest':
            await producer.sendToProducer(mappedData);
            // How can I tell express the status of the above method so that we can close the request? (ex 200 response for example?)
        break;

        // Handle undefined routes
        default:

        break;
    }

});

NodeJS-如何表达等待响应？

1 个答案: