在内部发出另一个HTTP请求后，发送HTTP响应时出错：“发送后无法设置标题”

Question

I'm getting the following error when I send http response, in an express.js in Node.js, after making another http request inside my server.

Error: Can't set headers after they are sent.
_http_outgoing.js:491
    at validateHeader (_http_outgoing.js:491:11)
    at ServerResponse.setHeader (_http_outgoing.js:498:3)
    at ServerResponse.header (/home/gustavo/Programacao/node-js/Imobiliaria/node_modules/express/lib/response.js:767:10)
    at ServerResponse.json (/home/gustavo/Programacao/node-js/Imobiliaria/node_modules/express/lib/response.js:264:10)
    at Request._callback (/home/gustavo/Programacao/node-js/Imobiliaria/api/controllers/property.js:71:41)
    at Request.self.callback (/home/gustavo/Programacao/node-js/Imobiliaria/node_modules/request/request.js:185:22)
    at emitTwo (events.js:126:13)
    at Request.emit (events.js:214:7)
    at Request.<anonymous> (/home/gustavo/Programacao/node-js/Imobiliaria/node_modules/request/request.js:1161:10)
    at emitOne (events.js:116:13)

Here is my code:

var request = require('request');
// ...
// Making http request
request(utils.url('/api/property-photos/' + propertyId), function (error, response, body) {
    // ...
    res.status(200).json({}).end(); // For tests
    // ...
});

I think that the request is sending some response to my server'se response, but I can't figure out why and how.

I'd like to antecipate my thanks for who can help me. ;)

Answer 1

request package is only to make request and to get response.So you can not send res.send() Usually this error caused when you send res(response) 2 or more times

example to cause same problem.

route.get('/app',(req,res)=>{
 res.send()
 res.send()
})

Check in your code if something like this is present.

Answer 2

Thank you for helping me :D

I've just found the issue. The http request I'm making inside my server current request does it asynchronously. So after calling it, I was calling res.end() , before I send a response to my server request. This response I am sending inside the other http request results.