node.js Node Express 发送图像文件作为 API 响应
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Node Express sending image files as API response
提问by metalaureate
I Googled this but couldn't find an answer but it must be a common problem. This is the same question as Node request (read image stream - pipe back to response), which is unanswered.
我用谷歌搜索了这个，但找不到答案，但这一定是一个常见问题。这是与Node request (read image stream - pipe back to response)相同的问题，没有回答。
How do I send an image file as an Express .send() response? I need to map RESTful urls to images - but how do I send the binary file with the right headers? E.g.,
如何将图像文件作为 Express .send() 响应发送？我需要将 RESTful url 映射到图像 - 但是如何发送带有正确标题的二进制文件？例如，
<img src='/report/378334e22/e33423222' />
Calls...
打电话...
app.get('/report/:chart_id/:user_id', function (req, res) {
//authenticate user_id, get chart_id obfuscated url
//send image binary with correct headers
});
回答by Po-Ying Chen
There is an api in Express.
Express中有一个api。
res.sendFile
res.sendFile
app.get('/report/:chart_id/:user_id', function (req, res) {
// res.sendFile(filepath);
});
回答by kharandziuk
a proper solution with streams and error handling is below:
流和错误处理的正确解决方案如下：
const fs = require('fs')
const stream = require('stream')
app.get('/report/:chart_id/:user_id',(req, res) => {
const r = fs.createReadStream('path to file') // or any other way to get a readable stream
const ps = new stream.PassThrough() // <---- this makes a trick with stream error handling
stream.pipeline(
r,
ps, // <---- this makes a trick with stream error handling
(err) => {
if (err) {
console.log(err) // No such file or any other kind of error
return res.sendStatus(400);
}
})
ps.pipe(res) // <---- this makes a trick with stream error handling
})
with Node older then 10 you will need to use pumpinstead of pipeline.
如果节点比 10 旧，您将需要使用泵而不是管道。
