如何在Loopback 4上流式下载文件? [英] How to stream file as download on Loopback 4?
问题描述
我正在尝试创建一个系统,该系统将从另一个站点读取文件并将其作为文件下载提供给用户. 文件大小可能从Mbs到Gbs不等.
I'm trying to create a system that would read a file from another site and serve this as a file download to the user. The file size could vary from Mbs to Gbs.
我已经使用香草nodejs创建了概念证明.
I have have already created a proof of concept using vanilla nodejs.
const app = express();
app.get('/', (req, res) => {
res.setHeader('Content-disposition', 'attachment; filename=FILENAME');
res.setHeader('Content-type', 'application/octet-stream');
http.get('URL_TO_FILE', data => {
data.pipe(res);
});
});
我想使用回送4做到这一点.这可能吗?谢谢!
I would like to do this using loopback 4. Is this possible? Thanks!
推荐答案
您可以使用 nodejs轻松完成此操作请求并使用回送4控制器. 您需要导入以下软件包:
You can do this easily with nodejs request and using the loopback 4 controllers. You need to import this packages:
var request = require('request');
var fs = require('fs');
并将此代码放入终结点方法中:
And put this code in the endpoint method:
@get('/getImage')
async retrieveImage(): Promise<any> {
let file = fs.createWriteStream(__dirname + `/file.jpg`);
console.log('the file is here: ' + file.path);
return await new Promise((resolve, reject) => {
request({
url: 'URL_TO_FILE',
headers: {
'Content-disposition': 'attachment; filename=FILENAME',
'Content-type': 'application/octet-stream',
},
gzip: true,
})
.pipe(file)
.on('finish', () => {
console.log(`The file is finished downloading.`);
resolve();
})
.on('error', (error: any) => {
reject(error);
})
}).catch(error => {
console.log(`something happened: ${error}`)
});
}
从此,您需要转到以下网址:
From this you need to go to this url:
http://localhost:3000/getImage
该文件将以"file.jpg"名称保存在您的控制器文件夹中.
And the file would be in your controllers folder with the "file.jpg" name.
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