如何从节点JS API返回zip文件并处理在客户端?
我有一个创建使用归档模块中,我想,传回拉链作为一个与输入反应下载客户端上的一个zip文件的API。
这就是我的API创建的zip的样子:
reports.get('/xxx/:fileName', async (req, res) => {
var s3 = new AWS.S3();
var archiver = require('archiver');
var filenames = "xxx"
var str_array = filenames.split(',');
for (var i = 0; i < str_array.length; i++) {
var filename = str_array[i].trim();
localFileName = './temp/' + filename.substring(filename.indexOf("/") + 1);
file = fs.createWriteStream(localFileName, {flags: 'a', encoding: 'utf-8',mode: 0666});
file.on('error', function(e) { console.error(e); });
s3.getObject({
Bucket: config.xxx,
Key: filename
})
.on('error', function (err) {
console.log(err);
})
.on('httpData', function (chunk) {
file.on('open', function(){
file.write(chunk);
});
})
.on('httpDone', function () {
file.end();
})
.send();
}
res.end("Files have been downloaded successfully")
// create a file to stream archive data to.
var output = fs.createWriteStream('example.zip');
var archive = archiver('zip', {
zlib: { level: 9 } // Sets the compression level.
});
// listen for all archive data to be written
// 'close' event is fired only when a file descriptor is involved
output.on('close', function() {
console.log(archive.pointer() + ' total bytes');
console.log('archiver has been finalized and the output file descriptor has closed.');
});
// This event is fired when the data source is drained no matter what was the data source.
// It is not part of this library but rather from the NodeJS Stream API.
// @see: .html#stream_event_end
output.on('end', function() {
console.log('Data has been drained');
});
// good practice to catch warnings (ie stat failures and other non-blocking errors)
archive.on('warning', function(err) {
if (err.code === 'ENOENT') {
// log warning
} else {
// throw error
throw err;
}
});
// good practice to catch this error explicitly
archive.on('error', function(err) {
throw err;
});
// pipe archive data to the file
archive.pipe(output);
// append files from a sub-directory, putting its contents at the root of archive
archive.directory('./temp', false);
// finalize the archive (ie we are done appending files but streams have to finish yet)
// 'close', 'end' or 'finish' may be fired right after calling this method so register to them beforehand
archive.finalize();
});
也可对照这里是我的API的另一个展示如何,我习惯将数据发送回客户端:
reports.get('/xxx/:fileName', async (req, res) => {
var s3 = new AWS.S3();
var params = {
Bucket: config.reportBucket,
Key: req.params.fileName,
Expires: 60 * 5
}
try {
s3.getSignedUrl('getObject', params, function (err, url) {
if(err)throw err;
res.json(url);
});
}catch (err) {
res.status(500).send(err.toString());
}
});
我怎样才能拉链发回的响应,并下载客户端上的磁盘?
回答如下:由于archive
是流,我会假设它可以是管(内衬)直接连接到响应(res
):
// Node.js v10+, if res is a proper stream
const {pipeline} = require('stream')
pipeline(archive, res)
// Alternatively (search for caveats of pipe vs. pipeline)
archive.pipe(res)
你或许应该设置res
的HTTP标头告诉浏览器的MIME类型和可能的文件名:
res.set({
'Content-Type': 'application/zip',
'Content-Disposition': 'attachment; filename="filename.jpg"'
})