Update:
我相信这could是因为我使用的是express提供的body解析器。这是否会扰乱多方试图解析的流？
我的解决方案基于这个答案 https://stackoverflow.com/a/15830910/971592.
我正在尝试做的事情：使用我的 NodeJS 服务器作为代理（出于安全目的），将文件从客户端浏览器直接流式传输到 S3。我不希望文件接触服务器的文件系统以避免出现瓶颈。
我收到以下错误：
events.js:72
throw er; // Unhandled 'error' event
^
Error: stream ended unexpectedly
at Form.<anonymous> (/Users/kentcdodds/Developer/bucketstreams/node_modules/multiparty/index.js:619:24)
at Form.EventEmitter.emit (events.js:117:20)
at finishMaybe (/Users/kentcdodds/Developer/bucketstreams/node_modules/multiparty/node_modules/readable-stream/lib/_stream_writable.js:443:14)
at endWritable (/Users/kentcdodds/Developer/bucketstreams/node_modules/multiparty/node_modules/readable-stream/lib/_stream_writable.js:452:3)
at Form.Writable.end (/Users/kentcdodds/Developer/bucketstreams/node_modules/multiparty/node_modules/readable-stream/lib/_stream_writable.js:419:5)
at onend (_stream_readable.js:457:10)
at process._tickCallback (node.js:415:13)
我查看了代码，似乎不太明白导致问题的原因。我在用着角度文件上传 https://github.com/danialfarid/angular-file-upload因为我在前端使用 Angular 。该请求如下所示：
Request URL:http://local.bucketstreams.com:3000/upload/image
Request Headers CAUTION: Provisional headers are shown.
Accept:application/json, text/plain, */*
Cache-Control:no-cache
Content-Type:multipart/form-data; boundary=----WebKitFormBoundaryNKuH2H9IUB7kvmea
Origin:http://local.bucketstreams.com:3000
Pragma:no-cache
Referer:http://local.bucketstreams.com:3000/getting-started
User-Agent:Mozilla/5.0 (Macintosh; Intel Mac OS X 10_9_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/32.0.1700.107 Safari/537.36
Request Payload
------WebKitFormBoundaryNKuH2H9IUB7kvmea
Content-Disposition: form-data; name="type"
profile
------WebKitFormBoundaryNKuH2H9IUB7kvmea
Content-Disposition: form-data; name="user"
pie
------WebKitFormBoundaryNKuH2H9IUB7kvmea
Content-Disposition: form-data; name="file0"; filename="Screen Shot 2014-02-18 at 10.54.06 PM.png"
Content-Type: image/png
------WebKitFormBoundaryNKuH2H9IUB7kvmea--
这是我的代码的样子：
var ErrorController = require('../controller/ErrorController');
var AuthenticationController = require('../controller/AuthenticationController');
var logger = require('winston');
var http = require('http');
var util = require('util');
var multiparty = require('multiparty');
var knox = require('knox');
var Batch = require('batch');
var s3Client = knox.createClient({
secure: false,
key: process.env.S3_KEY,
secret: process.env.S3_SECRET,
bucket: process.env.S3_BUCKET_IMAGES
});
var Writable = require('readable-stream').Writable;
util.inherits(ByteCounter, Writable);
function ByteCounter(options) {
Writable.call(this, options);
this.bytes = 0;
}
ByteCounter.prototype._write = function(chunk, encoding, cb) {
this.bytes += chunk.length;
cb();
};
var supportedTypes = {
profile: true,
post: true
};
module.exports = function(app) {
app.post('/upload/image', AuthenticationController.checkAuthenticated, function(req, res) {
var type = req.body.type;
var userId = req.user._id;
if (!supportedTypes[type]) {
return ErrorController.sendErrorJson(res, 401, 'Unsupported image upload type: ' + type);
}
var headers = {
'x-amz-acl': 'public-read'
};
var form = new multiparty.Form();
var batch = new Batch();
batch.push(function(cb) {
form.on('field', function(name, value) {
if (name === 'path') {
var destPath = value;
if (destPath[0] !== '/') destPath = '/' + destPath;
cb(null, destPath);
}
});
});
batch.push(function(cb) {
form.on('part', function(part) {
if (! part.filename) return;
cb(null, part);
});
});
batch.end(function(err, results) {
if (err) throw err;
form.removeListener('close', onEnd);
var destPath = '/' + userId + results[0];
var part = results[1];
var counter = new ByteCounter();
part.pipe(counter); // need this until knox upgrades to streams2
headers['Content-Length'] = part.byteCount;
s3Client.putStream(part, destPath, headers, function(err, s3Response) {
if (err) throw err;
res.statusCode = s3Response.statusCode;
s3Response.pipe(res);
console.log('https://s3.amazonaws.com/' + process.env.S3_BUCKET_IMAGES + destPath);
});
part.on('end', function() {
console.log('part end');
console.log('size', counter.bytes);
});
});
form.on('close', function(error) {
logger.error(error);
return ErrorController.sendErrorJson(res, 500, 'There was a problem uploading the file.');
});
form.parse(req);
});
};
看起来爆炸的部分是multiparty我对该代码进行了一些研究，但无济于事。我不确定我是否错误地发出了请求，或者我的服务器代码是否有问题。我不认为这与我的 S3 存储桶有任何关系，但我想也可能是这样。
无论如何，欢迎任何提示。
