我正在使用Node.js Express框架上传文件，使用async.js处理该文件，并通过对/ design的POST请求将该文件呈现在页面上。然后，用户可以操作该图像，并可以按照对/ cart的POST请求转到其购物车。通过/ design上传和处理文件的过程完全符合我的要求，但是一旦用户继续浏览/ cart，此请求将保持待处理状态，而不会产生任何结果。
详细信息：
用户通过POST请求将文件上传到/ design，然后进行处理：
router.post('/design', function(req, res) {
var file;
req.session.uuid = sessionHandler.createUuid();
file = req.files.photo;
tasks = [
function fileUpload(cb){
fileHandler.upload(req.session,file,method,function(fileProperties){
for(var k in fileProperties) req.session[k]=fileProperties[k];
cb();
});
},
function setCookies(cb){
var imgData = {
S3FilePath: req.session.S3FilePath,
fullFilePath: req.session.fullFilePath,
uuid: req.session.uuid,
S3PreviewPath: req.session.S3PreviewFilePath
};
res.cookie('imgData', JSON.stringify(imgData), { maxAge: 900000, httpOnly: false, encode: String});
cb();
}
];
async.series(tasks, (err, results) => {
if (err){
console.log('Error:' + err);
} else{
console.log('Rendering image');
res.render('app',{ title : 'Designer' });
res.end();
}
});
});
/ design POST请求使用以下模块上传和处理文件。
var upload = function(session,file,callback){
var fileProperties = {};
tasks = [
function createDir(cb){
mkdirp('./public/uploads/'+session.uuid+'/', function(err) {
if (!err) {
console.log('directory created');
return cb();
} else{
cb(err);
}
});
},
function getFileExtension(cb){
request.post({
url:'http://localhost:1652/framer/getextension',
form: {
filePath: file.path
}
}, function(err,httpResponse,body){
if (err) console.log(err);
fileProperties.extension = body;
return cb();
});
},
function uploadLocal(cb){
fileProperties.fileName = session.uuid + '.' + fileProperties.extension;
fileProperties.previewPath = '/uploads/' + session.uuid + '/' + session.uuid + '-preview.' + fileProperties.extension;
fileProperties.fullFilePath = path.join(__dirname, '/../public/uploads/' + session.uuid + '/' + fileProperties.fileName);
fs.rename(file.path, fileProperties.fullFilePath, function(err){
if (err) throw cb(err);
console.log('file uploaded locally');
cb();
});
},
function uploadS3(cb){
request.post({
url:'http://localhost:1656/s3/put',
form: {
filePath: fileProperties.fullFilePath,
fileName: fileProperties.fileName
}
}, function(err,httpResponse,body){
if (err) throw cb(err);
console.log('file uploaded to S3');
fileProperties.S3FilePath = 'https://s3-ap-southeast-2.amazonaws.com/bucket/designer/'+fileProperties.fileName;
return cb();
});
},
function generatePreview(cb){
console.log("Calling preview method");
request.post({
url:'http://localhost:1652/framer/preview',
form: {
filePath: fileProperties.fullFilePath,
extension: fileProperties.extension,
dirName: __dirname,
uuid: session.uuid
}
}, function(err,httpResponse,body){
if (err) throw cb(err);
fileProperties.previewFullFilePath = body;
return cb();
});
},
function uploadPreviewS3(cb){
request.post({
url:'http://localhost:1656/s3/put',
form: {
filePath: fileProperties.previewFullFilePath,
fileName: session.uuid + '-preview.' + fileProperties.extension
}
}, function(err,httpResponse,body){
if (err) throw cb(err);
console.log('Preview file uploaded to S3');
fileProperties.S3PreviewFilePath = 'https://s3-ap-southeast-2.amazonaws.com/bucket/designer/'+session.uuid + '-preview.' + fileProperties.extension;
return cb();
});
}
];
async.series(tasks, (err, results) => {
if (err) {
console.log('File upload error:' + err);
} else{
callback(fileProperties);
}
});
};
当想要继续下一页时，发帖请求会将用户带到他们的购物车，我现在将其简化为仅显示console.log消息。
router.post('/cart', function (req, res){
console.log('Go to payment');
res.end();
});
此请求开始后，Chrome开发者工具中的请求将继续保持“待处理”模式，此后再无任何反应。一段时间后，终端中将显示以下内容：
POST /cart - - ms - -
在上传过程中显示的其他错误是ERR_HTTP_HEADERS_SENT错误和MaxListenersExceededWarning错误。不幸的是，除非我没有以正确的方式使用async.js，否则我无法在代码中的任何地方找到发送标头的原因。其次，我不确定为什么会出现MaxListenersExceededWarning错误，因为它是单个POST请求。
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at validateHeader (_http_outgoing.js:503:11)
at ServerResponse.setHeader (_http_outgoing.js:510:3)
at ServerResponse.header (/Users/dazzatron/designer/app/frontpage/node_modules/express/lib/response.js:767:10)
at ServerResponse.send (/Users/dazzatron/designer/app/frontpage/node_modules/express/lib/response.js:170:12)
at ServerResponse.send (/Users/dazzatron/designer/app/frontpage/node_modules/express-debug/lib/response.js:124:29)
at finalize (/Users/dazzatron/designer/app/frontpage/node_modules/express-debug/lib/response.js:47:21)
at toolbar_callback (/Users/dazzatron/designer/app/frontpage/node_modules/express-debug/lib/response.js:99:17)
at Object.exports.renderFile (/Users/dazzatron/designer/app/frontpage/node_modules/pug/lib/index.js:412:12)
at View.exports.__express [as engine] (/Users/dazzatron/designer/app/frontpage/node_modules/pug/lib/index.js:455:11)
at View.render (/Users/dazzatron/designer/app/frontpage/node_modules/express/lib/view.js:135:8)
directory created
Error [ERR_HTTP_HEADERS_SENT]: Cannot set headers after they are sent to the client
at validateHeader (_http_outgoing.js:503:11)
at ServerResponse.setHeader (_http_outgoing.js:510:3)
at ServerResponse.header (/Users/dazzatron/designer/app/frontpage/node_modules/express/lib/response.js:767:10)
at ServerResponse.send (/Users/dazzatron/designer/app/frontpage/node_modules/express/lib/response.js:170:12)
at ServerResponse.send (/Users/dazzatron/designer/app/frontpage/node_modules/express-debug/lib/response.js:124:29)
at finalize (/Users/dazzatron/designer/app/frontpage/node_modules/express-debug/lib/response.js:47:21)
at toolbar_callback (/Users/dazzatron/designer/app/frontpage/node_modules/express-debug/lib/response.js:99:17)
at Object.exports.renderFile (/Users/dazzatron/designer/app/frontpage/node_modules/pug/lib/index.js:412:12)
at View.exports.__express [as engine] (/Users/dazzatron/designer/app/frontpage/node_modules/pug/lib/index.js:455:11)
at View.render (/Users/dazzatron/designer/app/frontpage/node_modules/express/lib/view.js:135:8)
file uploaded locally
file uploaded to S3
Calling preview method
Preview file uploaded to S3
Rendering image
POST /design 200 4516.438 ms - 480447
(node:95893) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 field listeners added. Use emitter.setMaxListeners() to increase limit
(node:95893) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 file listeners added. Use emitter.setMaxListeners() to increase limit
(node:95893) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 error listeners added. Use emitter.setMaxListeners() to increase limit
(node:95893) MaxListenersExceededWarning: Possible EventEmitter memory leak detected. 11 end listeners added. Use emitter.setMaxListeners() to increase limit
POST /cart - - ms - -
任何有关我的POST请求为何一直卡住的帮助将不胜感激。