多个asynchronous请求

那么，这里im triyng在对象列表中进行一些validation，但函数validation调用三个asynchronous方法（它向数据库发出请求）。但是当我以平行方式调用时，应用程序会给出错误500。

_.each(titlesToSave, function(title, index) { titleValidator.validateAsync(title, function (err) { if (err) { invalidTitles.push({index: index, error: err}); } joinArray[index](); }); }); var validateAsync = function (title, next) { async.parallel([ function(callback){ checkCity(title.carrier.address, callback)}, function(callback){ checkCity(title.beneficiary.address, callback)}, function(callback){ checkCity(title.seller.address, callback)} ], function (err,results) { if(err){ console.log('ERROR: ' +err); next(err); }else{ console.log('Result: '+results); next(); } }); }; var checkCity = function(adress, callback){ var url = 'http://localhost:9000/api/city/'+adress.state+'/'+adress.city; if (adress) { http.get(url, function (res) { console.log('STATUS: ' + res.statusCode); res.on('data', function (chunk) { if (res.statusCode === 200) { console.log(''+chunk); callback(null, chunk); } else { console.log('Invalid city: '+adress.city+', StatusCode: ' + res.statusCode); callback(new Error('Invalid adress.')); } }); }).on('error', function (error) { callback(error); }); } }; 

Answer 1

尝试这个，

 async.eachSeries(titlesToSave, function (title, index, next) { titleValidator.validateAsync(title, function (err) { if (err) { invalidTitles.push({index: index, error: err}); } joinArray[index](); next(null); }); }, function (err) { console.log(err); });