我是nodeJS的新手,我正在学习如何创建一个连接到mongoDB的简单api应用程序。
我阅读了一些博客并研究了一些简单的项目,我开始自己制作,但有一个小问题。我遵循了所有步骤,甚至自己检查了解决问题。
虽然,我没有成功,当我将它与api.js链接并且抛出以下错误时,问题出现在server.js中
D:\Node Js\nodeJs\userStory\node_modules\express\lib\router\index.js:458
throw new TypeError('Router.use() requires a middleware function but got a ' + gettype(fn))
^
TypeError: Router.use() requires a middleware function but got a undefined
at Function.use (D:\Node Js\nodeJs\userStory\node_modules\express\lib\router\index.js:458:13)
at Function.<anonymous> (D:\Node Js\nodeJs\userStory\node_modules\express\lib\application.js:220:21)
at Array.forEach (<anonymous>)
at Function.use (D:\Node Js\nodeJs\userStory\node_modules\express\lib\application.js:217:7)
at Object.<anonymous> (D:\Node Js\nodeJs\userStory\server.js:26:5)
at Module._compile (module.js:643:30)
at Object.Module._extensions..js (module.js:654:10)
at Module.load (module.js:556:32)
at tryModuleLoad (module.js:499:12)
at Function.Module._load (module.js:491:3)
at Function.Module.runMain (module.js:684:10)
at startup (bootstrap_node.js:187:16)
at bootstrap_node.js:608:3
如果有人可以查看它并指导我出错的地方会有所帮助。
//---Server.js
var express = require('express');
var bodyParser = require('body-parser');
var morgan = require('morgan');
var config = require('./config');
var mongoose = require('mongoose');
var app = express();
mongoose.connect(config.database,function(err){
if(err){
console.log(err);
}else{
console.log("Connected to a database");
}
});
app.use(bodyParser.urlencoded({extended:true}));
app.use(bodyParser.json());
app.use(morgan('dev'));
app.use("/api",require('./app/route/api')(app,express));
app.get('*',function(req,res){
res.sendFile(__dirname + '/public/views/index.html');
});
app.listen(config.port,function(err){
if(err){
console.log(err);
}else{
console.log("Listening on port "+config.port);
}
});
&#13;
//api.js
var user = require('../model/user');
var config = require('../../config');
var secretKey = config.secretKey;
module.exports = function(app,express){
var api = express.Router();
//passing the data to the DB
api.post('/signup',function(req,res){
var user = new User({
name:req.body.name,
username:req.body.username,
password:req.body.password
});//body here is the body parser for reading the value from the DB
//Now saving it on the DB
user.save(function(err){
if(err){
res.send(err);
return;
}
res.json({message:'User has been created'});
});
});
};
&#13;
答案 0 :(得分:2)
您应该导出路由器,而不是导出功能。
var api = express.Router();
//passing the data to the DB
api.post('/signup',function(req,res){
var user = new User({
name:req.body.name,
username:req.body.username,
password:req.body.password
});//body here is the body parser for reading the value from the DB
//Now saving it on the DB
user.save(function(err){
if(err){
res.send(err);
return;
}
res.json({message:'User has been created'});
});
});
module.exports = api;
相应地更改你的app.js
app.use("/api",require('./app/route/api'));
答案 1 :(得分:0)
在不同情况下会出现此错误。
对于我来说,当代码如下时,我会收到此错误
app.js
const { getRouter } = require('./routes/getAPIs');
...
expressServer.use("/", getRouter);
other.js
const router = expressServer.Router();
router.get("/", getData);
module.exports = router;
这里的问题是当不使用销毁方式(我们使用module.exports方法)时,使用销毁方式而不是常规方式。
解决方案是删除导入对象周围的{}。
app.js
const getRouter = require('./routes/getAPIs');
...
expressServer.use("/", getRouter);