typeerror：app.use（）需要中间件功能 [英] typeerror: app.use() requires middleware function

问题描述

我正在用快速模板引擎学习node.js，我在跟随udemy课程通过构建10个项目学习node.js，同时在教授运行 npm start localhost：3000 开始，而我的弹出错误指示 app.use需要中间件功能
我尝试了匹配的代码和它相同。请帮我解决我已经被困在这里的错误几个小时尝试了大量的编辑，但它不适用于我。

当我试图运行'npm start'以下错误弹出

TypeError：app.use（）需要中间件函数

以下是app.js代码：

 code> var express = require（'express'）; 
 var path = require（'path'）; 
 var favicon = require（'serve-favicon'）; 
 var logger = require（'morgan'）; 
 var expressValidator = require（'express-validator'）; 
 var cookieParser = require（'cookie-parser'）; 
 var session = require（'express-session'）; 
 var passport = require（'passport'）; 
 var LocalStrategy = require（'passport-local'）。 
 var bodyParser = require（'body-parser'）; 
 var multer = require（'multer'）; 
 var flash = require（'connect-flash'）; 
 var mongo = require（'mongodb'）; 
 var mongoose = require（'mongoose'）; 
 var db = mongoose.connection; 
 
 var routes = require（'./ routes / index'）; 
 var users = require（'./ routes / users'）; 
 
 var app = express（）; 
 
 //查看引擎设置
 app.set（'views'，path.join（__ dirname，'views'））; 
 app.set（'view engine'，'jade'）; 
 
 //手柄文件上传
 app.use（multer（{
 dest：'./uploads'
}））; 
 
 //将您的图标放在/ public 
 //app.use(favicon(__dirname +'/public/favicon.ico'）中）后取消注释）; 
 app.use（logger（'dev'））; 
 app.use（bodyParser.json（））; 
 app.use（bodyParser.urlencoded（{
 extended：false 
}））; 
 
 // Handle Express Sessions 
 app.use（session（{
 secret：'secret'，
 saveUninitialied：true，
 resave：true 
}））; 
 
 //护照
 app.use（passport.initialize（））; 
 app.use（passport.session（））; 
 
 //验证器
 app.use（expressValidator（{
 errorFormatter：function（param，msg，value））{
 var namespace = param.split（' '），
 root = namespace.shift（），
 formParam = root; 
 
 while（namespace.length）{
 formParam + ='['+ namespace .shift（）+']'; 
} 
 return {
 param：formParam，
 msg：msg，
 value：value 
}; 
} 
}））; 
 
 app.use（cookieParser（））; 
 app.use（express.static（path.join（__ dirname，'public'）））; 
 
 app.use（flash（））; 
 
 app.use（function（req，res，next）{
 res.locals.messages = require（'express-messages'）（req，res）; 
 next （）; 
}）; 
 
 app.use（'/'，routes）; 
 app.use（'/ users'，users）; 
 
 // catch 404并转发到错误处理程序
 app.use（function（req，res，next）{
 var err = new Error（'Not Found'）; 
 err.status = 404; 
 next（err）; 
}）; 
 
 //错误处理程序
 
 //开发错误处理程序
 //将打印stacktrace 
 if（app.get（'env'）== ='development'）{
 app.use（function（err，req，res，next）{
 res.status（err.status || 500）; 
 res.render（'错误'，{
 message：err.message，
 error：err 
}）; 
}）; 
} 
 
 //生产错误处理程序
 //没有堆栈跟踪泄漏给用户
 app.use（function（err，req，res，next）{
 res.status（err.status || 500）; 
 res.render（'error'，{
 message：err.message，
 error：{} 
} ）; 
}）; 
 
 
 
 module.exports = app; 
  

这是package.json文件

  {
name：nodeauth，
version：1.0.0，
private ：
scripts：{
start：node ./bin/www
}，
dependencies：{
body-解析器：〜1.12.4，
cookie-parser：〜1.3.5，
debug：〜2.2.0，
express 〜4.12.4，
玉：〜1.9.2，
摩根：〜1.5.3，
serve-favicon：〜2.2 .1，
mongodb：*，
mongoose：*，
connect-flash：*，
express-validator ：*，
express-session：*，
express-messages：*，
护照：*，
 护照本地：*，
护照-http：*，
multer：*
} 
} 
  

这里是更新的app.js（删除multar之后）

  var express = require（'express'），
 path = require路径'），
 favicon = require（'serve-favicon'），
 logger = require（'morgan'），
 cookieParser = require（'cookie-parser'），
 expressValidator = require（'express-validator'），
 session = require（'express-session'），
护照= require（'护照'），
 LocalStrategy = - 'b 
 $ b bodyParser = require（'body-parser'），
 flash = require（'connect-flash'），
 mongo = require（'mongodb'）， 
 mongoose = require（'mongoose'），
 
 db = mongoose.connection，
 
 routes = require（'./ routes / index'），
 users = require（'./ routes / users'），
 
 app = express（）; 
 
 //查看引擎设置
 app.set（'views'，path.join（__ dirname，'views'））; 
 app.set（'view engine'，'jade'）; 
 
 //处理文件上传
 
 // multer delted 
 
 
 //将您的图标放在/ public $ b $后取消注释b //app.use(favicon(__dirname +'/public/favicon.ico'））; 
 app.use（logger（'dev'））; 
 app.use（bodyParser.json（））; 
 app.use（bodyParser.urlencoded（{extended：false}））; 
 
 // handle express sessions 
 app.use（session（{
 secret：'keyboard cat'，
 resave：true，
 saveUninitialized：true 
}））; 
 
 //护照
 app.use（passport.initialize（））; 
 app.use（passport.session（））; 
 
 //验证器
 app.use（expressValidator（{
 errorFormatter：function（param，msg，value））{
 var namespace = param.split（' '），
 root = namespace.shift（），
 formParam = root; 
 
 while（namespace.length）{
 formParam + ='['+ namespace .shift（）+']'; 
} 
 
 return {
 param：formParam，
 msg：msg，
 value：value 
}; 
} 
}））; 
 
 app.use（cookieParser（））; 
 app.use（express.static（path.join（__ dirname，'public'）））; 
 
 // flash 
 app.use（flash（））; 
 
 // express message 
 app.use（function（req，res，next）{
 res.locals.messages = require（'express-messages'）（req， res）; 
 next（）; 
}）; 
 
 app.get（'*'，function（req，res，next）{
 res.locals.user = req.user || null; 
 next（）; 
}）; 
 
 app.use（'/'，routes）; 
 app.use（'/ users'，users）; 
 
 // catch 404并转发到错误处理程序
 app.use（function（req，res，next）{
 var err = new Error（'Not Found'）; 
 err.status = 404; 
 next（err）; 
}）; 
 
 //错误处理程序
 
 //开发错误处理程序
 //将打印stacktrace 
 if（app.get（'env'）== ='development'）{
 app.use（function（err，req，res，next）{
 res.status（err.status || 500）; 
 res.render（'错误'，{
 message：err.message，
 error：err 
}）; 
}）; 
} 
 
 //生产错误处理程序
 //没有堆栈跟踪泄漏给用户
 app.use（function（err，req，res，next）{
 res.status（err.status || 500）; 
 res.render（'error'，{
 message：err.message，
 error：{} 
} ）; 
}）; 
 
 
 // Express服务器
 var http = require（'http'）; 
 var server = http.createServer（app）; 
 
 app.get（'/'，function（req，res）{
 res.send（Hello World！）; 
}）; 
 
 server.listen（3000，'localhost'）; 
 server.on（'listen'，function（）{
 console.log（'Express server started on port％s at％s'，server.address（）。port，server.address（） .address）; 
}）; 
 
 module.exports = app; 
  

谢谢

解决方案

它以这种方式工作。删除这一行，

  app.use （multer（{dest：'./uploads'}））; 
  

并将其用作

  var multer = require（'multer'）; 
 var upload = multer（{dest：'./uploads'}）; 
  

我也遵循相同的课程

I am learning node.js with express template engine, I am following udemy course "learn node.js by building 10 projects", while following a lecture when professor run npm start localhost:3000 starts while mine pops up error indicating app.use requires middleware function I have tried matching code and its same. Please help me to resolve the error i have been stuck here for hours tried a lot of edits but its not working for me.

When I am trying to run 'npm start' following error pops up

TypeError: app.use() requires middleware functions

Here is app.js code:

var express = require('express');
var path = require('path');
var favicon = require('serve-favicon');
var logger = require('morgan');
var expressValidator = require('express-validator');
var cookieParser = require('cookie-parser');
var session = require('express-session');
var passport = require('passport');
var LocalStrategy = require('passport-local').Strategy;
var bodyParser = require('body-parser');
var multer = require('multer');
var flash = require('connect-flash');
var mongo = require('mongodb');
var mongoose = require('mongoose');
var db = mongoose.connection;

var routes = require('./routes/index');
var users = require('./routes/users');

var app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

//Handle File Uploads
app.use(multer({
  dest: './uploads'
}));

// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({
  extended: false
}));

//Handle Express Sessions
app.use(session({
  secret: 'secret',
  saveUninitialied: true,
  resave: true
}));

//Passport
app.use(passport.initialize());
app.use(passport.session());

//Validator
app.use(expressValidator({
  errorFormatter: function(param, msg, value) {
    var namespace = param.split('.'),
      root = namespace.shift(),
      formParam = root;

    while (namespace.length) {
      formParam += '[' + namespace.shift() + ']';
    }
    return {
      param: formParam,
      msg: msg,
      value: value
    };
  }
}));

app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

app.use(flash());

app.use(function(req, res, next) {
  res.locals.messages = require('express-messages')(req, res);
  next();
});

app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});



module.exports = app;

Here is package.json file

{
  "name": "nodeauth",
  "version": "1.0.0",
  "private": true,
  "scripts": {
    "start": "node ./bin/www"
  },
  "dependencies": {
    "body-parser": "~1.12.4",
    "cookie-parser": "~1.3.5",
    "debug": "~2.2.0",
    "express": "~4.12.4",
    "jade": "~1.9.2",
    "morgan": "~1.5.3",
    "serve-favicon": "~2.2.1",
    "mongodb": "*",
    "mongoose": "*",
    "connect-flash": "*",
    "express-validator": "*",
    "express-session": "*",
    "express-messages": "*",
    "passport": "*",
    "passport-local": "*",
    "passport-http": "*",
    "multer": "*"
  }
}

Here is updated app.js (after removing multar)

var express          = require('express'),
    path             = require('path'),
    favicon          = require('serve-favicon'),
    logger           = require('morgan'),
    cookieParser     = require('cookie-parser'),
    expressValidator = require('express-validator'),
    session          = require('express-session'),
    passport         = require('passport'),
    LocalStrategy    = require('passport-local').Strategy,
    bodyParser       = require('body-parser'),
    flash            = require('connect-flash'),
    mongo            = require('mongodb'),
    mongoose         = require('mongoose'),

    db = mongoose.connection,

    routes = require('./routes/index'),
    users  = require('./routes/users'),

    app = express();

// view engine setup
app.set('views', path.join(__dirname, 'views'));
app.set('view engine', 'jade');

// handle file uploads

//multer delted


// uncomment after placing your favicon in /public
//app.use(favicon(__dirname + '/public/favicon.ico'));
app.use(logger('dev'));
app.use(bodyParser.json());
app.use(bodyParser.urlencoded({ extended: false }));

// handle express sessions
app.use(session({
  secret: 'keyboard cat',
  resave: true,
  saveUninitialized: true
}));

// passport
app.use(passport.initialize());
app.use(passport.session());

// validator
app.use(expressValidator({
  errorFormatter: function(param, msg, value) {
    var namespace = param.split('.'),
        root      = namespace.shift(),
        formParam = root;

    while(namespace.length) {
      formParam += '[' + namespace.shift() + ']';
    }

    return {
      param: formParam,
      msg  : msg,
      value: value
    };
  }
}));

app.use(cookieParser());
app.use(express.static(path.join(__dirname, 'public')));

// flash
app.use(flash());

// express messages
app.use(function(req, res, next) {
  res.locals.messages = require('express-messages')(req, res);
  next();
});

app.get('*', function(req, res, next) {
  res.locals.user = req.user || null;
  next();
});

app.use('/', routes);
app.use('/users', users);

// catch 404 and forward to error handler
app.use(function(req, res, next) {
  var err = new Error('Not Found');
  err.status = 404;
  next(err);
});

// error handlers

// development error handler
// will print stacktrace
if (app.get('env') === 'development') {
  app.use(function(err, req, res, next) {
    res.status(err.status || 500);
    res.render('error', {
      message: err.message,
      error: err
    });
  });
}

// production error handler
// no stacktraces leaked to user
app.use(function(err, req, res, next) {
  res.status(err.status || 500);
  res.render('error', {
    message: err.message,
    error: {}
  });
});


//Express server
var http = require('http');
var server = http.createServer(app);

app.get('/', function(req, res) {
    res.send("Hello World!");
});

server.listen(3000, 'localhost');
server.on('listening', function() {
    console.log('Express server started on port %s at %s', server.address().port, server.address().address);
});

module.exports = app;

Thank You

解决方案

It worked in this way. delete this line,

app.use(multer({ dest: './uploads' }));

and use it as,

var multer = require('multer');
var upload = multer({ dest: './uploads' });

I'm too following the same course

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