Req.body One route can use other routes as undefined?

  node.js, question

It is strange that one route can be used normally, but the others cannot?
Back end:

app.post('/login',function(req,res){
 console.log(req.body);
 var name = req.body.name;
 var password = req.body.upwd;
 var sss = req.body.sss;
 Log ('sss' plus sss);
 
 var User = global.dbHelper.getModel('user');
 
 User.findOne({name:name},function(error,doc){
 Log ('name:' plus doc['name'] plus' ---password:' plus doc['password']);
 
 if(error){
 return res.status(500).send({error:error});
 bracket
 if(!  doc){
 Error =' user does not exist';
 res.send(404);
 }else if(doc['password']!  =password){
 
 Error = "password error";
 res.send(404);
 }else{
 req.session.user=doc;
 res.send(200);
 bracket
 });
 
 });
 
 app.post('/aaa',function(req,req){
 console.log(req);
 Console.log("aa: "add req.body.aa add" bb: "add req.body.bb);
 res.status(200);
 });

Front end:

function account(){
         $.ajax({
            url:'/aaa',
            type:'POST',
            data:'aa=yeuu234&bb=14',
            success:function(data,status){
                if(status == 'success'){ 
                    
                    console.log('ajax success');
                }
            },
            error:function(res,err){
                
                console.log('ajax failue');
            }
        });
     };

Browser:
图片描述

After browsing, I found that the function parameter of app.post inside is written as (req,req), sometimes it may be a small problem.