Javascript express app eNote:没有此类文件或目录ajax调用500内部服务器错误

当ajax请求被激发时，我在控制台中得到以下错误消息：POST 500内部服务器错误

在节点cmd:enoint:no这样的文件或目录中，stat'pathtodir/speichen'

我在Javascript文件index.html中有此Ajax请求：

$.ajax({
        url:"http://localhost:3000/speichern",
        method:"POST",
        contentType:"application/json",
        data:JSON.stringify({highscore:score,name:name}),
        dataType:"JSON",
        success:function(responseData){
            console.log("Daten gespeichert");
        }

    })

这段代码在我的server.js中

 bp = require("body-parser");
express = require("express");
fs = require('fs');
serve = require("express-static");



app = express();
app.listen('3000',function(){

    console.log('server started on 3000');
});

app.use(bp.json());
app.use(serve(__dirname+'/'));


app.use(function(request,response,next){
    response.setHeader('Access-Control-Allow-Origin','*');
    response.setHeader('Access-Control-Allow-Methods','POST,OPTIONS');
    response.setHeader('Access-Control-Request-Headers','Content-Type');
    response.setHeader('Access-Control-Allow-Headers',"Origin, X-Requested- 
     With, Content-Type, Accept");
    next();
});



app.post('/speichern',function(request,response){
console.log('post speichern called');

    var thejson = {
    something:'test'
    }
    response.end(JSON.stringify(thejson));
});

在配置路由之前，您将开始侦听服务器

移动这些行：

app.use(serve(__dirname+'/'));
app.listen('3000',function(){
    console.log('server started on 3000');
});

直到代码的末尾