（Angular4 / MEAN）将请求发送到空本体的本地API结果

我试图发布数据到一个项目的API，例如：

"data": { "title": "stack", "notes": "asdsad", "time": "19:02", "meridian": "PM", "type": "Education", "_id": "5a2f02d3bba3640337bc92c9", "days": { "Monday": true, "Tuesday": false, "Wednesday": false, "Thursday": false, "Friday": false, "Saturday": false, "Sunday": false } } 

但是，使用HttpClient发布数据时

  this.http.post("http://localhost:3000/api/items", JSON.stringify(item)) .subscribe( (val) => { console.log("POST call successful value returned in body", val); }, response => { console.log("POST call in error", response); }, () => { console.log("The POST observable is now completed."); }); 

我总是从API中的Items Controller得到Bad Request 400响应。

 exports.createItem = async function(req, res, next){ // Req.Body contains the form submit values. console.log(req); console.log(req.body); var item = { id: req.body.id, title: req.body.title, days: req.body.days, notes: req.body.notes, time: req.body.time, meridian: req.body.meridian, type: req.body.type, completed: req.body.completed, } try{ // Calling the Service function with the new object from the Request Body var createdItem = await ItemService.createItem(item) return res.status(201).json({status: 201, data: createdItem, message: "Succesfully Created Item"}) } catch(e){ console.log(e); //Return an Error Response Message with Code and the Error Message. return res.status(400).json({status: 400, message: "Item Creation was Unsuccesfull"}) } } 

我已经在我的app.js中设置了BodyParser

 app.use(bodyParser.json()); app.use(bodyParser.urlencoded({ extended: false })); 

在快速控制台中，输出如下

  _startTime: 2017-12-11T22:35:18.204Z, _remoteAddress: '::1', body: {}, secret: undefined, cookies: {}, signedCookies: {}, route: Route { path: '/', stack: [ [Object], [Object] ], methods: { post: true } } } {} 

正如你所看到的，身体是空的，这是防止一个项目被创build。 我已经使用Postman进行了testing，发送url编码的表单数据和原始的JSON数据的post成功并返回200.但是，我永远不能得到应用程序的请求工作。

任何帮助表示赞赏，因为我一直在为此奋斗了几个小时。

Answer 1

  this.http.post("http://localhost:3000/api/items", JSON.stringify(item) -----> convert JSON object to string ).subscribe(...); 

基于你的服务器端代码，我相信它期望JSON对象而不是JSONstring，因此从你的客户端删除JSON.stringify(item)) ，你的POST的主体应该是JSON对象。