如何解决MEAN应用程序中的GET 404（未找到）错误？

Question

我目前正试图获得用户的详细信息（的登录用户），我建立一个个人资料页面上，但我收到此错误：

GET http://localhost:3000/users/undefined 404 (Not Found) 
error_handler.js:54 EXCEPTION: Response with status: 404 Not Found for 
URL: http://localhost:3000/users/undefined 

我认为这可能是一个问题与字符串化的JSON数据，但这似乎没有改变任何东西，我读过Angular 2不再需要它。

我使用localhost：4200作为Angular，localhost：3000作为Express。当我对localhost：3000/users/id（使用对象ID）执行api调用时，它会返回json数据。我不确定什么是错的。

快递航线

router.get('/id', (req, res) => { 
    console.log("getting a specific user"); 
    if(!mongoose.Types.ObjectId.isValid(req.params.id)) { 
     return res.status(400).json({ message: 'Specified id is not valid' }); 
    } 

    User.findById(req.params.id, (err, users) => { 
     if (err) { 
      return res.send(err); 
     } 

     return res.json(users); 
     }); 


    }); 

角服务

import { Injectable } from '@angular/core'; 
import { AuthService } from './auth.service'; 
import { Http, Headers, RequestOptions, Response } from '@angular/http'; 

@Injectable() 
export class UserService { 

    BASE_URL: string = 'http://localhost:3000'; 

    constructor(
    private http: Http, 
    private authService: AuthService 

) { } 

    get(id) { 
    let headers = new Headers({ 'Authorization': 'JWT ' + this.authService.token }); 
    let options = new RequestOptions({ headers: headers }); 
    return this.http.get(`${this.BASE_URL}/users/${id}`, options) 
    .map((res) => res.json()); 
} 

轮廓组件

import { Component, OnInit, Input } from '@angular/core'; 
import { AuthService } from '.././services/auth.service'; 
import { UserService } from '.././services/user.service' 
import { Router, ActivatedRoute } from '@angular/router'; 


@Component({ 
    selector: 'app-profile', 
    templateUrl: './profile.component.html', 
    styleUrls: ['./profile.component.css'], 
    providers: [UserService] 
}) 
export class ProfileComponent implements OnInit { 

    currentUser; 

    isAuth: boolean; 

    constructor(
    private session: AuthService, 
    private router: Router, 
    private userService: UserService, 
    private route: ActivatedRoute 

) { 


    this.session.isAuth 
     .subscribe((isAuth: boolean) => { 
     // user will be false if logged out 
     // or user object if logged in. 
     this.isAuth = isAuth; 
     }); 
    if (this.session.token) { 
    this.isAuth = true; 
    console.log(this.session); 
    } else { 
    this.isAuth = false; 
    } 

    } 




    ngOnInit() { 

    this.route.params.subscribe(params => { 
     this.getUserDetails(params['id']); 
    }); 


    } 

    getUserDetails(id) { 
    this.userService.get(id) 
     .subscribe((user) => { 
     this.currentUser = user; 
     console.log(this.currentUser); 
     }); 
    } 


    } 

Answer 1

，请使用以下代码：

快递航线

router.get('/users/:id', (req, res) => { 
console.log("getting a specific user"); 
if(!mongoose.Types.ObjectId.isValid(req.params.id)) { 
    return res.status(400).json({ message: 'Specified id is not valid' }); 
} 
else { 
User.findById(req.params.id, (err, users) => { 
if (err) { 
    return res.send(err); 
} 
else { 
    return res.json(users); 
} 
}); 
} 
}); 

角服务

import { Injectable } from '@angular/core'; 
import { AuthService } from './auth.service'; 
import { Http, Headers, RequestOptions, Response } from '@angular/http'; 

@Injectable() 
export class UserService { 

BASE_URL: string = 'http://localhost:3000'; 

constructor(
private http: Http, 
private authService: AuthService 

) { } 

get(id) { 
let headers = new Headers({ 'Authorization': 'JWT ' + this.authService.token }); 
let options = new RequestOptions({ headers: headers }); 
return this.http.get(this.BASE_URL + '/users/' + id, options) 
.map((res) => res.json()); 
} 

我希望，这部作品根据自己的需要。