想要在xauth中保存我唯一的令牌，但它保存了所有内容吗？

onlogin() {
 this.loginService.sendCredential(this.credential.username, 
 this.credential.password).subscribe(
    res => {
    localStorage.setItem("X-Auth-Token",res.json().token);
    this.loggedIn = true;
    location.reload();
    this.router.navigate(['/home']);
}, 
    error => {
        this.loggedIn = false;
        this.loginError = true;
    }
);
}

这是mylogincomponent.ts中的onlogin（）函数

import { Injectable } from '@angular/core';
import {Http, Headers} from '@angular/http';
import {Observable} from 'rxjs';
import {AppConst} from '../constants/app-const';
import {Router} from '@angular/router';

@Injectable()


export class LoginService {
private serverPath:string = AppConst.serverPath;

constructor(private http:Http, private router:Router) { }

sendCredential(username: string, password: string) {
let url = this.serverPath+'/token';
let encodedCredentials = btoa(username+":"+password);
let basicHeader = "Basic "+encodedCredentials;
let headers = new Headers({
    'Content-Type' : 'application/x-www-form-urlencoded',
    'Authorization' : basicHeader
});

return this.http.get(url, {headers: headers});
}

checkSession() {
let url = this.serverPath+'/checkSession';
let headers = new Headers({
    'x-auth-token' : localStorage.getItem('xAuthToken')
});

return this.http.get(url, {headers: headers});
}

通过运行它，它在控制台中显示此错误

core.js：12501 ERROR SyntaxError：在Response.push上的JSON.parse（）的JSON输入的意外结束../ node_modules/@angular/http/fesm5/http.js.Body.json(http.js:719）在SafeSubscriber.p上的SafeSubscriber.next（myaccount.component.ts：41），在SafeSubscriber.push .. / node_modules / rxjs / esm5 / internal / Subscriber.js.SafeSubscriber . tryOrUnsub（Subscriber.js：196），位于SafeSubscriber.push ../ node_modules Subscriber.push上的/rxjs/_esm5/internal/Subscriber.js.SafeSubscriber.next(Provcriber.js：134）../ node_modules / rxjs / _esm5 / internal / Subscriber.js.Subscriber._next（Subscriber.js：77）在Subscriber.push ../ node_modules / rxjs / _esm5 / internal / Subscriber.js.Subscriber.next（Subscriber.js：54），位于ZoneDelegate.push ../ node_modules / zone的XMLHttpRequest.onLoad（http.js：1070） Object.onInvokeTask中的.js / dist / zone.js.ZoneDelegate.invokeTask（zone.js：421）（core.js：14051）

我该如何解决这个错误？