Angular 2 SyntaxError:意外令牌<在JSON.parse(< anonymous>)位置0的JSON中

我正在从Visual Studio的Angular2组件服务中调用Web API，但是不断出现错误"JSON.parse()中位置0的JSON中的意外令牌<".

I am calling the web API from my Angular2 Component service in Visual Studio, but continuously I am getting the error "Unexpected token < in JSON at position 0 at JSON.parse ()".

ComponentService:

ComponentService:

       import { Injectable } from '@angular/core';
       import {Http, Response } from '@angular/http';
       import { IData } from '../Common/details';
       import { Observable } from 'rxjs/Observable';
       import 'rxjs/add/operator/map';

       @Injectable()  
       export class AniversaryService {
         constructor(private _http:Http) { }
         getImages(): Observable<IData[]> {
                return this._http.get("/api/ImageService/Details")
                .map((response: Response) => <IData[]>response.json()      
                };
        }

，对应的组件是:

    import { Component, OnInit } from '@angular/core';
    import { DomSanitizer } from '@angular/platform-browser';
    import { IData } from '../Common/details';
    import { AniversaryService } from './Aniversary.service';

    @Component({
    selector: 'my-AniversaryComponent',
    providers: [AniversaryService]
    })

    export class AniversaryComponent implements OnInit {
       data: IData[];
       constructor(private _aniversaryservice: AniversaryService) { }
       ngOnInit() {
       this._aniversaryservice.getImages().subscribe((details) => this.data 
       =details); 
       }
     }

    }

这些是网络标头和我的响应的图像(响应是Java语言):

These are the images of network Headers and my response (response is in Javascript):

有时我的状态码显示200 ok和内容类型(在响应标题中):application/javascript

Sometimes my status code showing 200 ok and content type (in Response Headers): application/javascript

请帮助我解决这个问题.

Please help me to solve this problem.

感谢您的提前帮助