File Upload with Angular2 to REST API

Actually, I'm working on a Spring REST API with an interface coded in Angular 2.

My problem is I can't upload a file with Angular 2.

My Webresources in java is that :

@RequestMapping(method = RequestMethod.POST, value = "/upload")
public String handleFileUpload(@RequestParam MultipartFile file) {
    //Dosomething 
}

And it is perfectly working when I call it through URL request with Auth header etc ... ( with Advanced Rest Client extension for Chrome )

Proof: (everything works fine in that case )

I added the

<bean id="multipartResolver"
      class="org.springframework.web.multipart.commons.CommonsMultipartResolver" />

Spring config file and the Pom dependency

<dependency>
    <groupId>commons-fileupload</groupId>
    <artifactId>commons-fileupload</artifactId>
    <version>1.2</version>
</dependency>

BUT when I try to do the same thing with a webform :

<input type="file" #files (change)="change(files)"/>
<pre>{{fileContents$|async}}</pre>

With the (change) method :

change(file) {
    let formData = new FormData();
    formData.append("file", file);
    console.log(formData);
    let headers = new Headers({
        'Authorization': 'Bearer ' + this.token,
        'Content-Type': 'multipart/form-data'
    });
    this.http.post(this.url, formData, {headers}).map(res => res.json()).subscribe((data) => console.log(data));
    /*
    Observable.fromPromise(fetch(this.url,
        {method: 'post', body: formData},
        {headers: this.headers}
    )).subscribe(()=>console.log('done'));
    */
}

My web service returns me an error 500, with that in tomcat logs: http://pastebin.com/PGdcFUQb

I tried the 'Content-Type': undefined method too but without success ( the web service return me a 415 error in that case.

Can someone help me to figure out what's the problem is?

Problem solved, I'll update that question later with my code :) but, have a look on the plunker it's working perfectly well. Thanks.