title: Excel upload using Angular2(Frontend) and Springboot (Backend)
body: <p>Hi I am new to angular2 and I am trying to upload an excel from an angular2 
     frontend .What exactly I want to achieve is , upload the excel from angular2 
     frontend pass it to Springboot in backend ,inside springboot I will make 
     necessary changes .Finally pass it back to angular to render it on screen .</p>
  
  <pre><code>My Approach :
  let user select the excel from frontend 
  POST it to springboot backend , make necessary modification using apache POI 
  Finally pass it to angular again to render it on screen .
  
  
  Problem Area :-
  
  
  I have made the frontend part to recieve input 
  
  
  below is my code :-
  
       &lt;input type="file" id="myfile" class="form-control" [(ngModel)]="fileObj" (change)="upload($event)" accept=".xlsx"&gt;
  
  
  Angular Component method to called on change of element :-
  
      file: File
      upload(event : EventTarget){
  
      let eventObj : MSInputMethodContext = &lt;MSInputMethodContext&gt; event ;
      let target : HTMLInputElement = &lt;HTMLInputELement&gt;  eventObj.target ;
      let files : FileList = target.files ;
      this.file = files[0];
      this._appService.sendFile(this.file);
  
      }
  
  above functions calls the sendFile method in appservice of angular2
  
  below is the code for appService :-
  
  
      private headers = new Headers({'Content-Type' : 'multipart/form-data'});
  
      sendFile(fileObj : File){
      return this.http.post('http://localhost:9000/submitexcel', fileObj, {headers : this.headers}).map(res =&gt; res.json().data).subscribe();
  
      }
  </code></pre>
  
  <p>Springboot Controller to recieve the incoming file .</p>
  
  <pre><code>@RestController
  public class ExcelUploadController {
  
  @RequestMapping(method = RequestMethod.POST , value="/submitexcel")
  public ResponseEntity&lt;String&gt; getFile(@RequestParam("File") MultipartFile file){
  System.out.println("inside controller");
  }
  }
  </code></pre>
  
  <p>whenever I make a call to controller , I get error on console :-</p>
  
  <p>"the request was rejected because no multipart boundary was found "</p>
  
  <p>Now below are my problem questions :-</p>
  
  <ol>
  <li>Am I not sending the excel file properly to springboot ??If not please let me know the correct way to do it </li>
  </ol>
  
  <p>2.Is my approach correct to achieve what is required ?</p>
  
  <p>3.How will I send the excel back from springboot to angular to display on Frontend ??</p>
  
  <p>I tried googling a lot about this, but could not find anything useful </p>
  
  <p>Please help me ,I am stuck since many days , thanks </p>