downloadfile(filePath: string){
        return this.http
            .get( URL_API_REST + 'downloadMaj?filePath='+ filePath)
            .map(res => new Blob([res], {type: 'application/zip'}))
    }

downloadfileComponent(filePath: string){
        this.appService.downloadfile(filePath)
            .subscribe(data => this.getZipFile(data)),
                error => console.log("Error downloading the file."),
                () => console.log('Completed file download.');
    }


getZipFile(data: any){
        var a: any = document.createElement("a");
        document.body.appendChild(a);

        a.style = "display: none";
        var blob = new Blob([data], { type: 'application/zip' });

        var url= window.URL.createObjectURL(blob);

        a.href = url;
        a.download = "test.zip";
        a.click();
        window.URL.revokeObjectURL(url);

    }

public void downloadMaj(@RequestParam(value = "filePath") String filePath, HttpServletResponse response) {

        System.out.println("downloadMaj");
        File fichierZip = new File(filePath);

        try {
            System.out.println("nom du fichier:" + fichierZip.getName());
            InputStream inputStream = new FileInputStream(fichierZip);

            response.addHeader("Content-Disposition", "attachment; filename="+fichierZip.getName());
            response.setHeader("Content-Type", "application/octet-stream");

            org.apache.commons.io.IOUtils.copy(inputStream, response.getOutputStream());
            response.getOutputStream().flush();
        } catch (FileNotFoundException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
    }

const options:any = {
    headers: new HttpHeaders({'Content-Type': 'file type of an particular document'}),
    withCredentials: true,
    responseType:'arraybuffer'
  };

    return this.http.get<Content>(url,options);

  }