import {saveAs} from 'file-saver';



   downloadFileService(url,opts){
        return this._http.get(url,opts,{
            responseType : 'blob',
            headers:new HttpHeaders().append('Content-Type','application/json')
        });
    }

    downloadFile(){
        downloadFileService('url','options').subscribe((resp)=>{
saveAs(resp,'filename.txt')
        },(err)=>{
            console.log('downloadFile erro',err);
        })
    }