How to cancel a HTTPRequest in Angular 2?

You can use the following simple solution:

if ( this.subscription ) {
   this.subscription.unsubscribe();
}
this.subscription = this.http.get( 'awesomeApi' )
 .subscribe((res)=> {
  // your awesome code..
})

You can call unsubscribe

let sub = this.http.get(url, {headers: reqHeaders})
            .subscribe(
                (res) => {
                    res = res.json();

                    this.currentLoading.delete(url);
                    this.cache.set(url, res);

                    resolve(res);
                }
            );

sub.unsubscribe();

More info here: http://www.syntaxsuccess.com/viewarticle/angular-2.0-and-http