Request HTTP ionic 2 GET

Simple, inject the Http of angular and then make the requisition. After that, just do an alert using some ionic component.

Depending on the site you are requesting, you may have a problem with CORS ( related topic ).

Example:

import { Http, Response, URLSearchParams } from '@angular/http';
import { AlertController } from 'ionic-angular';

constructor(
        private http: Http, 
        private alertCtrl: AlertController) { }

requisicao() {
    let params: URLSearchParams = new URLSearchParams;
        params.set('parametro1', 'bla');
        params.set('parametro2', 'bla2');

    this.http.get('http://..., {
        search: params
    }).toPromise().then(response => {
        let alert = this.alertCtrl.create({
            title: 'Good Lock!',
            subTitle: response,
            buttons: ['OK']
        });

        alert.present();
    });
}

Note: Remembering that doing everything together (in the same class) can make your code more coupled and less cohesive. Try to properly separate class responsibilities.