Codigo Login

import { Component } from '@angular/core';
import { IonicPage, NavController, NavParams, LoadingController } from 'ionic-angular';
import { Http, Headers } from '@angular/http';
import { User } from '../../models/user';
import { Storage } from '@ionic/storage';
import { MainPage } from '../pages';

@IonicPage()
@Component({
  selector: 'page-login',
  templateUrl: 'login.html',
})
export class LoginPage {

  private message: string = '';

  public user = new User('', '', '', '', {});
  public userLoggedIn: User;

  constructor(public navCtrl: NavController,
              public navParams: NavParams,
              private _http: Http,
              private _loadingCtrl: LoadingController,
              readonly storage: Storage) {
  }

  Login() {
    if (!this.user.email && this.user.email.length === 0){
      this.message = 'Please fill the email field.';
    } else {

      if (!this.user.password && this.user.password.length === 0){
        this.message = 'Please fill the password field.';
      } else {

        var headers = new Headers();

        headers.append("Accept", 'application/json');
        headers.append('Content-Type', 'text/plain' );

        let json = JSON.stringify({ email: '' });

        let loader = this._loadingCtrl.create({
          content: 'Performing user verification, please wait ...'
        });

        loader.present();

        this._http.post('http://ec2-18-220-255-245.us-east-2.compute.amazonaws.com:8080/backend-ttac/login?email='+ this.user.email+ '&password='+ this.user.password, json, {headers: headers})
        .subscribe(data => {
          loader.dismiss();

          let result = data['_body'];

          if (result == -1){
            this.message = 'The email is invalid.';
          } else {
            if (result == -2){
              this.message = 'The password is invalid.';
            } else {
              if (result){
                this.message = '';
                this.userLoggedIn = JSON.parse( data['_body'] );
                this.storage.set('user', this.userLoggedIn);
                this.navCtrl.setRoot(MainPage);
              }
            }
          }
        }, (err) => {
          loader.dismiss();
          this.message = 'Error connecting to server, please try again later.';
        });
      }
    }
  }
}