Android How to Program, 3/e

7 WeatherViewer App

Objectives

In this chapter you’ll:

• Use the free OpenWeatherMap.org REST web services to get a 16-day weather forecast for a city specified by the user.

• Use an AsyncTask and an HttpUrlConnection to invoke a REST web service or to download an image in a separate thread and deliver results to the GUI thread.

• Process a JSON response using package org.json classes JSONObjects and JSONArrays.

• Define an ArrayAdapter that specifies the data to display in a ListView.

• Use the ViewHolder pattern to reuse views that scroll off the screen in a ListView, rather than creating new views.

• Use the material design components TextInputLayout, Snackbar and FloatingActionButton from the Android Design Support Library.

Outline

1. 7.1 Introduction ...