Android Software Development: A Collection of Practical Projects

263 Pages·2016·6.32 MB·English

by  Mark Wickham

Android
Software
Development
Android
Software
Development

A Collection of
Practical Projects

Mark Wickham
Android Software Development
A collection of practical projects
by Mark Wickham

Copyright © 2017 by Mark Wickham
All rights reserved.

Editor: Mary Sue Wickham
Cover design: Mark Wickham

While every attempt has been taken in the preparation of this book, the
publisher and author assume no responsibility for errors or omissions,
or for damages resulting from the use of the information contained
herein nor the companion software provided.

ISBN: 9781530149025

Printing History:
First Print January 2017

Printed in the United States of America
To my parents
who helped me discover
computers and software
when I was young.
P
Preface
Overview
Androidd Software Development is a new book by Android instructor
Mark Wickham. Mark has been teaching a series of popular classes at
Android development conferences since 2013. This new book covers
content from his most popular classes. Each chapter covers an important
concept and provides the reader with a deep dive into the
implementation.
The book uses a project-based approach. Unlike most books on the
market today, Android Software Development provides complete working
code for all of the projects. Developers appreciate this approach because
it enables them to focus on their apps, and not waste time trying to
integrate code snippets or troubleshoot environment setup issues.
Android Software Development is an ideal resource for developers who
have some development experience, but may not be Android or mobile
development experts. Each chapter includes at least one complete
project to show the reader how to implement the concepts. In Android,
there are always multiple ways to accomplish a given task. Android
Software Development helps developers choose the best approach for their
app and lets developers implement their solution quickly by leveraging
complete projects.

Preface | 7
Audience
This book is intended for software developers who want to create apps
for the Android platform.
Because we are developing for Android, in addition to mastering the Java
programming language, we must also master the intricacies of the
platform itself.
s not easy to create commercial apps for the Android platform.
Developers can easily become frustrated for a variety reasons:
(cid:2) Project setup is not trivial in Android. Whether you are using the
latest version of Android Studio or an alternative development
environment such as Eclipse, it can sometimes be frustrating
making sure all of the libraries, manifest, and project assets are set
up correctly.
(cid:2) When developers identify the requirement for a specific
functionality in their Android App, it is often difficult to find
working code or to integrate the code snippets which are readily
available from various online resources.
(cid:2) The Android platform and Java programming language have many
functionality. There are often multiple approaches to implement a
particular desired feature. The book helps developers decide the
best approach for their apps.
(cid:2) We often need to make architecture decisions when writing
Android apps, especially when we require a server connection. It
takes experience to implement solutions which can meet
performanc
right architecture, developers can be faced with a code rewrite or
refactoring effort after the app is launched.
(cid:2) There are a lot of code fragments available online. However, it is
often not easy to integrate these assets into your own project. They
may be incomplete or frequently contain errors and are thus not
able to be compiled. The book contains 14 compete Android
projects. It is easy to get the projects up and running.

Preface | 8
Table of Contents

P Preface ............................................................................................. 7

Overview ............................................................................................ 7

Audience ............................................................................................. 8

Table of Contents ............................................................................... 9

Chapter Layout ................................................................................ 14

Project Summary .............................................................................. 15

Conventions ..................................................................................... 20

Companion Website ........................................................................ 21

Development Environment ............................................................. 22

Software License............................................................................... 22

Acknowledgements .......................................................................... 23

About the Author ............................................................................. 23

Colophon.......................................................................................... 24

1 Introduction to JSON .................................................................... 25

1.1 Introduction ............................................................................... 25

1.2 Chapter Projects ......................................................................... 26

1.3 JSON Overview ........................................................................... 26

1.4 JSON and Android ...................................................................... 28

1.5 Designing JSON .......................................................................... 28

JSON Sample File ...................................................................... 29

Validating JSON ....................................................................... 30

Text File Encoding .................................................................... 31

1.6 Common JSON Operations ........................................................ 32

Setting a JSON Value in a JSON Object .................................... 32

Getting a JSON Value from a JSON Object .............................. 33

Creating a JSON file Programmatically .................................... 34

Reading and Parsing a JSON file............................................... 35

Printing JSON Strings ............................................................... 35

Removing JSON Arrays ............................................................. 36

1.6 JSON Alternatives ....................................................................... 37

GSON ........................................................................................ 38

Jackson ..................................................................................... 39

1.7 References ................................................................................... 40

Android JSON ........................................................................... 40

Google GSON ........................................................................... 40

3rd Party ................................................................................... 40

2 Connectivity .................................................................................. 41

2.1 Introduction ............................................................................... 41

2.2 Chapter Projects ......................................................................... 42

2.3 Connectivity Basics .................................................................... 42

2.4 Android HTTP Options .............................................................. 44

2.5 Connectivity Status .................................................................... 47
Preface | 9
Using the Built in APIs ............................................................. 47

Wifi Broadcast Receiver ............................................................ 48

2.6 Server Reachability .................................................................... 49

Pinging with ICMP ................................................................... 49

Pinging with HTTP ................................................................... 51

2.7 Connections App ........................................................................ 55

Connections App Overview ..................................................... 55

Connections Project ................................................................. 56

2.8 Splash App .................................................................................. 63

Splash App Overview ............................................................... 63

Splash Project ........................................................................... 65

2.9 Essential Tools ............................................................................ 70

2.10 References ................................................................................. 72

Android HTTP and Connectivity ............................................. 72

ApacheHttpClient .................................................................... 72

OkHttp ...................................................................................... 72

Tools ......................................................................................... 72

3 Lazy Loading Images .................................................................... 73

3.1 Introduction ............................................................................... 73

3.2 Chapter Projects ......................................................................... 74

3.3 Lazy Loading Libraries ............................................................... 74

3.4 Lazy Loading Architecture ......................................................... 75

Memory Cache ......................................................................... 77

Disk Cache ................................................................................ 78

3.5 Choosing a Library ..................................................................... 79

Google Volley ........................................................................... 80

Square Picasso ........................................................................... 81

Facebook Fresco ........................................................................ 82

3.6 Handling Image Assets ............................................................... 83

Size Verse Quality Tradeoff ...................................................... 84

Image Down Sampling ............................................................. 85

Aspect Ratio .............................................................................. 86

3.7 Lazy Loading App ...................................................................... 87

Lazy Loading App Overview .................................................... 88

Lazy Loading Project ................................................................ 89

3.8 References ................................................................................. 110

Android & Java References ..................................................... 110

3rd Party Lazy Loading Libraries ............................................ 110

4 Remote Crash Logs ...................................................................... 113

4.1 Introduction ............................................................................. 113

4.2 Chapter Projects ....................................................................... 114

4.3 Remote Crash Log Solutions .................................................... 114

How Crash Logging Works .................................................... 116

4.4 App Crash Report for Android - ACRA .................................... 117

ACRA Overview ...................................................................... 118
Preface | 10
4.5 ACRA Back End Server ............................................................. 119

4.6 Open Street Map for Android .................................................. 121

4.7 Remote Crash Log App ............................................................ 124

Remote Crash Log App Overview .......................................... 124

Remote Crash Log Project ...................................................... 127

4.8 References ................................................................................. 133

Android .................................................................................. 133

Google Firebase ...................................................................... 133

OSMdroid ............................................................................... 133

3rd Party ................................................................................. 133

5 Uploading & Emailing ................................................................ 135

5.1 Introduction ............................................................................. 135

5.2 Chapter Projects ....................................................................... 136

5.3 Overview .................................................................................. 136

5.4 Server Spinner - Server Setup ................................................... 137

5.5 Server Spinner App................................................................... 140

Server Spinner App Overview ................................................. 140

Server Spinner Project ............................................................ 141

5.6 Mobile Email ............................................................................ 150

5.7 Mobile Email Approaches ........................................................ 151

5.8 Email Protocols ........................................................................ 152

5.9 Android Email Clients ............................................................. 153

5.10 Emailing App - Server Setup .................................................. 153

5.11 Emailing App ......................................................................... 154

Emailing App Overview ......................................................... 155

Emailing Project ..................................................................... 157

5.12 References ............................................................................... 165

Uploading ............................................................................... 165

Email ....................................................................................... 165

6 Push Messaging ........................................................................... 167

6.1 Introduction ............................................................................. 167

6.2 Chapter Projects ....................................................................... 168

6.3 Push Messaging Overview ........................................................ 168

Origins of Push Messaging ..................................................... 169

Push Technologies .................................................................. 170

How Push Messaging Works .................................................. 172

Choosing a Technology ......................................................... 173

Firebase Cloud Messaging ...................................................... 175

FCM Quickstart App ............................................................... 177

FCM App Server ...................................................................... 178

GCM/FCM Considerations ..................................................... 179

6.4 Push Messaging Services .......................................................... 179

Advantages ............................................................................. 180

Choosing a Push Service ........................................................ 180

Setup Steps .............................................................................. 181
Preface | 11
6.5 Google Cloud Messaging .......................................................... 182

GCM Setup ............................................................................. 182

GCM App................................................................................ 183

GCM Project ........................................................................... 184

GCM Server Setup .................................................................. 188

GCM Upstream Messaging ..................................................... 191

GCM Topic Messaging ........................................................... 192

GCM/FCM Wrap up ............................................................ 193

6.6 Open Source Push Messaging with MQTT............................... 194

MQTT Introduction ................................................................ 194

MQTT App .............................................................................. 196

MQTT Project ......................................................................... 197

MQTT Server Setup Message Broker .................................... 202

Sending Messages MQTT Web Clients ................................ 202

6.7 References ................................................................................. 205

Push Services .......................................................................... 205

Google Cloud Messaging (GCM) ........................................... 205

Firebase Cloud Messaging (FCM) ........................................... 205

MQTT Push Messaging ........................................................... 206

7 Android Audio............................................................................. 207

7.1 Introduction ............................................................................. 207

7.2 Chapter Projects ....................................................................... 210

7.3 Audio Overview ........................................................................ 211

API and Class Summary ......................................................... 211

Choosing the Right API .......................................................... 213

7.4 Latency ..................................................................................... 214

Latency Breakdown ................................................................ 216

Audio Buffer Size App ............................................................. 218

Audio Buffer Size Project ........................................................ 220

7.5 Playing Audio ........................................................................... 222

Playing Audio App ................................................................. 223

Playing Audio Project ............................................................. 224

7.6 Playing Audio with a Background Service .............................. 229

Music Service App .................................................................. 229

Music Service Project .............................................................. 231

7.7 Recording Audio ...................................................................... 233

Recording Audio App ............................................................. 233

Recording Audio Project ......................................................... 234

7.8 Advanced Audio ....................................................................... 240

Built-in Audio Effects ............................................................. 240

Encoding ................................................................................ 242

7.9 Audio Synthesis ........................................................................ 245

Puredata Overview ................................................................. 247

Puredata Player App ............................................................... 249

Puredata Player Project ........................................................... 251
Preface | 12