Practical Android: 14 Complete Projects on Advanced Techniques and Approaches

253 Pages·2018·5.11 MB·English

by  Mark Wickham (auth.)

Practical
Android
14 Complete Projects on Advanced
Techniques and Approaches
—
Mark Wickham
Practical Android
14 Complete Projects on Advanced
Techniques and Approaches
Mark Wickham
Practical Android: 14 Complete Projects on Advanced Techniques and Approaches
Mark Wickham
Dallas, Texas, USA
ISBN-13 (pbk): 978-1-4842-3332-0 ISBN-13 (electronic): 978-1-4842-3333-7
https://doi.org/10.1007/978-1-4842-3333-7
Library of Congress Control Number: 2017964267
Copyright © 2018 by Mark Wickham
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Printed on acid-free paper
To my parents, who helped me discover computers and software when I was young.
Contents
About the Author ���������������������������������������������������������������������������������������������������xiii
About the Technical Reviewers �������������������������������������������������������������������������������xv
Acknowledgments �������������������������������������������������������������������������������������������������xvii
Preface �������������������������������������������������������������������������������������������������������������������xix
Introduction ������������������������������������������������������������������������������������������������������������xxi
■ Chapter 1: Introduction to JSON ����������������������������������������������������������������������������1
1.1 Introduction .............................................................................................................1
1.2 Chapter Projects ......................................................................................................2
1.3 JSON Overview .......................................................................................................2
1.4 JSON and Android ...................................................................................................3
1.5 Designing JSON ......................................................................................................4
JSON Sample File ...................................................................................................................................5
Validating JSON ......................................................................................................................................6
Text File Encoding ...................................................................................................................................7
1.6 Common JSON Operations ......................................................................................7
Setting a JSON Value in a JSON Object ..................................................................................................8
Getting a JSON Value from a JSON Object ..............................................................................................9
Creating a JSON File Programmatically ..................................................................................................9
v
vi Contents
Reading and Parsing a JSON File .........................................................................................................10
Printing JSON Strings ...........................................................................................................................11
Removing JSON Arrays .........................................................................................................................11
1.7 J SON Alternatives .................................................................................................13
G SON ....................................................................................................................................................13
Jackson ................................................................................................................................................14
1.8 R eferences ............................................................................................................15
A ndroid JSON .......................................................................................................................................15
Google GSON ........................................................................................................................................15
Third Party ............................................................................................................................................15
■ Chapter 2: Connectivity ���������������������������������������������������������������������������������������17
2.1 Introduction ...........................................................................................................17
2.2 Chapter Projects ....................................................................................................17
2.3 Connectivity Basics ...............................................................................................18
2.4 A ndroid HTTP Options............................................................................................19
2.5 Connectivity Status ...............................................................................................22
Using the Built in APIs...........................................................................................................................22
WiFi Broadcast Receiver .......................................................................................................................23
2.6 S erver Reachability ...............................................................................................24
Pinging with ICMP ................................................................................................................................25
Pinging with HTTP ................................................................................................................................26
HTTP Status Codes ...............................................................................................................................27
Blocked Protocols and URL Redirects...................................................................................................28
Generating 204 Responses ...................................................................................................................29
2.7 C onnections App ...................................................................................................29
C onnections App Overview ...................................................................................................................30
Connections Project ..............................................................................................................................31
Connections App Configuration ............................................................................................................31
MainActivity.java ...................................................................................................................................32
Interpreting Reachability Results..........................................................................................................36
Contents vii
2.8 S plash App ............................................................................................................37
S plash App Overview ............................................................................................................................38
Splash Project .......................................................................................................................................39
Splash.xml ............................................................................................................................................39
SplashActivity.java ................................................................................................................................41
2.9 E ssential Tools .......................................................................................................45
2.10 References ..........................................................................................................45
Android HTTP and Connectivity ............................................................................................................45
ApacheHttpClient ..................................................................................................................................46
OkHttp ...................................................................................................................................................46
Tools .....................................................................................................................................................46
■ Chapter 3: Lazy Loading Images �������������������������������������������������������������������������47
3.1 Introduction ...........................................................................................................47
3.2 Chapter Projects ....................................................................................................47
3.3 Lazy Loading Libraries ..........................................................................................48
3.4 Lazy Loading Architecture .....................................................................................49
M emory Cache ......................................................................................................................................50
Disk Cache ............................................................................................................................................51
3.5 Choosing a Library ................................................................................................52
G oogle Volley ........................................................................................................................................53
Square Picasso .....................................................................................................................................54
Facebook Fresco ..................................................................................................................................55
3.6 H andling Image Assets ..........................................................................................56
Size vs. Quality Tradeoff .......................................................................................................................57
Image Downsampling ...........................................................................................................................58
Aspect Ratio .........................................................................................................................................59
3.7 L azy Loading App ..................................................................................................60
Lazy Loading App Overview ..................................................................................................................61
Lazy Loading Project ............................................................................................................................62
XML Layout Files ..................................................................................................................................69
ImageLoader.java ..................................................................................................................................71
viii Contents
M emoryCache.java ...............................................................................................................................73
FileCache.java .......................................................................................................................................75
Adapters ...............................................................................................................................................76
Lazy List Adapter ..................................................................................................................................76
Lazy Grid Adapter .................................................................................................................................78
Lazy Gallery Adapter .............................................................................................................................81
3.8 R eferences ............................................................................................................83
Android and Java References ...............................................................................................................83
Third-Party Lazy Loading Libraries .......................................................................................................84
■ Chapter 4: Remote Crash Logs ����������������������������������������������������������������������������85
4.1 Introduction ...........................................................................................................85
4.2 Chapter Project .....................................................................................................85
4.3 Remote Crash Log Solutions .................................................................................86
How Crash Logging Works ....................................................................................................................88
4.4 A pp Crash Report for Android ................................................................................89
A CRA Overview .....................................................................................................................................89
4.5 A CRA Back-End Server ..........................................................................................91
4.6 Open Street Map for Android .................................................................................92
4.7 Remote Crash Log App ..........................................................................................95
Remote Crash Log App Overview .........................................................................................................95
Remote Crash Log Project ....................................................................................................................97
PHP Self-Hosted Script .......................................................................................................................101
4.8 R eferences ..........................................................................................................104
A ndroid ...............................................................................................................................................104
Google Firebase ..................................................................................................................................104
OSMdroid ............................................................................................................................................104
Third Party ..........................................................................................................................................104
■ Chapter 5: Uploading and Emailing �������������������������������������������������������������������105
5.1 Introduction .........................................................................................................105
5.2 Chapter Projects ..................................................................................................105
5.3 Overview .............................................................................................................106
Contents ix
5.4 Server Spinner: Server Setup ..............................................................................107
5.5 Server Spinner App .............................................................................................110
Server Spinner App Overview .............................................................................................................110
Server Spinner Project........................................................................................................................111
Deleting an Item .................................................................................................................................117
Utils.java .............................................................................................................................................118
Uploading an Item ...............................................................................................................................118
5.6 M obile Email .......................................................................................................120
5.7 Mobile Email Approaches ....................................................................................120
5.8 Email Protocols ...................................................................................................121
5.9 A ndroid Email Clients ..........................................................................................122
5.10 Emailing App: AWS Server Setup.......................................................................122
5.11 Emailing App .....................................................................................................124
A ndroid Intents ...................................................................................................................................124
JavaMail API .......................................................................................................................................125
External AWS Interface .......................................................................................................................125
Emailing App Overview .......................................................................................................................125
Emailing Project ..................................................................................................................................126
MainActivity.java .................................................................................................................................127
GMailSender.java ................................................................................................................................132
JSSEProvider.java ...............................................................................................................................133
5.12 R eferences ........................................................................................................133
U ploading Files ...................................................................................................................................133
Email ...................................................................................................................................................133
■ Chapter 6: Push Messaging �������������������������������������������������������������������������������135
6.1 Introduction .........................................................................................................135
6.2 Chapter Projects ..................................................................................................136
6.3 Push Messaging Overview ..................................................................................136
P ush Technologies ..............................................................................................................................137
How Push Messaging Works ..............................................................................................................139
Choosing a Technology .......................................................................................................................140
x Contents
6.4 Push Messaging Services ...................................................................................142
P ush Service Advantages ...................................................................................................................142
Choosing a Push Service ....................................................................................................................143
Services Setup Steps..........................................................................................................................144
6.5 Firebase Cloud Messaging ..................................................................................145
G CM/FCM Migration ............................................................................................................................145
FCM Setup ..........................................................................................................................................146
FCM Quickstart App ............................................................................................................................148
FCM App .............................................................................................................................................149
FCM Project ........................................................................................................................................150
Application Server Setup ....................................................................................................................154
FCM Upstream Messaging ..................................................................................................................159
6.6 Open Source Push Messaging with MQTT ..........................................................161
M QTT Introduction ..............................................................................................................................161
MQTT App ...........................................................................................................................................163
MQTT Project ......................................................................................................................................164
MQTT Message Brokers ......................................................................................................................169
MQTT Broker Setup for AWS ...............................................................................................................169
Sending Messages with MQTT Web Clients ........................................................................................170
MQTT Wrap Up ....................................................................................................................................171
6.7 R eferences ..........................................................................................................171
Firebase Cloud Messaging (FCM) .......................................................................................................171
MQTT Push Messaging .......................................................................................................................172
■ Chapter 7: Android Audio ����������������������������������������������������������������������������������173
7.1 Introduction .........................................................................................................173
7.2 Chapter Projects ..................................................................................................175
7.3 A udio Overview ...................................................................................................176
API and Class Summary .....................................................................................................................176
Choosing the Right API .......................................................................................................................178