Pro Java ME Apps: Building Commercial Quality Java ME Apps

355 Pages·2011·14.91 MB·English

by  Ovidiu Iliescu

Pro Java ME Apps
■ ■ ■
Ovidiu Iliescu
i
Pro Java ME Apps
Copyright © 2011 by Ovidiu Iliescu
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Mom, Dad, Grandpa – Thank you for everything. I love you.
Contents at a Glance
Contents .............................................................................................................. v
About the Author ................................................................................................ xi
About the Technical Reviewer .......................................................................... xii
Acknowledgments ........................................................................................... xiii
Introduction ...................................................................................................... xiv
■Chapter 1: Getting Started ............................................................................... 1(cid:2)
■Chapter 2: A Java ME Framework ................................................................. 25(cid:2)
■Chapter 3: Defining Our Data ......................................................................... 51(cid:2)
■Chapter 4: The Networking Module ............................................................... 63(cid:2)
■Chapter 5: The Persistence Module ............................................................... 93(cid:2)
■Chapter 6: The UI Module ............................................................................ 115(cid:2)
■Chapter 7: The Localization Module ............................................................ 155(cid:2)
■Chapter 8: Putting It All Together ................................................................ 169(cid:2)
■Chapter 9: Device Fragmentation ................................................................ 193(cid:2)
■Chapter 10: Optimizing Your Code .............................................................. 223(cid:2)
■Chapter 11: Adding Fine Touches and User Interaction Improvements ...... 251(cid:2)
■Chapter 12: Java ME Application Testing .................................................... 271(cid:2)
■Chapter 13: Advanced Java ME Graphics .................................................... 283(cid:2)
■Chapter 14: The Proper Java ME Mindset ................................................... 305(cid:2)
■Chapter 15: Java ME and the Future ........................................................... 325(cid:2)
■Chapter 16: Final Words .............................................................................. 337(cid:2)
Index ............................................................................................................... 341
iv
Contents
Contents at a Glance .......................................................................................... iv(cid:2)
About the Author ................................................................................................ xi(cid:2)
About the Technical Reviewer .......................................................................... xii(cid:2)
Acknowledgments ........................................................................................... xiii(cid:2)
Introduction ...................................................................................................... xiv

■Chapter 1: Getting Started ............................................................................... 1(cid:2)
(cid:2)
Java ME, Smartphones, and Feature Phones ......................................................................................................... 1
(cid:2)
Java ME’s Advantages ....................................................................................................................................... 1
(cid:2)
Java ME’s Disadvantages .................................................................................................................................. 2
(cid:2)
The Bottom Line ................................................................................................................................................. 3
(cid:2)
Creating a Java ME Application .............................................................................................................................. 3
(cid:2)
The Idea for the Application ............................................................................................................................... 4
(cid:2)
Goals, Features, Revenue Sources, and Target Devices .................................................................................... 4
(cid:2)
Identifying the Target Devices ........................................................................................................................... 6
(cid:2)
Identifying Java ME Technical Limitations ......................................................................................................... 7
(cid:2)
Regular Java ME Applications vs. Pro Java ME Applications .......................................................................... 13
(cid:2)
Writing Flexible Java ME Applications .................................................................................................................. 15
(cid:2)
Coding Defensively .......................................................................................................................................... 16
(cid:2)
Avoiding Wrong Assumptions .......................................................................................................................... 18
(cid:2)
Learning How to Handle Complexity ................................................................................................................ 18
(cid:2)
Trade-Offs Are Your Friends—Use Them Wisely ............................................................................................. 20
(cid:2)
Aim for a Loose and Decentralized Architecture ............................................................................................. 22
(cid:2)
Never Do On-Device What You Can Do Off-Device .......................................................................................... 23
(cid:2)
Summary .............................................................................................................................................................. 24
■Chapter 2: A Java ME Framework ................................................................. 25(cid:2)
(cid:2)
The Importance of Using a Framework ................................................................................................................. 25
(cid:2)
Why a Custom Framework for Each Application? ................................................................................................. 26
(cid:2)
Defining the Framework’s Structure ..................................................................................................................... 27
(cid:2)
Basic Object Types ................................................................................................................................................ 28
(cid:2)
Events .............................................................................................................................................................. 29
(cid:2)
Event Listeners ................................................................................................................................................ 31
v
■ CONTENTS
(cid:2)
Providers .......................................................................................................................................................... 31
(cid:2)
Consumers ....................................................................................................................................................... 32
(cid:2)
Managers ......................................................................................................................................................... 33
(cid:2)
Models and Controllers .................................................................................................................................... 33
(cid:2)
Views ............................................................................................................................................................... 34
(cid:2)
Common Objects ................................................................................................................................................... 35
(cid:2)
The EventController Class ................................................................................................................................ 35
(cid:2)
The EventControllerManager ........................................................................................................................... 37
(cid:2)
Core Objects and Classes ..................................................................................................................................... 39
(cid:2)
The Application Class ....................................................................................................................................... 39
(cid:2)
The EventManagerThreads Class ..................................................................................................................... 40
(cid:2)
The Bootstrap Class ......................................................................................................................................... 44
(cid:2)
A Simple Test Application ..................................................................................................................................... 45
(cid:2)
Summary .............................................................................................................................................................. 49
■Chapter 3: Defining Our Data ......................................................................... 51(cid:2)
(cid:2)
Why Implement the Model Interface? ................................................................................................................... 51
(cid:2)
Making Data Types Immutable ............................................................................................................................. 52
(cid:2)
Defining the Tweet Data Type ............................................................................................................................... 53
(cid:2)
Defining the TwitterUser Data Type ...................................................................................................................... 54
(cid:2)
Defining the TwitterServer Entity .......................................................................................................................... 55
(cid:2)
Defining the UserCredentials Data Type ............................................................................................................... 56
(cid:2)
Defining the TweetFilter Data Type ....................................................................................................................... 58
(cid:2)
Defining the Timeline Entity .................................................................................................................................. 58
(cid:2)
Choosing Intelligent Representations for Your Data ............................................................................................. 59
(cid:2)
Summary .............................................................................................................................................................. 61
■Chapter 4: The Networking Module ............................................................... 63(cid:2)
(cid:2)
Setting Up and Configuring the Library ................................................................................................................. 63
(cid:2)
Working with High-Level Objects ..................................................................................................................... 66
(cid:2)
Using Your Own Data Types ............................................................................................................................. 66
(cid:2)
Writing Our TwitterServer Implementation ........................................................................................................... 67
(cid:2)
Defining the General Structure ........................................................................................................................ 67
(cid:2)
Initializing a ServerImplementation Instance ................................................................................................... 68
(cid:2)
Providing Login Support ................................................................................................................................... 69
(cid:2)
Posting Tweets ................................................................................................................................................ 73
(cid:2)
Retrieving Tweets ............................................................................................................................................ 74
(cid:2)
The getMyProfile() and getProfileFor() Methods .............................................................................................. 85
(cid:2)
Best Practices for Java ME Networking ................................................................................................................ 86
(cid:2)
Do Not Reinvent the Wheel .............................................................................................................................. 86
(cid:2)
Mobile Internet Is Special ................................................................................................................................ 87
(cid:2)
Remember the Limitations of the Devices You’re Targeting ............................................................................ 88
(cid:2)
Support Network Throttling and Sleep Mode ................................................................................................... 88
(cid:2)
Transmitting Your Data Efficiently ................................................................................................................... 89
(cid:2)
Keeping the Networking Code Light ................................................................................................................ 90
(cid:2)
Be Independent ................................................................................................................................................ 91
(cid:2)
Summary .............................................................................................................................................................. 91
vi
■ CONTENTS
■Chapter 5: The Persistence Module ............................................................... 93(cid:2)
(cid:2)
Understanding Java ME Persistence Options ....................................................................................................... 93
(cid:2)
Designing the Persistence Module ....................................................................................................................... 95
(cid:2)
The Persistence Providers ............................................................................................................................... 96
(cid:2)
RecordReaders and RecordWriters .................................................................................................................. 97
(cid:2)
Serializers and Deserializers ........................................................................................................................... 99
(cid:2)
Persistence Helpers ....................................................................................................................................... 100
(cid:2)
Implementing the Core Architecture ................................................................................................................... 100
(cid:2)
Implementing Serializers and Deserializers .................................................................................................. 101
(cid:2)
Implementing RecordReaders and RecordWriters ......................................................................................... 103
(cid:2)
Implementing the PersistenceProvider .......................................................................................................... 104
(cid:2)
Testing the Code ............................................................................................................................................ 106
(cid:2)
Writing Persistence Helpers ................................................................................................................................ 107
(cid:2)
Using the Module in a Real-Life Scenario ........................................................................................................... 112
(cid:2)
Taking the Module Further .................................................................................................................................. 113
(cid:2)
Summary ............................................................................................................................................................ 113
■Chapter 6: The UI Module ............................................................................ 115(cid:2)
(cid:2)
Why Create a Custom UI Module? ....................................................................................................................... 116
(cid:2)
Understanding the Basics of Creating a UI Module ............................................................................................. 116
(cid:2)
Widgets .......................................................................................................................................................... 117
(cid:2)
Containers ...................................................................................................................................................... 118
(cid:2)
Clipping Rectangles ....................................................................................................................................... 120
(cid:2)
Views ............................................................................................................................................................. 124
(cid:2)
Themes .......................................................................................................................................................... 124
(cid:2)
Handling User Interaction .............................................................................................................................. 126
(cid:2)
Implementing Basic Widget Support .................................................................................................................. 127
(cid:2)
The BaseWidget Class ................................................................................................................................... 127
(cid:2)
BaseContainerWidget and BaseContainerManager ....................................................................................... 130
(cid:2)
Implementing Concrete Widgets ......................................................................................................................... 135
(cid:2)
The VerticalContainer and HorizontalContainer Classes ................................................................................ 135
(cid:2)
The SimpleTextButton Class .......................................................................................................................... 139
(cid:2)
The StringItem Class ...................................................................................................................................... 141
(cid:2)
InputStringItem .............................................................................................................................................. 143
(cid:2)
GameCanvasView .......................................................................................................................................... 146
(cid:2)
Testing the UI Module ......................................................................................................................................... 147
(cid:2)
Implementing UIs on Touch-Only Devices .......................................................................................................... 149
(cid:2)
Final Words About the UI Module ........................................................................................................................ 151
(cid:2)
Summary ............................................................................................................................................................ 153
■Chapter 7: The Localization Module ............................................................ 155(cid:2)
(cid:2)
Understanding the Features of a Good Localization Module ............................................................................... 155
(cid:2)
Understanding Native Java ME Localization ....................................................................................................... 156
(cid:2)
Adding Custom Localization Support to a Java ME Application .......................................................................... 157
(cid:2)
Processing Localization Files ......................................................................................................................... 159
(cid:2)
Loading Localization Data on the Device ....................................................................................................... 161
(cid:2)
Testing the Localization Module ......................................................................................................................... 164
(cid:2)
Implementing Advanced Localization Features .................................................................................................. 165
(cid:2)
Summary ............................................................................................................................................................ 168
vii
■ CONTENTS
■Chapter 8: Putting It All Together ................................................................ 169(cid:2)
(cid:2)
Jump-Starting the Application ............................................................................................................................ 169
(cid:2)
Implementing the FlowController ........................................................................................................................ 170
(cid:2)
Implementing the TweetsController .................................................................................................................... 173
(cid:2)
Implementing the WelcomeScreenController and the WelcomeForm ................................................................ 175
(cid:2)
Implementing the MainForm and MainScreenController .................................................................................... 179
(cid:2)
Implementing the SettingsScreenController and the SettingsForm ................................................................... 184
(cid:2)
Implementing the EVT Class ............................................................................................................................... 188
(cid:2)
Improving the Application ................................................................................................................................... 189
(cid:2)
Improving Error Handling ............................................................................................................................... 189
(cid:2)
Increasing Functionality ................................................................................................................................. 191
(cid:2)
Improving the UI Framework ......................................................................................................................... 191
(cid:2)
Summary ............................................................................................................................................................ 192
■Chapter 9: Device Fragmentation ................................................................ 193(cid:2)
(cid:2)
Hardware Fragmentation .................................................................................................................................... 194
(cid:2)
CPU Power ..................................................................................................................................................... 194
(cid:2)
RAM ............................................................................................................................................................... 197
(cid:2)
Screen ............................................................................................................................................................ 199
(cid:2)
Other Hardware Considerations ..................................................................................................................... 201
(cid:2)
Capabilities Fragmentation ................................................................................................................................. 202
(cid:2)
API Inconsistencies ............................................................................................................................................. 206
(cid:2)
Localized API Inconsistencies ........................................................................................................................ 207
(cid:2)
Global API Inconsistencies ............................................................................................................................. 210
(cid:2)
Inconsistencies Open for Interpretation ......................................................................................................... 212
(cid:2)
Porting Frameworks ........................................................................................................................................... 214
(cid:2)
The Preprocessor ........................................................................................................................................... 214
(cid:2)
The Device Database ..................................................................................................................................... 216
(cid:2)
The Build Engine ............................................................................................................................................ 216
(cid:2)
The Abstraction API ........................................................................................................................................ 217
(cid:2)
Multi-platform Support .................................................................................................................................. 218
(cid:2)
Utility Code and Tools .................................................................................................................................... 218
(cid:2)
UI Library ........................................................................................................................................................ 219
(cid:2)
Customer Support .......................................................................................................................................... 219
(cid:2)
Code License .................................................................................................................................................. 220
(cid:2)
Cross-Development and Porting Tools ................................................................................................................ 220
(cid:2)
Summary ............................................................................................................................................................ 221
■Chapter 10: Optimizing Your Code .............................................................. 223(cid:2)
(cid:2)
A Crash Course in Optimizing Code .................................................................................................................... 224
(cid:2)
Code Optimization Techniques ........................................................................................................................... 226
(cid:2)
Fast Code Path Switching .............................................................................................................................. 226
(cid:2)
Avoid Redundancy ......................................................................................................................................... 227
(cid:2)
Use Locality to Your Advantage ..................................................................................................................... 227
(cid:2)
Optimize Your Math ....................................................................................................................................... 228
(cid:2)
Unroll Loops ................................................................................................................................................... 231
(cid:2)
Inline Code ..................................................................................................................................................... 231
(cid:2)
Optimize Loop-Related Math ......................................................................................................................... 232
(cid:2)
Keep Your Loops Conditional-Free ................................................................................................................. 233
viii
■ CONTENTS
(cid:2)
Eliminate Special Iterations from Your Loops ................................................................................................ 234
(cid:2)
Use Loop Fission ............................................................................................................................................ 235
(cid:2)
Avoiding High-Level Language Features ............................................................................................................ 235
(cid:2)
Stick to the Basics ......................................................................................................................................... 236
(cid:2)
Avoid Unnecessary Object Creation ............................................................................................................... 237
(cid:2)
Optimize Memory Access .............................................................................................................................. 240
(cid:2)
Algorithm Optimization Techniques .................................................................................................................... 241
(cid:2)
Comparing Algorithms ................................................................................................................................... 241
(cid:2)
Improving Your Algorithms ............................................................................................................................ 243
(cid:2)
Summary ............................................................................................................................................................ 250
■Chapter 11: Adding Fine Touches and User Interaction Improvements ...... 251(cid:2)
(cid:2)
Adding Fine Touches to Your Application ........................................................................................................... 251
(cid:2)
Understanding Fine Touches ......................................................................................................................... 252
(cid:2)
Adding Proper In-Application Help ................................................................................................................. 253
(cid:2)
Adding Contextual Information ...................................................................................................................... 255
(cid:2)
Adding Proper Feedback ................................................................................................................................ 256
(cid:2)
Adding Adaptive Text Capabilities ................................................................................................................. 257
(cid:2)
Adding History and Auto-Complete Support .................................................................................................. 259
(cid:2)
Adding Intent Detection ................................................................................................................................. 260
(cid:2)
Synchronizing Your Data Between Devices ................................................................................................... 261
(cid:2)
Improving User Interaction ................................................................................................................................. 262
(cid:2)
Eliminating User Confusion ............................................................................................................................ 263
(cid:2)
Keeping the Interface Simple ......................................................................................................................... 264
(cid:2)
Allowing Customers to Reach You Easily ....................................................................................................... 266
(cid:2)
Creating Nonmobile Versions of Your Application ......................................................................................... 267
(cid:2)
Deploying Continuous Application Updates ................................................................................................... 267
(cid:2)
Adding Skin Support ...................................................................................................................................... 268
(cid:2)
Advertising Related Products ......................................................................................................................... 269
(cid:2)
Deciding Which Fine Touches and Improvements to Implement ........................................................................ 270
(cid:2)
Summary ............................................................................................................................................................ 270
■Chapter 12: Java ME Application Testing .................................................... 271(cid:2)
(cid:2)
Gathering Debug Information .............................................................................................................................. 271
(cid:2)
Performing Unit Testing ...................................................................................................................................... 273
(cid:2)
Solving Common Unit Test–Related Problems ............................................................................................... 274
(cid:2)
Gathering Quality Debug Data ........................................................................................................................ 275
(cid:2)
Running the Tests in a Desktop Environment ................................................................................................ 276
(cid:2)
Performing Visual Debugging ............................................................................................................................. 276
(cid:2)
Performing Battery Testing ................................................................................................................................. 277
(cid:2)
Testing the Application in a Variety of Scenarios ............................................................................................... 279
(cid:2)
Testing Performance Improvement and Optimization Techniques ..................................................................... 280
(cid:2)
Summary ............................................................................................................................................................ 281
■Chapter 13: Advanced Java ME Graphics .................................................... 283(cid:2)
(cid:2)
Using Pre-rendered Graphics .............................................................................................................................. 284
(cid:2)
Using Image Masking ......................................................................................................................................... 287
(cid:2)
Using Image Blending Techniques ...................................................................................................................... 289
(cid:2)
Rotating Images .................................................................................................................................................. 294
(cid:2)
Resizing Images .................................................................................................................................................. 300
ix