Beginning Java™ Google App Engine

249 Pages·2010·3.36 MB·English

by  Kyle Roche

™
Beginning Java
Google App Engine

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Kyle Roche
Jeff Douglas
Beginning Java™ Google App Engine
Copyright © 2009 by Kyle Roche and Jeff Douglas
All rights reserved. No part of this work may be reproduced or transmitted in any form or by any means,
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ISBN-13 (pbk): 978-1-4302-2553-9
ISBN-13 (electronic): 978-1-4302-2554-6
Printed and bound in the United States of America 9 8 7 6 5 4 3 2 1
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Lead Editor: Steve Anglin
Developmental Editor: Tom Welsh
Technical Reviewer: Kunal Mittal
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Jeffrey Pepper, Frank Pohlmann, Douglas Pundick, Ben Renow-Clarke, Dominic Shakeshaft,
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There’s an Irish saying . . . no man can prosper without his woman’s leave. —KR
To Cathy, who has touched not only my heart,
but the hearts of so many that will never remember her. I love you. —JD
Contents at a Glance
Foreword.................................................................................................................xiii
About the Authors.....................................................................................................xv
About the Technical Reviewer................................................................................xvii
Acknowledgments...................................................................................................xix
Introduction.............................................................................................................xxi
Chapter 1: Beginning Google App Engine for Java....................................................1
Chapter 2: Introduction to App Engine.......................................................................7
Chapter 3: Getting Started with Google App Engine for Java...................................25
Chapter 4: Servlet Container and Frameworks........................................................43
Chapter 5: Developing Your Application...................................................................89
Chapter 6: Authenticating Users.............................................................................123
Chapter 7: Using the App Engine Datastore............................................................135
Chapter 8: App Engine Services.............................................................................169
Chapter 9: Administration and Integration.............................................................197
Index.......................................................................................................................221
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Contents
Foreword.................................................................................................................xiii
About the Authors.....................................................................................................xv
About the Technical Reviewer................................................................................xvii
Acknowledgments...................................................................................................xix
Introduction.............................................................................................................xxi
Chapter 1: Beginning Google App Engine for Java....................................................1
Cloud Computing and App Engine.................................................................................................................1
Find More Time to Innovate......................................................................................................................4
What You’ll Learn in This Book.................................................................................................................5
Summary.......................................................................................................................................................6
Chapter 2: Introduction to App Engine.......................................................................7
App Engine Architecture................................................................................................................................7
Being a Good Neighbor With Quotas..............................................................................................................9
Billable and Fixed Quotas.......................................................................................................................10
Detailed Resource Quotas......................................................................................................................12
Components of an App Engine Application..................................................................................................22
Summary.....................................................................................................................................................23
Chapter 3: Getting Started with Google App Engine for Java...................................25
Where Do We Start?....................................................................................................................................25
Create Your First App Engine Project...........................................................................................................30
Local Development Server...........................................................................................................................37
Summary.....................................................................................................................................................42
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■ CONTENTS
Chapter 4: Servlet Container and Frameworks........................................................43
Choosing a Framework................................................................................................................................43
Servlets and JavaServer Pages...................................................................................................................46
Views......................................................................................................................................................46
Model......................................................................................................................................................59
Controller................................................................................................................................................64
Deployment Descriptor...........................................................................................................................69
PersistenceManager...............................................................................................................................69
Spring MVC..................................................................................................................................................70
Server Configuration...............................................................................................................................71
Views......................................................................................................................................................72
Adobe Flex...................................................................................................................................................74
Server Configuration...............................................................................................................................76
Client-Side Code.....................................................................................................................................79
Server-Side Code....................................................................................................................................83
Summary.....................................................................................................................................................88
Chapter 5: Developing Your Application...................................................................89
Functional Specifications............................................................................................................................89
Timecard UI Mock-up.............................................................................................................................90
Technical Specifications..............................................................................................................................91
Authentication........................................................................................................................................91
Presentation...........................................................................................................................................91
Persistence.............................................................................................................................................92
Using Google Web Toolkit............................................................................................................................92
Creating Your Project..............................................................................................................................93
Running the Initial Starter Application....................................................................................................96
Developing Your Application........................................................................................................................97
Required Imports..................................................................................................................................101
Coding Your UI......................................................................................................................................102
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■ CONTENTS

Adding Your Styles...............................................................................................................................107
Modifying Your Hosted Page................................................................................................................107
Running Your Application.....................................................................................................................108
Handling Client-Side Events.................................................................................................................108
Summary...................................................................................................................................................121
Chapter 6: Authenticating Users.............................................................................123
Introducing Google Accounts.....................................................................................................................123
Restricting Access to Resources..........................................................................................................124
Users API..............................................................................................................................................125
Development Mode...............................................................................................................................126
Adding Authentication for Your Application...............................................................................................127
LoginInfo Class.....................................................................................................................................128
LoginService and LoginServiceAsync Interfaces..................................................................................129
Google Accounts Login Implementation...............................................................................................130
Modifying the Deployment Descriptor..................................................................................................131
Modifying the User Interface................................................................................................................131
Summary...................................................................................................................................................133
Chapter 7: Using the App Engine Datastore............................................................135
Introducing the App Engine Datastore.......................................................................................................135
Working with Entities.................................................................................................................................136
Classes and Fields................................................................................................................................137
CRUDing Entities...................................................................................................................................143
Performing Queries with JDOQL................................................................................................................145
Filtering Queries...................................................................................................................................146
Sorting Queries.....................................................................................................................................147
Query Ranges.......................................................................................................................................147
Using Indexes............................................................................................................................................147
Building Indexes...................................................................................................................................148
Creating Indexes In Development Mode...............................................................................................148
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Using Transactions....................................................................................................................................149
Finishing Up Your Application....................................................................................................................150
Making Remote Procedure Calls with GWT RPC...................................................................................150
Creating Your Data Service...................................................................................................................156
Modifying the Deployment Descriptor..................................................................................................161
Invoking the Service from the GWT Client............................................................................................161
Displaying Timecard Entries.................................................................................................................166
Summary...................................................................................................................................................168
Chapter 8: App Engine Services.............................................................................169
Setting up the Project................................................................................................................................169
Memcache Service....................................................................................................................................171
URL Fetch Service.....................................................................................................................................175
Images Service..........................................................................................................................................178
Creating the Java Classes....................................................................................................................179
Writing the ImageObject Class.............................................................................................................180
Writing the PersistenceManagerFactory Class.....................................................................................182
Writing the ImageSource Class............................................................................................................182
Writing the ImageTransform Class.......................................................................................................183
Completing the Application..................................................................................................................186
Testing the Service...............................................................................................................................187
Mail API......................................................................................................................................................189
XMPP Service............................................................................................................................................192
Summary...................................................................................................................................................195
Chapter 9: Administration and Integration.............................................................197
Managing Your App Engine Application.....................................................................................................197
The Application Dashboard...................................................................................................................199
Application Versioning..........................................................................................................................203
Analyzing Log Files...............................................................................................................................204
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Integration.................................................................................................................................................206
Integration with Google Wave...............................................................................................................206
Integration with Salesforce.com...........................................................................................................214
Summary...................................................................................................................................................218
Index.......................................................................................................................221
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