This document discusses how to use Google Datastore for Android apps. It provides an overview of Google Datastore and its features as a non-relational cloud database. It then describes setting up the development environment in Eclipse and Google App Engine. It outlines the project structure and code for creating a sample app using the Video class and defining APIs. It also covers deploying the app to App Engine and generating an Android client library to access the APIs.

1. Using Google Datastore for
Android apps
Gaurang Kanvinde
(gaurang.kanvinde@drawtyme.com)
An example of how Google Datastore
was used for DrawTyme
(http://drawty.me/ua44g)
+

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Overview of Google Datastore
• Non-relational database
• Cloud based
• Ready to use
• Requires Google App Engine and Google Endpoints
– Very inexpensive and simple to use
– Can be programmed in many languages – Java, Python, etc
– Extensive documentation available

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The Development Environment
• Eclipse for Java EE - Download and install
• Google Plugin for Eclipse – Instructions to install

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Setting up Google App Engine
• Create a project on Google App Engine - Link to Console
• Remember it’s Project-ID

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The nuts and bolts
• Two main directories
– src
• Contains all the code of the app
– war
• Contains a sub-directory named WEB-INF
– Contains the compiled binaries of the code in “src”
– Contains other dependencies
– Everything else that goes into the app
• Contents of this directory will be deployed to the Google App Engine
– index.html (if any, will go here)
• Code available at: DrawTymeExample.zip

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Understanding the code
• The Video class

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Writing the API
• Defining the API class with @Api annotation

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Writing the API
• Adding authenticated methods

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Writing the API
• Adding unauthenticated methods

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Preparing to Deploy
• Write app-ID of your project in war/WEB-INF/appengine-
web.xml

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Setting up Datastore Indexes
• war/WEB-INF/datastore-indexes.xml
– If you get the contents of this file wrong, Google App Engine suggests
the correct content for you!

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A quick peek at the Web-app
• war/js/backend.js
– Initialising the API

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A quick peek at the Web-app
• war/js/backend.js
– Calling API functions

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Deploying to App Engine
• Use Google Plugin button
– Deploy to App Engine
– Sign-in to the App Engine is required

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It works!

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Porting to Android
• AppEngine SDK has all the tools!
– Use endpoints.cmd or endpoints.sh
• Eg: $PATH_TO_SDK/bin/endpoints.cmd get-client-lib
com.example.api.classname
– Android code will be generated and stored in myapi-v1-java.zip

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Locating the Android code for Endpoints

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And we are done!
• Have fun using Google App Engine!
• Contact me
Gaurang.kanvinde@drawtyme.com
Twitter: @gaurangrk
• DrawTyme
http://www.drawtyme.com
Twitter: @drawtyme
Facebook: https://www.facebook.com/drawtyme
Blog: http://blog.drawtyme.com