Post on 27-Aug-2020
Developing Android REST ClientApplications
Tomche Delev
Java User GroupMacedoniawww.jug.mk
December 18, 2011
REST Client Applications
REST: A broadly adopted architecture style
A large number of REST APIs are available
Why develop them if mobile friendly web sitesalreadyexist?
Tomche Delev (JUGMK) Android REST Applications December 2010 2 / 20
REST Client Applications
REST: A broadly adopted architecture style
A large number of REST APIs are available
Why develop them if mobile friendly web sitesalreadyexist?
Tomche Delev (JUGMK) Android REST Applications December 2010 2 / 20
REST Client Applications
REST: A broadly adopted architecture style
A large number of REST APIs are available
Why develop them if mobile friendly web sitesalreadyexist?
Tomche Delev (JUGMK) Android REST Applications December 2010 2 / 20
REST Client Applications
REST: A broadly adopted architecture style
A large number of REST APIs are available
Why develop them if mobile friendly web sitesalreadyexist?
Tomche Delev (JUGMK) Android REST Applications December 2010 2 / 20
Incorrect Implementation of RESTMethods
”I haven’t failed, I’ve found 10,000 waysthat don’t work.”
- Thomas Alva Edison
Tomche Delev (JUGMK) Android REST Applications December 2010 3 / 20
The Incorrect Implementation of RESTMethos
Tomche Delev (JUGMK) Android REST Applications December 2010 4 / 20
Whats wrong with this approach?
The operating system may shut down the process
Data is not persistently stored
Tomche Delev (JUGMK) Android REST Applications December 2010 5 / 20
Whats wrong with this approach?
The operating system may shut down the process
Data is not persistently stored
Tomche Delev (JUGMK) Android REST Applications December 2010 5 / 20
Whats wrong with this approach?
The operating system may shut down the process
Data is not persistently stored
Tomche Delev (JUGMK) Android REST Applications December 2010 5 / 20
Implementing REST Methods
Theres a way to do it better ... find it.
- Thomas Alva Edison
Tomche Delev (JUGMK) Android REST Applications December 2010 6 / 20
Implementing REST Methods using aService API
Tomche Delev (JUGMK) Android REST Applications December 2010 7 / 20
Implementing REST Methods using aService API
Tomche Delev (JUGMK) Android REST Applications December 2010 8 / 20
The Processor (POST & PUT)
Tomche Delev (JUGMK) Android REST Applications December 2010 9 / 20
The Processor (DELTE & GET)
Tomche Delev (JUGMK) Android REST Applications December 2010 10 / 20
Implementing REST Methods using aService API
Tomche Delev (JUGMK) Android REST Applications December 2010 11 / 20
The Service
The role of the service
Forward path: receives the Intent sent by the Service
Helper and starts the corresponding REST Method
Return path: handles the Processor callback andinvokes the Service Helper binder callback
It can implement a queue of downloads
Tomche Delev (JUGMK) Android REST Applications December 2010 12 / 20
Implementing REST Methods using aService API
Tomche Delev (JUGMK) Android REST Applications December 2010 13 / 20
The Service Helper
Singleton which exposes a simple asynchronous APIto be used by the user interfacePrepare and send the Service request
Check if the method is already pendingCreate the request IntentAdd the operation type and a unique request idAdd the method specific parametersAdd the binder callbackCall startService(Intent)
Return the request idHandle the callback from the service
Dispatch callbacks to the user interface listeners
Tomche Delev (JUGMK) Android REST Applications December 2010 14 / 20
Implementing REST Methods using aService API
Tomche Delev (JUGMK) Android REST Applications December 2010 15 / 20
Handling the REST Method in an Activity
Add an operation listener in onResume and removeit in onPauseConsider these cases:
The Activity is still active when the request completesThe Activity is paused then resumed and then therequest completesThe Activity is paused when the request completes andthen Activity is resumed
The CursorAdapter handles the ContentProvidernotification by implementing a ContentObserver
Tomche Delev (JUGMK) Android REST Applications December 2010 16 / 20
Implementing REST Methods using aService API
Tomche Delev (JUGMK) Android REST Applications December 2010 17 / 20
Conclusions
”To have a great idea, have a lot of them.”&”The value of an idea lies in the using of it.”
- Thomas Alva Edison
Tomche Delev (JUGMK) Android REST Applications December 2010 18 / 20
Conclusions
Do not implement REST methods inside Activities
Start long running operations from a Service
Persist early & persist often
Minimize the network usage
Tomche Delev (JUGMK) Android REST Applications December 2010 19 / 20
Questions
Thanks for listenting.Questions?POST questions HTTP/1.1Host: jug.mkUser-Agent: JavaDay participantContent-Length: reasonableContent-Type: android-related/java
Tomche Delev (JUGMK) Android REST Applications December 2010 20 / 20