Bruce Scharlau, University of Aberdeen, 2010 Android Storage & SMS Apps Mobile Computing Unless otherwise stated, images are from android sdk See Unlocking

Bruce Scharlau, University of Aberdeen, 2010

Android Storage & SMS Apps

Mobile Computing

Unless otherwise stated, images are from android sdk

See Unlocking Android (Ch 5) for more details

There are several options for storage of data with Android

• We can put data into a preferences file.

• We can put data into a ‘normal’ file.

• We can send data across the network to a service.

• We can use a local database on the handset.


Preference files are a light-weight option

• Call Context.getSharedPreferences() to read and write values as key-value pairs.

• Use Activity.getPreferences() with no name to keep them private to the calling activity


These are not sharable across applications, unless you expose them as a ‘content provider’.

We can write larger data to file

• You can either write to a new file, or to a pre-included file under res/raw/mydata

• To can read data from a file, call Context.openFileInput() and pass it the local name and path of the file. It returns a standard Java FileInputStream object.

• To write to a file, call Context.openFileOutput() with the name and path. It returns a FileOutputStream object.


You can only access files available to the application

File writing is similar to what you’ve done before


Source: unlocking android, p 159

We can place data elsewhere on the network

Use a web service to store data elsewhere – save photos to flickr, files to some other app in the cloud.


Can save files automatically, or at user discretion with time values, etc. (twitter, email apps, or photo capture)

We can also persist data to a db

• Android API uses the built-in SQLite db.

• Each db is private to the application. In principle you could expose the data, if you expose the application as a content provider.

• All databases, SQLite and others, are stored on the device in /data/data/package_name/databases.


Android Notepad tutorial uses database


Useful db helper class for access and crud details

Context Menu is special

Acquire context menu by holding down selection key (long press on touch), which then pops up context menu


Unlocking Android db example covers more complex example


Stores locations to database within application as objects

Unlocking Android app uses db helper classes with sql


public static class Location {

public long id; public long lastalert; public int alertenabled; public String zip; // include city and region because geocode is expensive public String city; public String region;

public Location() { }

public Location(final long id, final long lastalert, final int alertenabled, final String zip, final String city, final String region) { this.id = id; this.lastalert = lastalert; this.alertenabled = alertenabled; this.zip = zip; this.city = city; this.region = region; }

Source: unlocking android, code

Part of DBHelper class showingLocation object

Class also holds crud details to map object to sql

Unlocking Android app maps objects to sql for ease


public void insert(final Location location) { ContentValues values = new ContentValues(); values.put("zip", location.zip); values.put("city", location.city); values.put("region", location.region); values.put("lastalert", location.lastalert); values.put("alertenabled", location.alertenabled); this.db.insert(DBHelper.DB_TABLE, null, values); }

public void update(final Location location) { ContentValues values = new ContentValues(); values.put("zip", location.zip); values.put("city", location.city); values.put("region", location.region); values.put("lastalert", location.lastalert); values.put("alertenabled", location.alertenabled); this.db.update(DBHelper.DB_TABLE, values, "_id=" + location.id, null); }

Source: unlocking android, code

Mapping makes coding easier

SQLite provides advanced db features

• There is transaction support

• You can use prepared statements based on java.sql and set items as have done before – faster and more secure

• You have a cursor to keep track of location within a resultset


Can map objects to db

Enables off network use and can sync later when connected


Might be pushing limits of device though with extra classes and memory usage

Can read items from network as xml and convert to objects, which map to db

Storage Summary

• Can use preferences for each app

• Can write/read files as with Java

• Can persist/read items over network (when available)

• Can use SQLite one db per app


SMS applications should not be overlooked

Cheaper and faster to develop than GUI apps


Available to all handsets for wider usage

Faster to market for specific events

There are wide variety of SMS apps

• Notify customers that meal, prescription, etc is available for collection

• Medical, dentist, etc appointment reminders to prevent no-shows

• Order prescription refills, meals, special offers – Hilton Hotels even do this

• Also use SMS to drive traffic to mobile sites and increase customer sales


http://www.textsmsmarketing.com/sms-text-marketing-case-studies.php

http://www.textsmsmarketing.com/sms-text-marketing-case-studies.php

Also other usual contests, etc

• SMS voting contests

• Send photo to win prizes contests

• Communicate with call centres via SMS

• Query and reserve products via SMS

• Scheduled SMS sending to coordinate with other actions for business and students

• Many more too


http://www.spotlightideas.co.uk/?p=4582

http://www.spotlightideas.co.uk/?p=4582

SMS apps reach many people

• SMS is reliable and can be sent any time

• Supported by ALL mobile phones – can reach about 50% of population, ie 3.3 bn

• Supports reverse billing – thus customer pays for receiving new ringtone, etc that is sent from you to them


http://www.developershome.com/sms/

http://www.developershome.com/sms/

SMS apps can be easy to build

• The components are free to set up and develop

• SMPPsim for simulating SMS center and responses http://www.seleniumsoftware.com/downloads.html

• Use SMPP API for communicating with SMS center http://smppapi.sourceforge.net/

• http://www.kannel.org/ provides an SMS gateway for WAP and SMS apps


Some examples are online

• Developers Home provides details about SMS and low level tutorial http://www.developershome.com/sms/

• O’Reilly have Java tutorial too http://tim.oreilly.com/pub/a/onjava/2004/06/09/sms.html?page=1

• http://www.esendex.co.uk/ provide API to run SMS apps – free developer period


Txteagle outsources work to everyone

• Break work into useful chunks anyone can do via text

• SMS surveys with airtime compensation

• Train workers so know reliability

Bruce Scharlau, University of Aberdeen, 2010http://txteagle.com/

Deconstruct tasks for greater speed and security

Bruce Scharlau, University of Aberdeen, 2010http://txteagle.com/?q=technology

Txteagle changes lives


http://www.youtube.com/watch?v=dBsLAecq6Jw -short version – 6 minutes

http://www.youtube.com/watch?v=Ivz2foChQYU -long version – 40 minutes

http://txteagle.com/?q=workforce/geographies

Documents

Bruce Scharlau, University of Aberdeen, 2010 Android Storage & SMS Apps Mobile Computing Unless otherwise stated, images are from android sdk See Unlocking