DATA PERSISTENCE IN ANDROID OPERATING SYSTEM
- 1. Data persistence in Android CS-6TH E AYESHA JAVED (30) Hira Saeed(46) Hamna Nasir(55) Tehseen Iqbal(06)
- 3. What is Data persistence? • Persistence is "the continuance of an effect after its cause is removed". In the context of storing data in a computer system, this means that the data survives after the process with which it was created has ended. In other words, for a data store to be considered persistent, it must write to non-volatile storage
- 4. WHY Persisting data ? • Persisting data is an important topic in application development, as users typically expect to reuse data in the future. For Android, there are primarily Four basic ways of persisting data: • A lightweight mechanism known as shared preferences to save small chunks of data • Traditional file systems (Internal) • External systems (Flash,drive).. • A relational database management system through the support of SQLite databases
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- 17. Shared preferences internal structure • Shared preferences internally has an in-memory storage on top of disk storage. Every operation goes through in-memory storage first and then to the disk. • In-memory storage is basically a HashMap which allows O(1) runtime complexity for all operations.
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- 26. CHECK THE CODE OF SHARED PREFERENCES CHECK THE CODE OF SHARED PREFERENCES
- 42. Cursor cursor = getContentResolver().query(Uri.parse(queryUri), projection, selectionClause, selectionArgs, sortOrder);
- 44. • <provider android:name=".WordListContentProvider" android:authorities="com.android.example.wordlistsqlwithco ntentprovider.provider" android:exported="true"/>
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- 49. • shared preferences are the location where you can store the secret information for your app, like setting cookies in the browser, this can be used for login credentials and other. • where as content provider stores and retrieves the data and make it available to other applications also. like suppose you want to access the contacts available in the android phone, they can be accessed by content providers CHECK THE CODE OF CONTENT PROVIDER CHECK THE CODE OF CONTENT PROVIDER
Editor's Notes
- #8: Store private and primitive data in key value pairs Primitive types are the most basic data types available within the Java language. There are 8: boolean , byte , char , short , int , long , float and double . These types serve as the building blocks of data manipulation in Java
- #13: android.content.SharedPreferences.Editor Interface used for modifying values in a SharedPreferences object. All changes you make in an editor are batched, and not copied back to the original SharedPreferences until you call commit() or apply()
- #18: HashMap is a Map based collection class that is used for storing Key & value pairs, it is denoted as HashMap&lt;Key, Value&gt; or HashMap&lt;K, V&gt;.
- #45: android:exported Whether the content provider is available for other applications to use:true: The provider is available to other applications. Any application can use the provider&apos;s content URI to access it, subject to the permissions specified for the provider. false: The provider is not available to other applications. Set android:exported=&quot;false&quot;to limit access to the provider to your applications. Only applications that have the same user ID (UID) as the provider will have access to it.
- #63: In revision control systems, a repository[1] is a data structure which stores metadata for a set of files or directory structure In computing, cross-platform software (also multi-platform software or platform-independent software) is computer software that is implemented on multiple computing platforms.[
- #71: The main purpose CardView serves in the Material Design universe is to provide a unified look to all of the card based UIs making it easier for developers to create seamless interfaces. In this post, we will see what opportunities CardView provides on Android platform and how to use it properly in our application