Content providers, appdata and files

Question 1

What are the resources for app data and content providers?

Answer 1

Resources include:
- https://developer.android.com/guide/topics/data
- https://developer.android.com/guide/topics/providers/content-providers

References: Meier, Ch. 9; Smyth, Ch. 67, 68

Question 2

What types of data storage options does Android provide?

Answer 2

The system provides several options for saving app data:
- App-specific storage
- Shared storage
- Preferences
- Databases

Question 3

What factors should you consider when choosing a data storage solution?

Answer 3

Consider the following requirements:
- Space required for data
- Reliability of data access
- Type of data to store
- Privacy of data to your app

Question 4

What are the two types of physical storage locations in Android?

Answer 4

Android provides:
- Internal storage: smaller, available on all devices
- External storage: requires permissions for access

Question 5

What are the permissions for accessing external storage?

Answer 5

Permissions include:
- READ_EXTERNAL_STORAGE
- WRITE_EXTERNAL_STORAGE
- MANAGE_EXTERNAL_STORAGE (Android 11)

Question 6

What locations does the system provide for storing app-specific files?

Answer 6

The system provides:
- Internal storage directories
- External storage directories

Access details: https://developer.android.com/training/data-storage/app-specific

Question 7

What is a Content Provider in Android?

Answer 7

A Content Provider is an Android component that manages access to data, controls permissions, and provides an abstraction for data storage.

Question 8

What types of data do Android content providers manage?

Answer 8

Content providers manage:
- Audio
- Video
- Images
- Personal contact information

Question 9

What functions does a Content Provider serve?

Answer 9

A Content Provider coordinates access to data storage for:
- Sharing data with other applications
- Sending data to widgets
- Synchronizing application data

Question 10

How is data represented in a Content Provider?

Answer 10

Data is presented as tables where:
- Rows represent instances of data
- Columns represent individual pieces of data

Question 11

How do you access a Content Provider from the UI?

Answer 11

Use CursorLoader to run asynchronous queries in the background and request permissions in the manifest file.

Question 12

What steps are involved in creating a Content Provider?

Answer 12

Steps include:
- Designing raw storage
- Defining a concrete implementation of ContentProvider
- Defining authority string and content URIs

Question 13

What are the abstract methods of the ContentProvider class?

Answer 13

Abstract methods include:
- query()
- insert()
- update()
- delete()
- getType()
- onCreate()

Question 14

What is the purpose of Loaders in Android?

Answer 14

Loaders help asynchronously load data for Activities or Fragments and can monitor data sources for changes.

Question 15

What is required to use a Loader?

Answer 15

To use a Loader, initialize it with LoaderManager and implement LoaderManager.LoaderCallbacks.

Question 16

Where can you find more information about Content Providers?

Answer 16

More info can be found at: https://developer.android.com/guide/topics/providers/content-provider-basics

Question 17

How can you interact with a Content Provider via adb?

Answer 17

You can use adb shell commands to query a Content Provider. Example:
$ adb shell content query –uri ‘content://com.ebookfrenzy.sqldemo.provider.MyContentProvider/customers/1’ –where ‘customerphone=5’