Everyone,I was looking at android source.But I could not find something valuable for me.Actually,I want to know whether ContentProvider is worked like AIDL.You know ,AIDL can achieve the communication between two independence application.
So, I just want to see how does the ContentProvider work internally.
From ContentProvider Source code
Content providers are one of the primary building blocks of Android
applications, providing content to applications. They encapsulate data
and provide it to applications through the single ContentResolver
interface. A content provider is only required if you need to share
data between multiple applications. For example, the contacts data is
used by multiple applications and must be stored in a content
provider. If you don't need to share data amongst multiple
applications you can use a database directly via
android.database.sqlite.SQLiteDatabase.
According to this and to the information in the link I sent you, ContentProvider isn't using AIDL... It is using the ContentResolver interface.
Content Providers use IPC Binders internally. "In fact, Intents and ContentProvider are just a higher-level abstraction of Binder"
Related
I am about to create two applications which have the same SQLite database. I went through this link. But it does not make sense. I have to update the database from both applications. Please suggest one or more better ways.
You should read about Content Provider
Content providers are one of the primary building blocks of Android
applications, providing content to applications. They encapsulate data
and provide it to applications through the single ContentResolver
interface. A content provider is only required if you need to share
data between multiple applications. For example, the contacts data is
used by multiple applications and must be stored in a content
provider. If you don't need to share data amongst multiple
applications you can use a database directly via SQLiteDatabase.
https://developer.android.com/guide/topics/providers/content-providers
https://developer.android.com/reference/android/content/ContentProvider
Content Provider is a great way to share database with other applications.
When you create a Content Provider, you can define which part of your database can be shared as well.
A Content Provider has following parts-
1. A class that extends ContentProvider class
2. An Authority that distinguishes this ContentProvider from others on the Android O.S.
3. A Contract class that holds Uri to tables and columns that you want to share with other applications
4. A ContentResolver to access data from a ContentProvider
5. Set of user defined permissions to write to and read from a shared ContentProvider. Permissions allow only those apps that you authorize to access your ContentProvider
Here is a simple tutorial about the use of ContentProvider and how to share your database with other applications- https://www.tutorialspoint.com/android/android_content_providers.htm
i'm beginner in android development, need help regarding ContentProvider.
public class My Application extends ContentProvider {}
A ContentProvider manages access to a structured set of data. It encapsulates the data and provide mechanisms for defining data security. ContentProvider is the standard interface that connects data in one process with code running in another process.
Kindly refer following links,
https://developer.android.com/guide/topics/providers/content-provider-creating.html
and
https://www.tutorialspoint.com/android/android_content_providers.htm
A content provider component supplies data from one application to others on request. one application cannot directly access (read/write) other application's data. Every application has its own id data directory and own protected memory area.
Content provider is the best way to share data across applications. Content provider is a set of data wrapped up in a custom API to read and write. Applications/Processes have to register themselves as a provider of data.
In simple language you can say content provider is a shared database which expose his properties and on there behalf of them other application can access and store the data as per the implementation privilege
Content providers can help an application manage access to data stored by itself, stored by other apps, and provide a way to share data with other apps. They encapsulate the data, and provide mechanisms for defining data security. Content providers are the standard interface that connects data in one process with code running in another process. Implementing a content provider has many advantages. Most importantly you can configure a content provider to allow other applications to securely access and modify your app data.
It is not that they are used only to share data with other applications. You may still use them because they provide a nice abstraction, but you don’t have to necessarily share data with other apps. This abstraction allows you to make modifications to your application data storage implementation without affecting other existing applications that rely on access to your data
You can get more info from the documentation.
ContentProvider is mainly used for access data from one application to another application.
For example by using ContentProvider we can get phone contacts,call log from phone to our own application in android.we can also access data which are stored in (sqlite)databases.
I want to share data between different Android applications. On iOS applications I use the Keychain with an accessGroup property so the data is only accessible from my applications plus the data remains even if I delete all applications.
What mechanism can I use to do the same on Android?
Thanks in advance,
You can use ContentProviders. Here is a good tutorial on ContentProviders. And this post specifically tells about data sharing using it.
ContentProviders are the way to go on Android for sharing data between apps.
From the Android tutorials:
Content providers manage access to a structured set of data. They encapsulate the data, and provide mechanisms for defining data security. Content providers are the standard interface that connects data in one process with code running in another process.
Use ContentProviders to do that.
What's the purpose of Content Provider? The document here said:
Content providers store and retrieve data and make it accessible to all applications.
I just want to store my data into Sqlite, no need to share with other application, shall I still need to use Content Provider API?
Sqlite is an Android wrapper for using SQLite DB's. It provides neat and cleaner interface for all DB operations. Ofcourse one of the major pros for using Content providers is it provides mechanism for sharing your data with other apps.
But surely even for storing and retrieving data in db, Content provider provides a nice interface and it is highly recommended.
There are other classes like SqliteDBHelper using which you can perform direct operations on DB.
I am writing a small featurecontrol-application, which has several feature settings stored and managed. All applications use my featurecontrol-application to retrieve settings like whether feature-x is enabled or not or what is feature-x-value . Can I use contentprovider for this or are there any other alternatives?
If you have several applications, and they have to share same data (content) usage of ContentProvider looks to me as quite good and logical solution.
Content provider is one option to implement communication between different applications. But it does not need DB as a backbone. Instead of DB you can use table of constants. To create ContentProvider you just need to override several functions, no constraint is imposed to use DB.
Another option is to implement IPC via AIDL. That also gives you interface to share objects, but IMO since you just need to share constants ContentProvider is easier and faster solution.