Content Providers

A content provider is one of the basic Android app components that manages data access from a repository. We can use content providers to provide data access and facilitate data sharing between the repository and various apps. Content providers can also provide a UI for working with the data. We can either create a new content provider in our app to share data with other apps or we can access an existing content provider in a different app. Let’s explore content providers.

Client-server mechanism

Android apps and their components can share data across different processes using a client-server mechanism. Android implements a content provider as a server, which can receive requests from multiple clients and respond to those requests. When a client app component has to access data from a content provider, it sends a request to the content provider server. The server processes the request and sends a response back to the client. The Android OS handles the communication between the client and the server.

The apps access the content provider using a provider client object; both offer a standard interface to secure data access and perform IPC.

The basic steps of how this client-server mechanism works are as follows:

1. The client interacts with a content provider by utilizing the ContentResolver class. It sends requests to the content provider by invoking methods such as query() and provides a URI object that specifies the data to be accessed. Android uses URIs to identify specific data within a content provider, such as a row in a database table.

2. The content provider processes the request by using the URI object. It performs the requested operation, such as querying or updating the data, and sends a response back to the client. For instance, the client receives a Cursor object containing the results of the query when it calls the query() method. ... ...