Understanding Android Content Providers
The previous chapter worked through the creation of an example application designed to store data using a SQLite database. When implemented in this way, the data is private to the application and, as such, inaccessible to other applications running on the same device. While this may be the desired behavior for many types of application, situations will inevitably arise whereby the data stored on behalf of an application could be of benefit to other applications.Check the site Filmy god
A prime example of this is the data stored by the built-in Contacts application on an Android device. While the Contacts application is primarily responsible for the management of the user’s address book details, this data is also made accessible to any other applications that might need access to this data. This sharing of data between Android applications is achieved through the implementation of content providers.
What is a Content Provider?
A content provider provides access to structured data between different Android applications. This data is exposed to applications either as tables of data (in much the same way as a SQLite database) or as a handle to a file. This essentially involves the implementation of a client/server arrangement whereby the application seeking access to the data is the client and the content provider is the server, performing actions and returning results on behalf of the client.
A successful content provider implementation involves a number of different elements, each of which will be covered in detail in the remainder of this chapter. 49.2 The Content Provider A content provider is created as a subclass of the android content Content Provider class. Typically, the application responsible for managing the data to be shared will implement a content provider to facilitate the sharing of that data with other applications. The creation of a content provider involves the implementation of a set of methods to manage the data on behalf of other, client applications. These methods are as follows: