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This article mainly introduces the relevant knowledge of "how to realize the access mechanism of data storage in Android". The editor shows you the operation process through an actual case. The operation method is simple, fast and practical. I hope this article "how to implement the access mechanism of data storage in Android" can help you solve the problem.

1. How to make the application's data accessible externally?

The answer is to use the content provider interface of android, content provider can expose the private data of the application to other application.

There are two options to expose application data, one is to create your own content provider, and the other is to use the existing content provider provided that the data type is consistent.

2. Data type of Android data store

Android provides a series of content type. Including image, audio, and video files and personal contact information and so on.

3. Android data storage mechanism

Android provides the following mechanisms for storing and fetching data

3.1. Preference

Preference provides a lightweight access mechanism, mainly through the keyword to read and store a Preference value.

For example, when the load system starts, it gets the value saved the last time the system exited.

View plaincopy to clipboardprint?. . . Public static final String PREFS_NAME = "MyPrefsFile";. . . @ Override protected void onCreate (Bundle state) {super.onCreate (state);. . . / / Restore preferences SharedPreferences settings = getSharedPreferences (PREFS_NAME, 0); boolean silent = settings.getBoolean ("silentMode", false); setSilent (silent);} @ Override protected void onStop () {super.onStop (); / / Save user preferences. We need an Editor object to / / make changes. All objects are from android.context.Context SharedPreferences settings = getSharedPreferences (PREFS_NAME, 0); SharedPreferences.Editor editor = settings.edit (); editor.putBoolean ("silentMode", mSilentMode); / / Don't forget to commit your editsthanks! Editor.commit ()}. . . Public static final String PREFS_NAME = "MyPrefsFile";. . . @ Override protected void onCreate (Bundle state) {super.onCreate (state);. . . / / Restore preferences SharedPreferences settings = getSharedPreferences (PREFS_NAME, 0); boolean silent = settings.getBoolean ("silentMode", false); setSilent (silent);} @ Override protected void onStop () {super.onStop (); / / Save user preferences. We need an Editor object to / / make changes. All objects are from android.context.Context SharedPreferences settings = getSharedPreferences (PREFS_NAME, 0); SharedPreferences.Editor editor = settings.edit (); editor.putBoolean ("silentMode", mSilentMode); / / Don't forget to commit your editsthanks! Editor.commit ();}

3.2. Files

Through the File mechanism in Android data storage, you can directly store a file to your phone's file system path such as an SD card.

It should be noted that files stored by default cannot be accessed by other application!

Context.openFileInput () returns the standard file input object for java.

Context.openFileOutput () returns the standard file output object for java.

3.3. Databases.

Android uses the SQLite database.

You can call SQLiteDatabase.create () and and the subclass SQLiteOpenHelper.

Android also provides sqlite3 database tool, which you can use to directly access and modify the database like MySQL tool.

3.4. Network.

* you can also store data over the network, using the java class of the following two packages.

This is the end of java.net.* android.net.* 's introduction on "how to implement the access mechanism of data storage in Android". Thank you for reading. If you want to know more about the industry, you can follow the industry information channel. The editor will update different knowledge points for you every day.

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