What does @hide mean in the Android source code?

by

Android has two types of APIs that are not accessible via SDK.

The first one is located in package com.android.internal. The second API type is a collection of classes and methods that are marked with the @hide Javadoc attribute.

Starting from Android 9 (API level 28), Google introduces new restrictions on the use of non-SDK interfaces, whether directly, via reflection, or via JNI. These restrictions are applied whenever an app references a non-SDK interface or attempts to obtain its handle using reflection or JNI.

But before API level 28, the hidden methods could still be accessed via Java reflection. The @hide attribute is just part of Javadoc (droiddoc also), so the @hide just simply means the method/class/field is excluded from the API docs.

For example, the checkUidPermission() method in ActivityManager.java uses @hide:

/** @hide */
public static int checkUidPermission(String permission, int uid) {
    try {
        return AppGlobals.getPackageManager()
                .checkUidPermission(permission, uid);
    } catch (RemoteException e) {
        // Should never happen, but if it does... deny!
        Slog.e(TAG, "PackageManager is dead?!?", e);
    }
    return PackageManager.PERMISSION_DENIED;
}

However, we can call it by reflection: 

Class c;
c = Class.forName("android.app.ActivityManager");
Method m = c.getMethod("checkUidPermission", new Class[] {String.class, int.class});
Object o = m.invoke(null, new Object[]{"android.permission.READ_CONTACTS", 10010});

More Related Contents:

  1. How to change the activity background from fragment inside it [closed]
  2. How to have Android Service communicate with Activity
  3. How to restart Activity in Android
  4. How do I programmatically “restart” an Android app?
  5. How to pass data from 2nd activity to 1st activity when pressed back? – android
  6. Clear the entire history stack and start a new activity on Android
  7. Same Navigation Drawer in different Activities
  8. requestFeature() must be called before adding content
  9. Sharing data between fragments using new architecture component ViewModel
  10. How to pass drawable between activities
  11. Launch Android application without main Activity and start Service on launching application
  12. What is the difference between Activity and Context?
  13. How do I maintain the Immersive Mode in Dialogs?
  14. How to provide animation when calling another activity in Android?
  15. Android, how to not destroy the activity when I rotate the device?
  16. When a Fragment is replaced and put in the back stack (or removed) does it stay in memory?
  17. How to listen for preference changes within a PreferenceFragment?
  18. How to finish Activity when starting other activity in Android?
  19. Android: is using setContentView multiple times bad while changing layouts?
  20. Errors managing the UnityPlayer lifecycle in a native android application
  21. Communication between BroadcastReceiver and Activity – android
  22. Coordinator Layout with Toolbar in Fragments or Activity
  23. Alternative to “FLAG_BLUR_BEHIND” in Android?
  24. Start Activity screen even if screen is locked in Android
  25. OnCreateView called multiple times / Working with ActionBar and Fragments
  26. Can i automatically send SMS (Without the user need to approve)
  27. Android: startActivityForResult & setResult for a view class and an activity class
  28. How to have activity in Android with a close button at the top corner?
  29. What method is being called when I close an app
  30. Can you have two activities running at the same time?

Leave a Comment