preferences - Can SharedPreferences be shared among different Android applications?

Question

As I checked in APIs description for getSharedPreferences(String, int),Second attribute is defining accessibility mode and can take 0 or MODE_PRIVATE for the default operation, MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE to control permissions.

But there is this small note in API description:

Note: currently this class (android.content.SharedPreferences) does not support use across multiple processes. This will be added later.

Moreover in Mark L. Murphy book "beginning Android 2" he mentioned:

(Eventually, preferences might be shareable across applications, but that is not supported as of the time of this writing)

Im so confused! does this mean that MODE_WORLD_READABLE and MODE_WORLD_WRITEABLE of getSharedPrefrences is there but NOT SUPPORTED YET in latest API level???

Thanks! Migan

Answer 1

My book reference is based upon that comment.

Moreover, making any file MODE_WORLD_READABLE or (worse) MODE_WORLD_WRITEABLE is a bad idea. You lose any hope of security.

If you wish to share data between two applications, there are a myriad of solutions, such as:

• service with an API exposed by AIDL
• service with an API exposed via commands sent via startService() and responses sent via a Messenger or createPendingResult() PendingIntent or something
• content provider
• broadcast Intents

All of those allow you to define permissions for integration and let you control the granularity of access.