Difference Between commit and apply in Android SharedPreferences

java android sharedpreferences
Veer Shrivastav picture Veer Shrivastav · Mar 11, 2013 · Viewed 13.8k times · Source

SharedPreferences are used to save Application data in Android.

commit() and apply() both are used to save the changes in the shared preferences.

As mentioned in Android Library:

public abstarct void apply():

Unlike commit(), which writes its preferences out to persistent storage synchronously, apply() commits its changes to the in-memory SharedPreferences immediately but starts an asynchronous commit to disk and you won't be notified of any failures. If another editor on this SharedPreferences does a regular commit() while a apply() is still outstanding, the commit() will block until all async commits are completed as well as the commit itself.

public abstract boolean commit ():

Commit your preferences changes back from this Editor to the SharedPreferences object it is editing. This atomically performs the requested modifications, replacing whatever is currently in the SharedPreferences.

Does this mean that the changes made by commit() are instant as compared with apply()? Which one is better?

If I need to use the same shared preference value in the next immediate activity, which one should I use? As I have seen if the value of Preference is updated it is not reflected till the application is restarted.

Answer

fedepaol picture fedepaol · Mar 11, 2013

Commit() is instantaneous but performs disk writes. If you are on the ui thread you should call apply() which is asynchronous.

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