java – How to change values in the shared preference-ThrowExceptions

Exception or error:

I’ve created an application which uses a shared preference in order for the user to login. The password of the user is saved in the preference. My problem is, how can I change the password in the preference if the user wants to change his/her password?

How to solve:
SharedPreferences prefs = ... // you already know how to use prefs and have one of this objects
Editor editor = prefs.edit();
editor.putString("password", "new value");
editor.apply();

###

Use apply() instead of commit()

It is recommended that you use Editor.apply() instead of commit() because apply() works asynchronously in the background therefore it is less likely that there will be ANR because of that(if at all).

getSharedPreferences("FILE_NAME", 0 /*FILE_MODE*/)
     .edit()
     .putString("password", "new value")
     .apply();

Docs mention about apply(),

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.

Note that when two editors are modifying preferences at the same time,
the last one to call apply wins.

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.

As SharedPreferences instances are singletons within a process, it’s
safe to replace any instance of commit() with apply() if you were
already ignoring the return value.

You don’t need to worry about Android component lifecycles and their
interaction with apply() writing to disk. The framework makes sure
in-flight disk writes from apply() complete before switching states.

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