How to delete SharedPreferences automatically after one month?

Question

I want to delete SharedPreferences, if they exist, after one month automatically. I could not find any solutions. Is this possible to make?

Thanks a lot.

Answer 1

long installed = context
    .getPackageManager()
    .getPackageInfo(context.getPackag‌​eName(), 0)
    .firstInstallTime
;

public long firstInstallTime The time at which the app was first installed. Units are as per System.currentTimeMillis().

Now you can compare two date and get months diffrent by using GregorianCalendar after you get one month different do as you want..clear sharedPrefrence.edit().clear().commit()

Answer 2

It depends.

The easiest way is to delete it when the user starts the app. When the apps is created, you check the SharedPreferences for the last updated time. If it's null (the first time), you save the current time in milliseconds as a long. If it's not null, you read it and compare it against the current time. If it less than a month, you do nothing. If it's more than a month, you clear the shared preferences and, after clearing it, insert the new time.

Something like:

long lastUpdate = sharedPreferences.getLong(LAST_UPDATE, -1);
if(lastUpdate == -1) {
//First time
sharedPreferences.edit().putLong(LAST_UPDATE, System.currentTimeMillis()).apply();
} else {
boolean isMoreThanAMonth = //Here you should do the math. it depends, you want to consider a month like 30 days, or you want to know if it was in another month... somehthing like that
if(isMoreThanAMonth) {
sharedPreferences.edit().clear().apply()
}
}

Of course, if you want to clear the SharedPreferences even if the user does not open the app you should use a Service. It's more complex and expensive for the OS, so you should try to go for the first one if it fits your requirement.

Answer 3

One possible way,
1. get the calendar instance.
2. Get maximum day of month.
3. Store in a var1 string in format of dd/mm/yyyy.
4. Get the current date from some calendar object and store in same way from point 3 but in var2.
5. Compare two strings.
6. If match then it will be last day of month and call delete() on your files.
Done.