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How to delete SharedPreferences automatically after one month?

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.

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.

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()

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.

How to display different text in a textview according to date in android app?

I am very new at coding and want to develop an android app that display new content according the day you are opening the app.
For example : 20 days to eat better
Day 1 (user open the app), then the message is "XXXXXX"
Day 2 (user open the app), the the message is "YYYYY"
Day 1 is a the day the user download the app.
I understood that I need to use "timestamp" as a string, but how can I do it ?
Thanks for your help !

I'm not quite sure about what you are trying to achieve. But based on what I understood. You just want to get the current day
Calendar calendar = Calendar.getInstance();// sets the current date
calendar.get(Calendar.DATE);// gets the current day returns an integer value
calendar.getTime();// gets the current date and returns a Date Object
You can start from here. The calendar class offers you different values for the current calendar date. I'm pretty sure all you need to know is available if you just tried to search the web. But to give you something to work on, experiment with the Calendar class for date manipulations.
EDIT:
If you want to display a certain string based on the date/day. What you can do is to create an array and user the date/day value to get the string.
String[] stringArray = {"Text1", "Text2", "Text3", "Text4", "Text5", "Text6", "Text7"};
String theStringYouWant = stringArray[calendar.get(Calendar.DATE)];
You can use this approach if you have short strings and limited record. But if you have tons of data, you might want to utilize a database to store your data, and use this approach.

comparing input Date & Time with current date & time in android

I am creating a "To-do Things" app where a user can create tasks to be done. In the Main activity I have a fragment which consists of three EditTexts ie Notification Content , Date & Time of notification.
Each new entry is added to a database. This database is displayed in form of ListView in another activity.
My Questions are-:
Q1) I want to compare date & time of each entry & print only those which are about to come ie whose date & time is after the present date & time.So how should I perform the comparison?
Q2) When the date & time is reached generate a notification .

Q1) Use the Calendar class. You can take a Calendar object and set its date and time with your user data (using Calendar.set) and then compare with another calendar which you set to the current time as follows:
Calendar cal = GregorianCalendar.getInstance();
cal.setTimeInMillis(System.currentTimeMillis());
To compare two calendars you can use the Calendar.before method, or you can convert them back into "timeInMillis" and calculate the difference in milliseconds.
Q2) Use theAlarmManager and a BroadCastReceiver

How to store current locale date and time in SQLite

..and later retrieve and show them as Strings?
I'm asking the user some input and I want to store both the date (i.e., day, month and year) and the time (i.e., the hour of the day) this input was submitted. Each submission is then saved in my SQlite database, and later retrieved from a RecyclerView.
I'm facing two problems at least. Right now I set up two TEXT fields in the database, FIELD_DATE and FIELD_TIME, where I'd like to store the string representation of date & time, in a format depending on the Android user locale.
From what I've read, the android.text.format.DateFormat should help me. So I set:
java.text.DateFormat dateFormat = DateFormat.getMediumDateFormat(getActivity());
java.text.DateFormat timeFormat = DateFormat.getTimeFormat(getActivity());
Now I think I should call format(Date d) on both objects to get my string, but I don't know where do I get this Date object - don't even know if my two lines are correct. So:
How to get a string representation of current date & time, based on the user defined (at OS level) locale?
That said (asked), I wonder if two fields for date & time are really what I'm looking for. As said, at the end I would like to show a RecyclerView reading the database. In that I will also need to filter out entries based on date, i.e.
Entries referring to last week // last month // All
entries
So I'm also asking:
Is a two-text-fields pattern the right choice to store date & time, given the need to easily filter out entries belonging to, say, last week? Should I better have separate columns for day, month and year?
How to query the database to have only last week rows, given the FIELD_DATE / FIELD_TIME structure (or any other better structure you can suggest)?
I'm quite stuck on these three questions.
Edit: finally came up with how to get the strings I wanted at first, it was as simple as instantiating a new Date object:
Date d = new Date();
String date = DateFormat.getMediumDateFormat(getActivity()).format(d);
String time = DateFormat.getTimeFormat(getActivity()).format(d);
Now I have both the needs to display these strings (which is quite simple, as they are already formatted) and to apply some filter to the db, like entries belonging to last week (which, in turn, would be quite simple with current time in millis since 1970). What to do?

If you want to be able to run complex queries such as find all records from last week, I would recommend storing a timestamp in an integer instead. A timestamp is expressed as the number of milliseconds since the Epoch (Jan 1, 1970). It makes it easy to make queries on exact date and time ranges.
The timestamp is easily found from e.g. System.currentTimeMillis().
The other approach would be to use sqlite's built in date type, but I would personally choose the timestamp approach.
Is there any reason you would want to store it in the current locale's format in the first place? If you are displaying the date to the user you're likely better of formatting the timestamp into a date when displayed, using one of the many date features of Java and android such as java.util.Calendar, java.util.Date, android.text.SimpleDateFormat etc.
As an example, you could run this code to get the timestamp of the start of this month:
Calendar now = Calendar.getInstance();
now.set(Calendar.DAY_OF_MONTH, 1);
now.set(Calendar.HOUR_OF_DAY, 0);
now.set(Calendar.MINUTE, 0);
now.set(Calendar.SECOND, 0);
long startOfThisMonth = now.getTimeInMillis();

Using a DatePicker in Android dev: How do I compare the date picked to today's date?

I'm really stuck with a certain problem and I'm hoping someone can help me understand the problem and come to a solution. I've looked online a fair bit but can't see an answer unless it's been staring me in the face :-/
Basically, I'm creating a very basic TV Guide app. It parses data from an RSS feed which has days offset (yesterday was -1. today is 0, tomorrow is 1, etc etc) and I'm trying to implement a DatePicker that allows the user to see what is on a particular channel when they select yesterday, today, tomorrow, etc.. but if they pick a date that is out-with the range (at the moment it's a week in advance), a simple Toast message will be displayed.
My questions I guess are, firstly, how do I use maybe an IF ELSE to either parse the specific channel data for the day the user wants or display an error Toast message, and, how do I go about converting the days from what the user has put in compared to the actual date today into integers? If they select yesterday's date it will go to URL "http://example.com/-1/channel", if they select tomorrow's date it will go to URL "http://example.com/1/channel" etc etc etc.
Code is available if anyone needs to see it, but I think if someone would be kind enough to explain the logic, I'd like to see if I can come to the answer myself...
Thanks a lot folks!!

You should use a DatePicker to allow the user to choose the when.
Time in Android is stored on a long (not an int). And the long time can easily be converted back and forth between long (always milli-seconds) and a Date object.
The Date object gives you all sorts of tools to compare before and after, look at months, minutes, hours, etc.
The current time is determined by:
long nowMs = System.currentTimeMillis();
int nowSec = (int)(nowMs / 1000);
There is also a very important Calendar object. This allows you to parse textual date formats as delivered by your http functions in and out of various dates.
For example:
Calendar cal = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd hh:mm:ss Z");
String text = sdf.format(cal.getTime();
You will have to put all these tools together with a DatePicker example such as the one here Create a DatePicker to complete your TV Guide application.
Reference:
Date
Calendar
DatePicker

EDIT : Check David's Answer its better.
First Filter the date selected with today's date. You can compare it by date.isbefore(date) or date.isafter(date) these booleans will let you tell know if a date is of past or future or present. then to further calculate the days inbetween you can make a method with switch statement that will basically convert the selected date and the current date into miliseconds(Date.getTimeinmiliseconds)
if the date is of past take the difference of present time in miliseconds and past date in miliseconds. If the date is of future do the opposite. Take the difference and convert it to days difference with appropriate sign(negative/positive).
Please refer this link for a better coding example