Question

I am working on an android app at school. I am currently building a notepad. I would like to know if there are any ways to get the date and store it into the sqlite database as a date format and then, when I am retrieving it from the database and write it into my textview, I could display hh::mm if the note was written/modified today, or dd/mm/yy if it were (let’s say) written yesterday. To be more clear:

1. I write a note
2. I get the date
3. I insert everything into my database table
4. Retrieve the data into a ListView
5. for each note, I want to display the date in the right format,( if the date was the same day, just display the hh:mm, yesterday if it was written yesterday, else display dd/mm/yy

Also, which way is better to store the date into database, as Date format? I searched online and it appears that there are several ways to do it, which one is the best?

Answer 1

Date can be converted to long value (number of milliseconds passed from Jan, 1 1970 00:00:00 UTC+0000).

It surely is the most convenient presentation of date:

1. System.currentTimeMillis() returns current date in this format;
2. This format is used to set an alarm using AlarmManager;
3. Easy to determine which date is earlier (just compare two long values – less is earlier);
4. Easy to store in the database or using SharedPreferences.

Calendar class which is standard for date operations in Java, also supports this format – it has setTimeInMillis() and getTimeInMillis() functions.

For more details, refer to the documentation on Calendar class.

As for different date formats, check out the SimpleDateFormat class.