How to calculate “time ago” in Java?

In Ruby on Rails, there is a feature that allows you to take any Date and print out how “long ago” it was.

For example:

8 minutes ago
8 hours ago
8 days ago
8 months ago
8 years ago

Is there an easy way to do this in Java?

Answer

Take a look at the PrettyTime library.

It’s quite simple to use:

import org.ocpsoft.prettytime.PrettyTime;

PrettyTime p = new PrettyTime();
System.out.println(p.format(new Date()));
// prints "moments ago"

You can also pass in a locale for internationalized messages:

PrettyTime p = new PrettyTime(new Locale("fr"));
System.out.println(p.format(new Date()));
// prints "à l'instant"

As noted in the comments, Android has this functionality built into the android.text.format.DateUtils class.