Try this:
import java.text.SimpleDateFormat;
import java.util.Date;
public class Main {
public static void main(String [] args) throws Exception {
SimpleDateFormat displayFormat = new SimpleDateFormat("HH:mm");
SimpleDateFormat parseFormat = new SimpleDateFormat("hh:mm a");
Date date = parseFormat.parse("10:30 PM");
System.out.println(parseFormat.format(date) + " = " + displayFormat.format(date));
}
}
which produces:
10:30 PM = 22:30
See: http://download.oracle.com/javase/1.5.0/docs/api/java/text/SimpleDateFormat.html