Calculating months elapsed since a given date

Question

I am using traceview and DDMS to analyse my operation. The following is my traceview as displayed in DDMS:

According to the above, the LoaderClass.months() function takes about 51% of the CPU time and 798.80 System time. I have reproduced this function below:

public int months(String date) {

        SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd");
        Date d1 = null;
        try {
            d1 = f.parse(date);
        } catch (ParseException e) {

            e.printStackTrace();
        }
        Date d2 = new Date();  
        Calendar c1 = Calendar.getInstance();
        c1.setTime(d1);
        Calendar c2 = Calendar.getInstance();
        c2.setTime(d2);
        int diff = 0;
        if (c2.after(c1)) {
            while (c2.after(c1)) {
                c1.add(Calendar.MONTH, 1);
                if (c2.after(c1)) {
                    diff++;
                }
            }
        } else if (c2.before(c1)) {
            while (c2.before(c1)) {
                c1.add(Calendar.MONTH, -1);
                if (c1.before(c2)) {
                    diff--;
                }
            }
        }
        return diff;
    }

Below is a more detailed view of the method as on DDMS:

Answer 1

Don't reinvent the wheel for what Joda time has already written for you:

int monthsBetween = Months.monthsBetween(new LocalDate(date1), new LocalDate()).getMonths();

From the localDate doc:

1. You can pass a string in the constructor. (you could test that)
2. Empty constructor is current time.

Answer 2

I don't like the naming style you're using. Single and double-letter identifiers are annoying.

Use meaningful names!

Isn't this:

SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd");

More enjoyable to read like that?

SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-MM-dd");

Also, it's not immediately apparent what the method does - months looks more like a variable name than a method, because it doesn't start with a verb.

A more meaningful name could perhaps be getElapsedMonths... and then the xx2 variables could be named xxPresent, and xx1 could be xxSpecified, so getElapsedMonths would calculate the number of months elapsed since a specified date.