问使用Thread.sleep()提高效率

EN

public static void main(String args[])
{
    initUI();
    try
    {
        while(true)
        {
            Thread.currentThread().sleep(1000);
            getTime();
        }
    } catch(Exception e){System.out.println("An error has occured...");}
}

public static void getTime()
{
    Calendar c = Calendar.getInstance();
    // Gets abstract current time in ms
    long now = c.getTimeInMillis();

    c.set(Calendar.HOUR_OF_DAY, 0);
    c.set(Calendar.MINUTE, 0);
    c.set(Calendar.SECOND, 0);
    c.set(Calendar.MILLISECOND, 0);

    // Gets current time in ms
    long msPassed = now - c.getTimeInMillis();
    // There are 86,400,000 milliseconds in a day
    // Gets the seconds remaining in the day
    long secRemaining = (86400000 - msPassed) / 1000;

    //-----------------------------------------------------// 
    // Creates a new calendar for today
    Calendar cal = Calendar.getInstance();
    int currentDayOfYear = cal.get(Calendar.DAY_OF_YEAR);

    // Creates a calendar for November 20th, 2016
    Calendar aniv = new GregorianCalendar(2016,10,20);
    aniv.set(Calendar.MONTH, 10);
    aniv.set(Calendar.DAY_OF_MONTH, 20);
    int aniversary = aniv.get(Calendar.DAY_OF_YEAR);

    remaining = ((aniversary - currentDayOfYear) * 24 * 60 * 60) + secRemaining;
    setTextOnScreen(remaining);
}

public static void setTextOnScreen(long num)
{
    text.setForeground(Color.GREEN);
    text.setLocation((int)width/2 - 150, 50);
    text.setFont(new Font("Monospaced", Font.BOLD, 48));
    text.setSize(300,150);

    text.setText("" + num);
    panel.add(text);
}