Use the following code :
new Timer(""){{
    // code to time 
}}.timeMe();
public class Timer {
    private final String timerName;
    private long started;
    public Timer(String timerName) {
        this.timerName = timerName;
        this.started = System.currentTimeMillis();
    }
    public void timeMe() {
        System.out.println(
        String.format("Execution of '%s' takes %dms.", 
                timerName, 
                started-System.currentTimeMillis()));
    }
}