Java Date difference in terms of days [duplicate]

Question

Could anyone please help me out for calculating Date difference in terms of no of days in an efficient way?

Date nextCollectionDate = dispenseNormal.getDispensing().getNextCollectionDate();
Date currentDate = new Date();
int daysDiff = currentDate - nextCollectionDate;

Answer 1

//diff in msec
long diff = currentDate.getTime() - nextCollectionDate.getTime();

//diff in days
long days = diff / (24 * 60 * 60 * 1000);