SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");
Date date =new Date();
//你的出生年月日
String Dbirth=sdf.format("");
try {
Date d1 = sdf.parse(dt);
Date d2 = sdf.parse(Dbirth);
long diff = d1.getTime() - d2.getTime();
long days = diff / (1000 * 60 * 60 * 24);
} catch (ParseException e) {
e.printStackTrace();
}