java编程，计算相隔天数

public static Date getDate(String time){
Date date=null;
try {
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
date = df.parse(time);
} catch (ParseException e) {
e.printStackTrace();
}
return date;
}

public static void main(String[] args)
{ Date d=new Date();
SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
String dd=df.format(d);
System.out.println(dd);
Date c1 = getDate("2011-11-25");//
Date c2 = getDate("2018-12-26"); //
double timeLong=c2.getTime()-c1.getTime();
int dayNum=(int)(((timeLong/1000)/3600)/24);
System.out.println("你u25351 定u30340 两u20010 时u-27148 点u20043 间u30340 天u25968 是u-230 "+dayNum);
}