Data类

示例代码：

public class Demo3 {
    public static void main(String[] args) {
       //创建一个Date类对象
        Date date1 = new Date();
        System.out.println(date1.toString()); //当前时间
        Date date2 = new Date(date1.getTime()-(60*60*24*1000));
        System.out.println(date2);   //昨天这个时候
        //方法  after ,  before
        boolean after = date1.after(date2);//date1是否在date2之后
        System.out.println(after);   //true
        boolean before = date1.before(date2);  //date1是否在date2之前
        System.out.println(before);  //false

        //比较 compareTo();
        int i = date1.compareTo(date2);
        System.out.println(i);  //1
        int i1 = date2.compareTo(date1);
        System.out.println(i1);  //-1

        //比较是否相等  equals();
        boolean equals = date1.equals(date2);
        System.out.println(equals);
    }
}