java - 用 Java 编写和比较日期

Question

我用它来创建一个日期并将其放入数据库中:

String currentDateTimeString = DateFormat.getDateInstance().format(new Date());

我想构建一个与上面格式类似的日期，并将其与 currentDateTimeString 进行比较。

我有 3 个整数。我该如何做到这一点(整数年，整数月，整数日)？

更新:

Calendar cal = Calendar.getInstance();

         cal.set(Calendar.MONTH, month);
         cal.set(Calendar.YEAR, year);
         cal.set(Calendar.DAY_OF_MONTH, day);

         Date result = cal.getTime();
         String currentDateTimeString2 = DateFormat.getDateInstance().format(result);

我在这里做错了..两者不相等: currentDateTimeString2==currentDateTimeString//false

Answer 1

Calendar cal = Calendar.getInstance();
cal.set(Calendar.DATE, date);
cal.set(Calendar.MONTH, month-1);//it starts from 0
cal.set(Calendar.YEAR, year);
cal.set(Calendar.HOUR, 0);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);
Date result = cal.getTime();

I do here something wrong..both arent equal: currentDateTimeString2==currentDateTimeString //false

字符串是对象，不能使用equals()方法与==进行比较