Java 日期比較

1.日期轉String

  Date轉String

    Date d=new Date();

    SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

    String ds=df.format(d);

2.String轉Date

    String ds=new String("2019-06-09 10:12:32"); 

    Date sd=df.parse(ds);

3.使用compare方法比較

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        String beginTime=new String("2017-06-09 10:22:22");
        String endTime = new String("2020-06-09 10:22:22");
        Date nowTime = new Date();
        String now = format.format(nowTime);
        System.out.println(now);
        System.out.println("返回正數，代表now > beginTime,左側參數 > 右側參數");
        System.out.println(now.compareTo(beginTime));
        System.out.println("返回0，代表now > beginTime,左側參數 = 右側參數");
        System.out.println(now.compareTo(now));
        System.out.println("返回負數，代表now < beginTime,左側參數 < 右側參數");
        System.out.println(now.compareTo(endTime));

4.結果