一、Calendar操作时间
Date date = new Date();//当前时间
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");//格式化模板
Calendar calendar1 = Calendar.getInstance();
calendar1.setTime(date);
calendar1.add(Calendar.DAY_OF_MONTH,-1);//减一天
System.out.println(sdf.format(calendar1.getTime()));
Calendar calendar2 = Calendar.getInstance();
calendar2.add(Calendar.MONTH,-1);//减一月
System.out.println(sdf.format(calendar2.getTime()));
Calendar calendar3 = Calendar.getInstance();
calendar3.add(Calendar.YEAR,-1);//减一年
System.out.println(sdf.format(calendar3.getTime()));
Calendar calendar4 = Calendar.getInstance();
calendar4.add(Calendar.HOUR,-1);//减一小时
System.out.println(sdf.format(calendar4.getTime()));
结果:
2023-06-26 16:56:48
2023-05-27 16:56:48
2022-06-27 16:56:48
2023-06-27 15:56:48
二、Calendar设置时间
System.out.println(sdf.format(date));//当期时间
Calendar calendar5 = Calendar.getInstance();
calendar5.add(Calendar.WEEK_OF_MONTH,1);
System.out.println(sdf.format(calendar5.getTime()));
Calendar calendar6 = Calendar.getInstance();
calendar6.add(Calendar.WEEK_OF_MONTH,1);//增加一周
calendar6.set(Calendar.DAY_OF_WEEK,3);//设置当前日期为本周周二, 3对应周二
System.out.println(sdf.format(calendar6.getTime()));
结果:
2023-06-27 16:55:36
2023-07-04 16:55:36
2023-07-04 16:55:36