calendar 时间类

╰+攻爆jí腚メ 2022-04-04 10:56 277阅读 0赞

给大家介绍下calendar 这个时间类吧，通常如果用到时间的话，就免不了需要用到这个类，希望大家有用

下面是代码，直接拿到main方法里面可以直接运行

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SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
        SimpleDateFormat format1 = new SimpleDateFormat("yyyy-MM-dd");
    
        Calendar calendar = Calendar.getInstance();
        calendar.set(Calendar.DAY_OF_MONTH,1);
        System.out.println(format1.format(calendar.getTime()) + "这月第一天");
    
        System.out.println( format1.format(Calendar.getInstance().getTime()) + "当天");
    
        System.out.println( format.format(Calendar.getInstance().getTime()) + "现在");
    
        calendar = Calendar.getInstance();
        calendar.set(Calendar.MONTH,0);
        calendar.set(Calendar.DAY_OF_MONTH,1);
        System.out.println(format1.format(calendar.getTime()) + "今年第一天");
    
        calendar = Calendar.getInstance();
        calendar.set(Calendar.DAY_OF_WEEK,2);
        System.out.println(format1.format(calendar.getTime()) + "这周第一天(星期一)");
    
        calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH,-1);
        calendar.set(Calendar.DAY_OF_MONTH,1);
        System.out.println(format1.format(calendar.getTime()) + "上月第一天");
    
        calendar = Calendar.getInstance();
        calendar.set(Calendar.DAY_OF_MONTH,0);
        System.out.println(format1.format(calendar.getTime()) + "上月最后一天");
    
        calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH,-2);
        calendar.set(Calendar.DAY_OF_MONTH,1);
        System.out.println(format1.format(calendar.getTime()) + "上上月第一天");
    
        calendar = Calendar.getInstance();
        calendar.add(Calendar.MONTH,-1);
        calendar.set(Calendar.DAY_OF_MONTH,0);
        System.out.println(format1.format(calendar.getTime()) + "上上月最后一天");
    
        calendar = Calendar.getInstance();
        calendar.add(Calendar.YEAR,-1);
        calendar.add(Calendar.MONTH,-1);
        calendar.set(Calendar.DAY_OF_MONTH,1);
        System.out.println(format1.format(calendar.getTime()) + "去年上月第一天");
    
        calendar = Calendar.getInstance();
        calendar.add(Calendar.YEAR,-1);
        calendar.set(Calendar.DAY_OF_MONTH,0);
        System.out.println(format1.format(calendar.getTime()) + "去年上月最后一天");

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运行结果如下

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