java关于日期_calendar.getinstance()如何设置日期为10天前-优快云博客

本文链接：https://blog.youkuaiyun.com/qq_25635139/article/details/88632438

博客给出一段Java代码，定义了一个静态方法isThisMonth，用于判断传入的日期是否为本月。方法通过SimpleDateFormat格式化日期，将参数时间和当前时间对比，若相等则返回true，否则返回false。

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//判断选择的日期是否是本月
public static boolean isThisMonth(Date lastUpdatedate) {
    SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM");
    String param = sdf.format(lastUpdatedate);//参数时间 2019-06
    String now = sdf.format(new Date());//当前时间 2019-07
    if (param.equals(now)) {
        return true;
    }
    return false;
}
@PostMapping(value = "/log/time")
public Map<String, String> time(){
    Map<String,String> map = new HashMap<>();
    SimpleDateFormat day = new SimpleDateFormat("yyyy-MM-dd");//设置日期格式

    //获取当天时间
    String today = day.format(new Date());// new Date()为获取当前系统时间

    //获取近三天前时间
    Calendar calendar = Calendar.getInstance();
    calendar.add(Calendar.DATE, -3);
    String threeDaysAgo = day.format(calendar.getTime());

    //获取近一个月
    Calendar calendarOne = Calendar.getInstance();
    calendarOne.setTime(new Date());
    calendarOne.add(Calendar.MONTH, -1);
    Date m = calendarOne.getTime();
    String oneMonths = day.format(m);

    //获取近三个月
    Calendar calendarTree = Calendar.getInstance();
    calendarOne.setTime(new Date());
    calendarOne.add(Calendar.MONTH, -3);
    Date mt = calendarOne.getTime();
    String threeMonths = day.format(mt);

    map.put("today", today);
    map.put("threeDaysAgo",threeDaysAgo);
    map.put("oneMonths", oneMonths);
    map.put("threeMonths", threeMonths);

    return map;
}