//方法一

SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");

String maxDateStr = "2018-01-01";

String minDateStr = "";

Calendar calc =Calendar.getInstance();

try {

calc.setTime(sdf.parse(maxDateStr));

calc.add(calc.DATE, -30);

Date minDate = calc.getTime();

minDateStr = sdf.format(minDate);

System.out.println("minDateStr:"+minDateStr);

} catch (ParseException e1) {

e1.printStackTrace();

}

方法二:

Calendar now = Calendar.getInstance();

now.add(Calendar.DAY_OF_MONTH, -30);

String endDate = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss").format(now.getTime());

System.out.println(endDate);

方法三：

//java8 新特性

LocalDateTime now = LocalDateTime.now();

now = now.minus(30, ChronoUnit.DAYS);

System.out.println(now.toString());

方法四：

import org.apache.commons.lang3.time.DateUtils;

Date now = new Date();

Date startDate = DateUtils.addDays(now, -30);

方法五：

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

Calendar c = Calendar.getInstance();

//过去七天

c.setTime(new Date());

c.add(Calendar.DATE, - 7);

Date d = c.getTime();

String day = format.format(d);

System.out.println("过去七天："+day);

//过去一月

c.setTime(new Date());

c.add(Calendar.MONTH, -1);

Date m = c.getTime();

String mon = format.format(m);

System.out.println("过去一个月："+mon);

//过去三个月

c.setTime(new Date());

c.add(Calendar.MONTH, -3);

Date m3 = c.getTime();

String mon3 = format.format(m3);

System.out.println("过去三个月："+mon3);

//过去一年

c.setTime(new Date());

c.add(Calendar.YEAR, -1);

Date y = c.getTime();

String year = format.format(y);

System.out.println("过去一年："+year);

标签：Java,format,30,System,时间,Date,new,Calendar,now

来源： https://www.cnblogs.com/zhangzhiping35/p/14352536.html