//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);