java,取30天前的日期
阿新 • • 發佈:2019-01-03
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); String maxDateStr = "2017-02-08"; 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);//minDateStr:2017-01-09 正確!!!! } catch (ParseException e1) { // TODO Auto-generated catch block e1.printStackTrace(); } // SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); // String maxDateStr = "2017-02-08"; // String minDateStr = ""; // try { // Date minDate = new Date(sdf.parse(maxDateStr).getTime() - (30-1)*24*3600*1000);//minDateStr:2017-02-28 錯誤的!!!!!! // minDateStr = sdf.format(minDate); // System.out.println("minDateStr:"+minDateStr); //"2017-02-06"<= ... <= "2017-02-08" //3天 // } catch (ParseException e1) { // // TODO Auto-generated catch block // e1.printStackTrace(); // }
前30天日期序列
0:minDateStr:2017-02-08SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd"); String maxDateStr = "2017-02-08"; String minDateStr = ""; Calendar calc =Calendar.getInstance(); try { for(int i=0;i<30;i++){ calc.setTime(sdf.parse(maxDateStr)); calc.add(calc.DATE, -i); Date minDate = calc.getTime(); minDateStr = sdf.format(minDate); System.out.println(i+":minDateStr:"+minDateStr);//minDateStr:2017-01-09 正確!!!! } } catch (ParseException e1) { // TODO Auto-generated catch block e1.printStackTrace(); }
1:minDateStr:2017-02-07
2:minDateStr:2017-02-06
3:minDateStr:2017-02-05
4:minDateStr:2017-02-04
5:minDateStr:2017-02-03
6:minDateStr:2017-02-02
7:minDateStr:2017-02-01
8:minDateStr:2017-01-31
9:minDateStr:2017-01-30
10:minDateStr:2017-01-29
11:minDateStr:2017-01-28
12:minDateStr:2017-01-27
13:minDateStr:2017-01-26
14:minDateStr:2017-01-25
15:minDateStr:2017-01-24
16:minDateStr:2017-01-23
17:minDateStr:2017-01-22
18:minDateStr:2017-01-21
19:minDateStr:2017-01-20
20:minDateStr:2017-01-19
21:minDateStr:2017-01-18
22:minDateStr:2017-01-17
23:minDateStr:2017-01-16
24:minDateStr:2017-01-15
25:minDateStr:2017-01-14
26:minDateStr:2017-01-13
27:minDateStr:2017-01-12
28:minDateStr:2017-01-11
29:minDateStr:2017-01-10