import java.text.SimpleDateFormat;
import java.util.Calendar;
public class CaculateDate {
/**计算日期
* @param num 日期区间大小
* @param type 日期区间类型
* @return 日期
*/
public String caculateDateTime(int num, String type) {
String resultDateTime = null;
Calendar cc = Calendar.getInstance();
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
try {
if (type.equals("day"))
num = num * 1;
else if (type.equals("week"))
num = num * 7;
else if (type.equals("month"))
num = num * 30;
else if (type.equals("quarter"))
num = num * 90;
else if (type.equals("half a year"))
num = num * 180;
else if (type.equals("year"))
num = num * 365;
cc.add(Calendar.DAY_OF_MONTH, -num);
resultDateTime = sdf.format(cc.getTime());
} catch (Exception e) {
System.out.println(e.getMessage());
}
return resultDateTime;
}
/**样例
* @param args
*/
public static void main(String[] args) {
CaculateDate c = new CaculateDate();
System.out.println(c.caculateDateTime(1, "day"));
}
}
假如现在是2013-08-10 19:59:08,它的计算结果如下:
可能会应用到的地方:
1.商城计算一段时间内的商品数目;
2.在一段时间内的访问量;