Java 判断时间是否在指定天数之内

 import java.util.Date;
 import java.text.SimpleDateFormat;

 public class WriteForBlog
 {
     static private int beforeDays = 8; // Use this vaule to judge the start date within 7 days.
     static private long beforeSeconds = beforeDays * 24 * 60 * 60 * 1000;

     public static void main(String[] args)
     {
         String strTime = "2016-10-28";
         if(isNewzt(strTime, beforeSeconds))
         {
             System.out.println("7 days old");
         }
         else
         {
             System.out.println("more than 7 days");
         }
     }

     private static boolean isNewzt(String theStrTime, long beforeDays)
     {
         boolean flag = false;
         if("0".equals(theStrTime))
         {
             return flag;
         }

         try
         {
             Date tDat = StrToDate(theStrTime, "");
             long thm = tDat.getTime();
             long chm=System.currentTimeMillis();
             if(thm + beforeDays >=chm)
             {
                 flag = true;
             }
         }
         catch(Exception e)
         {
             e.printStackTrace();
         }
         return flag;
     }

     private static Date StrToDate(String str, String formatStr)
     {
         if (null == formatStr || "".equals(formatStr))
         {
             formatStr = "yyyy-MM-dd";
         }

         SimpleDateFormat format = new SimpleDateFormat(formatStr);
         Date date = null;
         try
         {
             date = format.parse(str);
         }
         catch(Exception e)
         {
             e.printStackTrace();
         }
         return date;
     }

 }

忘记是参考哪个blog的。