java编程实现根据EXCEL列名求其索引的方法

/*  * To change this template, choose Tools | Templates  * and open the template in the editor.  */ import java.util.HashMap; import java.util.Map; /**  *  * @author jdkleo  */ public class ExcelUtil {   public static int getCellNum(String cellStr) {     char[] cellStrArray = cellStr.toUpperCase().toCharArray();     int len = cellStrArray.length;     int n = 0;     for(int i=0;i<len;i++){       n += (((int)cellStrArray[i])-65+1)*Math.pow(26, len-i-1);     }     return n-1;   }   public static void main(String[] args) {     System.out.print(getCellNum("aaa"));   } }