Java Excel 列号数字与字母互相转换

在工作中Excel解析时，常常需要将列号的字母转换成对应的数字序号。

package test;


public class ExcelColumn {

    public static void main(String[] args) {
        String colstr = "AA";
        int colIndex = excelColStrToNum(colstr, colstr.length());
        System.out.println("'" + colstr + "' column index of " + colIndex);

        colIndex = 26;
        colstr = excelColIndexToStr(colIndex);
        System.out.println(colIndex + " column in excel of " + colstr);

        colstr = "AAAA";
        colIndex = excelColStrToNum(colstr, colstr.length());
        System.out.println("'" + colstr + "' column index of " + colIndex);

        colIndex = 466948;
        colstr = excelColIndexToStr(colIndex);
        System.out.println(colIndex + " column in excel of " + colstr);
    }

    /**
     * Excel column index begin 1