程序代码：

public class TestString
{
    public static void main(String[] args)
    {
        String str = "BA01PG01001";
        str = formatStr(str);
        System.out.print(str);


    }

    public static String formatStr(String str)
    {
        str = str.substring(0,4) + "-" + str.substring(4,6) + "-"
            + str.substring(6,8) + "-" + str.substring(8,11);
        return str;

    }
}