给定一个16进制字符串，返回10进制数

private static int getDecimal(String strHex){
        
        char[] t = {'0','1','2','3','4','5','6','7','8','9','a','b','c','d','e','f'};
        int len = strHex.length();
        int result = 0;
        for(int i = len;i>0;i--){
            char c = strHex.charAt(i-1);
            for(int j=0;j<t.length;j++){
                if(c==t[j]){
                    result+=j<<((len - i )*4);
                }
            }
        }
        return result;
    }