using System;
using Blue;

public class GetFileNameUtility : IUtility
{
    private string fileName="";
    public string GetFileName(string url,string fileType)
    {
        int index = url.IndexOf(fileType);
        if(index<0) throw new Exception("URL下载链接或者文件类型不规范");

        for(int i= index; i>0; i-- )
        {
            if(url[i]=='/')
            {
                fileName = url.Substring(i+1,index-i-1)+fileType;
                break;
            }
        }
        return fileName;
    }
}