Content-Disposition文件名乱码转码问题

public String getFileName(String urlStr){
        String fileName = null;
        try {
            URL url = new URL(urlStr);
            URLConnection uc = url.openConnection();
            fileName = uc.getHeaderField("Content-Disposition");
            fileName = new String(fileName.getBytes("ISO-8859-1"), "GBK");
            fileName = URLDecoder.decode(fileName.substring(fileName.indexOf("filename=")+9),"UTF-8");
            log.info("文件名为：" + fileName + "  大小" + (uc.getContentLength()/1024)+"KB");
        } catch (Exception e) {
            e.printStackTrace();
        }
        return fileName;
    }