Java download file name garbled problem

    String userAgent = request.getHeader("User-Agent");  
    String formFileName = file.getFileName();  
        
    // 针对IE或者以IE为内核的浏览器：  
    if (userAgent.contains("MSIE") || userAgent.contains("Trident")) {  
        formFileName = java.net.URLEncoder.encode(formFileName, "UTF-8");  
    } else {  
        // 非IE浏览器的处理：  
        formFileName = new String(formFileName.getBytes("UTF-8"), "ISO-8859-1");  
    }  
    response.setHeader("Content-disposition",String.format("attachment; filename=\"%s\"", formFileName));  
    response.setContentType("multipart/form-data");   
    response.setCharacterEncoding("UTF-8");