grails file download + image viewing

/**
 * 下载
 * @return
*/
def download(){
    def fileObj = ValuationHistoryForNSQ.get(params["id"])
    def file_name = fileObj.getFile_name()
    def file_type = fileObj.getFile_type()
    def root_path = fileObj.getRoot_path()
    def file_path = fileObj.getFile_path()
    def downloadPath = root_path+file_path+file_name

    def bis = new BufferedInputStream(new FileInputStream(downloadPath))
    def bos = new BufferedOutputStream(response.outputStream)

    long fileLength = new File(downloadPath).length()

    response.setCharacterEncoding("UTF-8")
    response.setContentType("multipart/form-data")

    String userAgent = request.getHeader("User-Agent").toLowerCase()

    if ( userAgent.contains( "msie" ) || userAgent.contains( "like gecko" ) ){
         // ie for win10 ie edge browser and other systems
 file_name = URLEncoder. encode (file_name, "UTF-8" )
    }else {
        file_name = new String(file_name.getBytes("UTF-8"), "iso-8859-1")
    }

    response.setHeader("Content-disposition", 
	String.format("attachment; filename=\"%s\"", file_name))
    response.setHeader("Content-Length", String.valueOf(fileLength))

    byte [] buff = new byte [ 2048 ]
     int bytesRead
     while (- 1 ! = (bytesRead = bis.read (buff, 0 , buff. length ))) {
        bos.write(buff, 0, bytesRead)
    }
    bis.close()
    bos.close()
}

/**
 * 查看图片
 * @return
*/
def look(){
    def fileObj = ValuationHistoryForNSQ.get(params["id"])
    def file_name = fileObj.getFile_name()
    def file_type = fileObj.getFile_type()
    def root_path = fileObj.getRoot_path()
    def file_path = fileObj.getFile_path()
    def downloadPath = root_path+file_path+file_name

    //Read the local image input stream
 FileInputStream inputStream = new FileInputStream(downloadPath);
     int i = inputStream.available();
     //byte array is used to store image byte data
 byte [] buff = new byte [i];
    inputStream.read(buff);
    //Remember to close the input stream
 inputStream.close();
     //Set the content type of the response sent to the client
 response.setContentType( "image/*" );
    OutputStream out = response.getOutputStream();
    out.write(buff);
    //Close the response output stream
 out.close();
}

View image front desk method:

<a href="javascript:void(0)" class="btn btn-xs btn-primary btn-outline" 

onclick="look(${it?.id})">查看</a>

function look(id) {
    var srcPath = '/valuationHistoryForNSQ/look?id='+id
    var imgPath = '<img src="'+srcPath+'" width="800px" height="500px">'
    layer.open({
        type: 1 //Page层类型
        ,area: ['800px', '542px']
        , title : 'View'
        , scrollbar : false //Block the browser scroll bar
        , shade : 0.6 //mask transparency
        , maxmin : false //Allow full screen minimization
        , anim : 5 //The animation form of 0-6, -1 is not enabled
        ,content: imgPath
});
}

grails file download, pay attention to the Chinese garbled problem, my file path and file name are found from the database.

I use win10 system, it is worth noting the difference between win10 ie and edge and other browsers