Open pdf file in new window from variable path name in GSP page

Question

I have a map named file I\'m receiving from my controller which contains the path and description of a file stored in assets/myfiles/file.pdf the following form

Answer 1

Create Controller Method And Write A Connection To Download Your File.

GSP:
Write the Button And Create A link To this Controller Action In Your GSP like below.

<g:link class="btn btn-info btn-sm" 
      action="downloadMyFile" resource="${instance}" 
                           target="_blank">DOWNLOAD FILE</g:link>

Controller:

        // This is Used To Open PDF File. 
        def downloadMyFile(){
            def file = new File("download/path/to/your/file")
            response.setContentType("application/pdf")
            response.setHeader("Content-disposition", "filename=${file.getName()}")
            response.outputStream << file.newInputStream()     
        }

[OR]

        // This is Simply Download Your File.  
        def downloadFile(){
             def file = new File("Path/to/your/File")
             response.setContentType("application/octet-stream")
             response.setHeader("Content-disposition", "filename=${file.getName()}")
             response.outputStream << file.newInputStream()  
        }

Note:

resource : You can pass Instance to your download action.
target="_blank" : Open/Download File In New Tab.
action : Action name that is defined in Controller.