Thursday, 22 January 2015

Show uploaded file (pdf/text/html/xml/image) content on page -Oracle ADF

Hello all
In previous post
Uploading and downloading files from absolute server path in Oracle ADF (12.1.3)
we saw that how can we upload any file to absolute server path and download same from there.
Uploading part is done using simple java code to write file to specified folder and downloading part is done using <af:fileDownloadActionListener>

Now in this post i am going to show that how can we display a file on page directly without downloading it.
So for this i am using same sample application that i have used in previous post , you can download it from here
See the additional steps to show file content on page-
  • Create a servlet to parse file into output stream , this output stream will be used to show file content further.
    To create servlet right click on viewController project select New--->From Gallery-->Web Tier-->Servlet




  • See servlet source code to parse file into outputStream

  • import java.io.BufferedInputStream;
    import java.io.File;
    import java.io.FileInputStream;
    import java.io.IOException;
    import java.io.InputStream;
    import java.io.OutputStream;
    import java.io.PrintWriter;
    
    import javax.servlet.*;
    import javax.servlet.http.*;
    
    public class PreviewFileServlet extends HttpServlet {
        private static final String CONTENT_TYPE = "text/html; charset=UTF-8";
    
        public void init(ServletConfig config) throws ServletException {
            super.init(config);
        }
    
        /**
         * @param request
         * @param response
         * @throws ServletException
         * @throws IOException
         */
        public void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
            String path = (request.getParameter("path"));
    
            OutputStream os = response.getOutputStream();
            //If path is null
            if (path.equalsIgnoreCase("No")) {
                path = "D:\\Document\\ItemImage\\Item.jpg";
            }
            if (request.getParameter("path") == "") {
                path = "D:\\Document\\ItemImage\\Item.jpg";
            }
            InputStream inputStream = null;
    
            try {
                File outputFile = new File(path);
                inputStream = new FileInputStream(outputFile);
                BufferedInputStream in = new BufferedInputStream(inputStream);
                int b;
                byte[] buffer = new byte[10240];
                while ((b = in.read(buffer, 0, 10240)) != -1) {
                    os.write(buffer, 0, b);
                }
    
            } catch (Exception e) {
    
                System.out.println(e);
            } finally {
                if (os != null) {
                    os.close();
                }
                if (inputStream != null) {
                    inputStream.close();
                }
    
            }
        }
    }
    

  • Now open page in editor and drop an af:inlineFrame from component palette . inlineFrame is used to create a frame to show any external page or document just like as HTML iframe , it is loaded from source attribute
    So here i am using servlet as source attribute for this inlineFrame

  • <af:inlineFrame id="if2"
                                                        source="/previewfileservlet?path=#{bindings.Path.inputValue == null ? 'No' : bindings.Path.inputValue}"
                                                        inlineStyle="height:350px;width:800px;" sizing="preferred"/>
    

    here path of document is added to pageDef bindings that is passed to servelt as parameter

  • Now run this application and check it

    View Text File-
          View PDF File-


Thanks, Happy Learning :)

Post Related to file handling in Oracle ADF- 

Uploading and showing image file from absolute server path -Orace ADF
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Download file from url using Oracle ADF & Java- Download Manager
Reading html source of a webpage (url) using Oracle ADF (af:richTextEditor) & Java