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Friday, 1 August 2014

Exporting viewObject data in text file using af:fileDownloadActionListener in Oracle ADF (12.1.3)

Hello All
This post is about using af:fileDownloadActionListener to generate file on run-time, suppose i have a viewObject and i want to export it's data in CSV or plain text so for this requirement we can generate file at run-time and send it to client UI to download

What is af:fileDownloadActionListener-
as per oracle docs-
The fileDownloadActionListener tag is a declarative way to allow an action source (<commandButton>, <commandLink>, etc.) to programatically send the contents of a file to the user, optionally with a specific content type and filename. Since file downloads must be processed with an ordinary request - not XMLHttp AJAX requests - this tag forces partialSubmit to be false on the parent component, if it supports that attribute.
The fileDownloadActionListener uses the native (browser built-in) filedownload popup, so this popup cannot be configured.

In this post i am using Departments table of HR schema



  • Prepare model part using Departments table and drop it on page as a table and add a button to UI for downloading


  • drop af:fileDownloadActionListener as child of button and set it's property as contentType, method , fileName 


  • Now see code written in download Listener-

  •     /**Method to get BindingsContainer for current page
         * @return
         */
        public BindingContainer getBindingsCont() {
            return BindingContext.getCurrent().getCurrentBindingsEntry();
        }
    
        /**Method to download ViewObject's data in plain text file
         * @param facesContext
         * @param outputStream
         * @throws UnsupportedEncodingException
         * @throws IOException
         */
        public void fileDownloadListener(FacesContext facesContext,
                                         OutputStream outputStream) throws UnsupportedEncodingException, IOException {
            OutputStreamWriter w = new OutputStreamWriter(outputStream, "UTF-8");
            //Get itertaor from bindings
            DCIteratorBinding deptIter = (DCIteratorBinding) getBindingsCont().get("Departments1Iterator");
            //Get ViewObject from Iterator
            ViewObjectImpl vo = (ViewObjectImpl) deptIter.getViewObject();
            ViewAttributeDefImpl[] attrDefs = vo.getViewAttributeDefImpls();
            int count = 0;
            RowSetIterator rsi = vo.createRowSetIterator(null);
            while (rsi.hasNext()) {
                Row nextRow = rsi.next();
                if (nextRow != null) {
                    // Code to iterate over ViewObject's column to get all columns value at runtime
                    for (ViewAttributeDefImpl attrDef : attrDefs) {
                        byte attrKind =
                            attrDefs[count].getAttributeKind(); //checks attribute kind for each element in an array of AttributeDefs
                        if (attrKind != AttributeDef.ATTR_ASSOCIATED_ROW &&
                            attrKind != AttributeDef.ATTR_ASSOCIATED_ROWITERATOR) {
                            String columnName = attrDef.getName();
                            w.write(columnName + " - " + nextRow.getAttribute(columnName) + "  ");
                        }
                    }
                    // Code to create new line text line for new Row
                    w.write(System.getProperty("line.separator"));
                }
            }
            //Flush the writer after wrting file
            w.flush();
        }
    }
    

  • Run this application and click on download button, browser download box appears , open downloaded file and see how your data appears in text file, to export data in a pdf file you have to generate PDF file using some API then you can download it in same way


Cheers:) Happy Learning

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