Tutorial. Interactive Forms Integration into Web Dynpro for Java Topic: Working with the PdfObject API

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1 Tutorial Interactive Forms Integration into Web Dynpro for Java Topic: Working with the PdfObject API At the conclusion of this tutorial, you will be able to: Generate PDF forms and fill them with XML data using the PdfObject interface Extract XML data from a PDF form using the PdfObject interface Think of a company that sends pre-filled forms to partners and gets filled forms back from them. In this scenario the PdfObject interface can be used to extract the data automatically for further processing. This tutorial shows two scenarios for using the PdfObject API. You will Generate a PDF form by using a template and an XML file with the corresponding data Extract and display data from a filled-in PDF form Note that while you don t need Web Dynpro to be able to work directly with the PdfObject, we have chosen to provide a user interface developed in Web Dynpro. Page 1 / 12

2 1 Overview The following screenshot shows what your final application will look like. In the upper view, a user can specify a data source and the target path for a new PDF document. By clicking Generate PDF, the internal template will be filled with the data supplied by the XML data source and the newly generated PDF will be written to the target path. In the lower view, the user can specify a PDF source. This PDF is the basis for extracting the complete data and writing it to the multi-line TextEdit or to fill the predefined TextViews at the bottom of the view. Page 2 / 12

3 2 Prerequisites To be able to use the PdfObject in Web Dynpro applications, the following prerequisites apply: 2-1 The SAP NetWeaver Developer Studio (Support Package Stack 11) including Adobe LiveCycle Designer (forms design tool) is installed on your computer. Use the SAP NetWeaver 04 installation CDs/DVDs if it is not yet installed. 2-2 You have access to the SAP J2EE Engine (Release 6.40). (Note that you can download an evaluation version (Sneak Preview SAP Web Application Server 6.40 Java) from the SDN Download Area at Adobe Reader is installed on your computer. If this is not the case, download Adobe Reader from the Adobe homepage ( at The Active Component Framework (ACF) of the Interactive Forms integration is installed on your computer. With SP Stack 11, calling a Web Dynpro application that includes a PDF form for the first time should automatically install the ACF in the background. If you experience difficulties that may be related to the frontend installation, please see SAP Note on the SAP Service Marketplace for manual installation. 2-5 The Adobe document services are configured on the SAP J2EE Engine you are using. To access the Installation and Configuration Guides for Adobe document services, go to SAP Web AS SAP Web AS 6.40 SR1 and Related Documentation Adobe Document Services. 2-6 Basic knowledge of developing Web Dynpro applications. For helpful information about Web Dynpro, go to 3 Importing a Project Template To restrict the development of this sample application to the actual content covered, there is a predefined Web Dynpro project template available in SDN under Web Dynpro Sample Applications and Tutorials. Follow the steps listed below to import the predefined Web Dynpro project: 3-1 Unzip the contents of the ZIP file TutWD_PdfObject_Init.zip into the work area of the SAP NetWeaver Developer Studio or into a local directory. Page 3 / 12

4 3-2 Start the SAP NetWeaver Developer Studio. 3-3 Import (File Import Multiple Project into Workspace) the Web Dynpro project TutWD_PdfObject_Init, and the J2EE projects TutWEB_PdfObject_Init, TutEJB_PdfObject_Init and TutEAR_PdfObject_Init. 3-4 The Web Dynpro project TutWD_PdfObject_Init, and the J2EE projects TutWEB_PdfObject_Init, TutEJB_PdfObject_Init and TutEAR_PdfObject_Init now appear in the corresponding explorer view (Web Dynpro and J2EE perspectives) within the SAP Netweaver Developer Studio. The information triggered by the Web Dynpro project TutWD_PdfObject_Init can be ignored at this time, since we will extend the Web Dynpro project during the remainder of this exercise and will thus remove the displayed information. Note: Depending on which Java compiler preferences are set, you may see some warnings in the Task view after importing the project. If the severity level for problems of type "Unused imports" (set in Window Preferences Java Compiler) has the value "Warning", the compiler will issue a warning for unused import references. Ignore these warnings! 4 Initial Project Structure After you have imported the Web Dynpro project template TutWD_PdfObject_Init, the following project structure is displayed in the Web Dynpro Explorer: Web Dynpro project structure Web Dynpro project: TutWD_PdfObject_Init Web Dynpro application: PdfObjectApp The application PdfObjectApp displays the interface view of the Web Dynpro component PdfObjectComp in the browser window. Web Dynpro component: PdfObjectComp This is the Web Dynpro component that contains our entire application. View: GenerateView In this view, you can generate a PDF form by clicking the button Generate PDF. In order to work properly, the application expects correct paths to the data source and to the target, which can be declared at the top of the view. View: ExtractView In this view, data of a specified PDF form can be extracted to the TextEdit as a whole as well as to single TextViews by clicking Get Data or Extract Data. Page 4 / 12

5 Window: PdfObjectWindow Initially contains a view set with two view areas represented by the two cells. (ViewSet Definition: GridLayout with one column and two rows). The two views Generate- and ExtractView are already embedded. After you have imported the J2EE project templates TutWEB_PdfObject_Init, TutEJB_PdfObject_Init and TutEAR_PdfObject_Init, the following project structure is displayed in the J2EE Explorer: J2EE project structure Enterprise Application project: TutEAR_PdfObject_Init The Enterprise Application project combines the EJB and the Web project. After completing the EJB Module you will be able to deploy the whole application through this project. (Note that two runtime references called tc/wd/pdflib and licensing, which refer to another library and another service, respectively, were added to the EAR project for you.) EJB Module project: TutEJB_PdfObject_Init Bean: PdfObjectBean This EJB stores the business logic for accessing the PdfObject. Web Module project: TutWEB_PdfObject_Init The web module stores the template needed for the generation of the PDF form. 5 Initialize Web Dynpro Context First, we want to extend the Init method of our Web Dynpro application so that the application starts with the right source and target path. After extracting the TutWD_PdfObject_Init.zip file, you will find two files called data.xml and result.pdf in the corresponding directory. Our Web Dynpro application needs these files at runtime to generate the PDF form or extract data from the PDF form. To avoid the manual editing of these paths, we will add them to the Init method of the Component Controller of the Web Dynpro Component called PdfObjectComp. 5-1 Switch to the Web Dynpro Perspective. 5-2 Navigate to TutWD_PdfObject_Init Web Dynpro Web Dynpro Components PdfObjectComp Component Controller. 5-3 Double-Click this node and switch to the Implementation tab. Page 5 / 12

6 5-4 Select the wddoinit() method from the outline view. 5-5 Go to the code lines listed below and customize the paths to your settings. // Customize the paths to your settings. // After that the TextEdits within the Web Dynpro application // will start with these values, because they are mapped to // this context. wdcontext.currentrequest_pdfobjectwsvidocument_createpdfelement().setdatasource("c:\\workspace\\tutwd_pdfobject\\data.xml"); wdcontext.currentrequest_pdfobjectwsvidocument_createpdfelement().setpdftarget("c:\\workspace\\tutwd_pdfobject\\result.pdf"); Save the new metadata by choosing the (Save All Metadata) icon from the toolbar. From now on, you do not have to manually edit the paths after loading the application. 6 Implement the Business Logic The other way around To make the application work, we first need the business logic. The EJB acts as a Web Service and provides methods to the Web Dynpro application. Switch to the J2EE Perspective, choose the J2EE Explorer and navigate to TutEJB_PdfObject_Init ejbmodule com sap tut ejb pdfobjectservices and double-click PdfObjectBean.java. Within this Bean you will find the (unfortunately) empty methods createpdf(), getdata() and extractdata(). Create a PDF form The method createpdf() expects a data source, a target for the new PDF file, a template, a user name and your local settings. In the first step, the data must be read. Replace the current return statement with the following code within the createpdf() method: Page 6 / 12

7 boolean returnvalue = false; ByteArrayOutputStream datasourceoutputstream = new ByteArrayOutputStream(); ByteArrayOutputStream templatesourceoutputstream = new ByteArrayOutputStream(); try { // get template file as InputStream InputStream datasourceinputstream = new FileInputStream(new File(dataSource)); InputStream templatesourceinputstream = getclass().getclassloader().getresourceasstream( "apps/sap.com/tutear_pdfobject/servlet_jsp/contextroot /root/template.xdp"); // convert InputStream to OutputStream IOUtil.write(dataSourceInputStream, datasourceoutputstream); IOUtil.write(templateSourceInputStream, templatesourceoutputstream); datasourceinputstream.close(); templatesourceinputstream.close(); catch (Exception e) { throw new EJBException(e.getMessage()); Now, all the necessary information is stored in temporary memory. The data source was fetched from the specified file and is now stored in an InputStream. The template is stored in the TutWEB_PdfObject_Init project. EJBs must not access these files through the file system. But it is possible to stream these files through the getresourceasstream() method of the corresponding ClassLoader (available through getclass().getclassloader()). All other settings are passed as parameters. The next step is to create a PdfObject and fill it with the data. For that purpose, the PdfObject supplies setter methods for each parameter. The following code shows how to do this. Append it at the end of the createpdf() method. // create an instance of PdfObject and set the attributes IWDPDFObject pdfobject = WDPDFObjectFactory.getPDFObject(); pdfobject.setdata(datasourceoutputstream); pdfobject.settemplate(templatesourceoutputstream); pdfobject.setusername(username); pdfobject.setlocale(new Locale(locale)); pdfobject.setusagerights(null, PDFObject.getAllUsageRights()); pdfobject.setinteractive(true); // create the PDF and store it as ByteArrayInputStream ByteArrayInputStream pdfinputstream = (ByteArrayInputStream) pdfobject.createpdf(); The PdfObject now stores all the data. Page 7 / 12

8 The last step in this method is to write the data to a file. This code below appended to the method fulfills our needs: if (pdfinputstream!= null) { try { // Write PDF to hard disk FileOutputStream fileoutputstream = new FileOutputStream(new File(pdfTarget)); IOUtil.write(pdfInputStream, fileoutputstream); fileoutputstream.flush(); fileoutputstream.close(); returnvalue = true; catch(exception e) { throw new EJBException(e.getMessage()); return(returnvalue); Choose Source Organize Imports from the context menu. This will automatically add all necessary import statements to your source code. The createpdf() method is now ready to use. It returns a boolean value indicating whether it succeeded or failed during generation. The link to Web Dynpro will be implemented later. Save your code by pressing the Save button toolbar. on the SAP NetWeaver Developer Studio Get data from a PDF form In the next step, we need a method to extract data from an existing PDF form. First, the form must be read: Double-click the node called getdata(string) in the outline. The source code view automatically switches to the declaration of this method. To provide the form as a stream to the PdfObject, you need the code below. Remove the return statement from the getdata() method, and add the code below instead: ByteArrayOutputStream pdfsourceoutputstream = new ByteArrayOutputStream(); try { // get PDF as InputStream InputStream pdfsourceinputstream = new FileInputStream(new File(pdfSource)); IOUtil.write(pdfSourceInputStream, pdfsourceoutputstream); pdfsourceinputstream.close(); catch (Exception e) { throw new EJBException(e.getMessage()); Next, we need a PdfObject that reads the stream and provides methods to read the form data. Append the code below to achieve this goal: Page 8 / 12

9 // create an instance of PdfObject and set the PDF you just // fetched as PDF attribute. IWDPDFObject pdfobject = WDPDFObjectFactory.getPDFObject(); pdfobject.setpdf(pdfsourceoutputstream); // get data from PDF (represented as XML) ByteArrayInputStream datainputstream = (ByteArrayInputStream) pdfobject.getdata(); As you can see, the simple method pdfobject.getdata() is the key in this section. All data (formatted as XML) returns as a stream. To return a String the following coding must be appended: if (datainputstream == null) return(null); else { try { String output = formatdata((inputstream) datainputstream); return(output); catch (Exception e){ throw new EJBException(e.getMessage()); You may have recognized the method formatdata(). This simple helper method was used to format the resulting XML. If you want to use your own formatting, feel free to edit the formatdata() method. Choose Source Organize Imports from the context menu. This will automatically add all necessary import statements to your source code. Now, you are able to extract from the PDF form as an XML-formatted string data entered in it. Save your code by pressing the Save button toolbar. on the SAP NetWeaver Developer Studio Extract single data and fill a Data Transfer Object (DTO) The getdata() method discussed above only extracts the form data as a whole. We will now implement a method to split the data up and set the values we receive to a Data Transfer Object (DTO). This DTO provides setter methods which will reduce the amount of work and simplify the task. Navigate to the method extractdata() (e.g. by using the outline view). Add the following simple coding between the declaration and the return statement: Page 9 / 12

10 // get XML data xmldata = getdata(pdfsource); // get the values from the XML and set them to the context. travelrequestdata.setname(getitemvalue("name")); travelrequestdata.setdepartment(getitemvalue("department")); travelrequestdata.setcostcenter(getitemvalue("costcenter")); travelrequestdata.setarrivaldate(getitemvalue("arrvialdate")); travelrequestdata.setdeparturedate(getitemvalue("departuredate")); travelrequestdata.setdestinationcountry(getitemvalue("destinationcountry")); travelrequestdata.setdestinationcity(getitemvalue("destinationcity")); travelrequestdata.settravelby(getitemvalue("travelby")); travelrequestdata.settravelcausedby(getitemvalue("travelcausedby")); travelrequestdata.sethotelneeded( new Boolean(getItemValue("IsHotelNeeded")).booleanValue()); First, we make use of the getdata() method to retrieve the complete XML. This data is stored temporarily in xmldata. A method called getitemvalue() which we implemented for you uses this data and extracts the value of the corresponding node in a simple manner. For complex XML structures, you will need to create your own method to extract single values from a node. The XML Parser packages (SAX or W3C DOM) supplied by the J2EE API are very suitable for this task. Choose Source Organize Imports from the context menu. This will automatically add all necessary import statements to your source code. Your EJB now provides all the methods needed by the Web Dynpro application. Save your code by pressing the Save button toolbar. on the SAP NetWeaver Developer Studio 7 Making the Link Add a Web Service to the EJB In chapter 5, you completed the code for the business logic to access the PdfObject. Unfortunately, so far there is no connectivity between this logic and the Web Dynpro application. To achieve this, you need to add a Web service to the EJB. This Web service allows external applications to access the EJB methods. The SAP NetWeaver Developer Studio offers a wizard for creating Web services. 7-1 Switch to the J2EE Explorer within the J2EE Perspective. 7-2 Navigate to TutEJB_PdfObject_Init ejb-jar.xml PdfObjectBean. Page 10 / 12

11 7-3 Open the context menu of the node by right-clicking onto it. 7-4 Choose New Web Service. A wizard appears. Enter PdfObjectWS as Web Service Name and click Finish. That s it! After building the archives (WEB, EJB and EAR) and deploying it to the J2EE engine, you can test your Web Service without creating a sample application. 8 Building, Deploying and Running the Project To complete this tutorial, you need to build all projects and deploy the EAR and the Web Dynpro application. To do so, proceed as follows: Switch to the J2EE perspective. Right-click TutWEB_PdfObject_Init and choose Build WEB Archive. Then right-click TutEJB_PdfObject_Init and choose Build EJB Archive. Finally, right-click TutEAR_PdfObject_Init and choose Build Application Archive. You have now built all the archives in the J2EE perspective. Now navigate to TutEAR_PdfObject_Init TutEAR_PdoObject.ear. Open the context menu by right-clicking the node and choose Deploy to J2EE engine. Page 11 / 12

12 Next, switch to the Web Dynpro perspective, Rebuild the project and Deploy New Archive and Run (the latter from the context menu of the PdfObjectApp node under Web Dynpro -> Applications). A browser window with a log-on screen appears. Use your J2EE user (with administrator rights) and password to log on. After successful logon, the browser window changes to the view you know from the overview section (chapter 1). You have now completed the tutorial that demonstrates the usage of the PdfObject. 9 Test Web Service without Sample Application You can test your deployed Web service using SAP NetWeaver Developer Studio without having to generate a sample application on your own. Switch to the Web Services perspective in SAP NetWeaver Developer Studio. If it is not in your list of perspectives, choose Open a Perspective, and the screen in the screenshot below appears. Select Web Services. Go to the Web Service Navigator (normally located in the bottom right window of SAP NetWeaver Developer Studio). Expand the node Servers and its subnode, which represents the server you are deploying on. All available Web services are listed. Select the Web service called PdfObjectWS and double-click it. The Web service overview appears in the top right window of SAP NetWeaver Developer Studio. Select Test from the menu in this view. You can now choose which method you would like to test. Remember that in each case you need to provide the necessary parameters expected by the method. Page 12 / 12