5. Executing the template to create PDF files

Once you have generated the XSL-FO file you can use Apache FOP for converting your XML files to PDF.

However we provide the following class:

com.java4less.xreport.fop.FOProcessor

which has a very simple interface:

/**

• generate PDF file for XML document

  @param xmlStream input XML document
  @param xsltStream XSL-FO file as created by the designer
  @param os output PDF file
  @throws Exceptio

*/

public void process(InputStream xmlStream, InputStream xsltStream,OutputStream os) throws Exception {

for example:

FOProcessor processor=new FOProcessor();

processor.process(new FileInputStream("Order.xml"), new FileInputStream("order.fo") , new FileOutputStream("report.pdf"));

FOP web server (servlet)

The delivery includes a WAR file which can be deployed on a web server. This includes a servlet that operates as follows:

1. It receives a HTTP request using the POST method.
• The body of the request contains the XML document to be converted
• or the body contains a FORM and in the form there is a text field that contains the XML data. In this case the parameter DATAFIELD must provide the name of the field (see file Example.html)
2. In the URL of the servlet you provide the name of the XSL-FO file to be used for the conversion, using the TEMPLATE parameter. The template must be the name of the file and it must be placed in the default working directory of the server (it is also possible to provide the file as a relative or absolute file name). As an alternative the file can be located within the war file in the WEB-INF/classes subdirectory or below it.
3. the servlet returns the PDF file

The delivery includes the following files that you can use for testing:

•     departmentEmployees.included inside the war file (directory WEB-INF/classes).
•     the war file: web/J4LFOPServer.war

You can test the servlet by deploying the war file and then executing the URL:

http://servername/J4LFOPServer/Example.html

When you click on the button the following URL will be openned:

http://localhost:8080/J4LFOPServer/servlet? TEMPLATE=departmentEmployees.fo&ENCODIN G=iso-8859-1&DATAFIELD=S1

Where

• the file departmentEmployees.fo is inside the war file
• encoding ISO-8859-1 is the encoding of the input data
• S1 is the name of the text field that contains the XML data. Note, if the DATAFIELD is missing, the servlet assumes the body of the HTTP request contains the XML payload.

JAXBContext jc = JAXBContext.newInstance(PurchaseOrderHeader.class);
Marshaller marshaller=jc.createMarshaller();
ByteArrayOutputStream ba=new ByteArrayOutputStream();
marshaller.marshal(po,ba);

7/3. create now the PDF output for the XML data
FOProcessor processor=new FOProcessor();
processor.process(new ByteArrayInputStream(ba.toByteArray()), new FileInputStream("JavaPOExample.fo") , new FileOutputStream("JavaPOExample.pdf"));

You can use the file POTest.bat for testing the delivered files.

Sending the PDF as an email attachment

This option is currently available only for the APEX server, please check the APEX specific documentation.

Adding a digital signature to the PDF file

You can add a digital signature to the PDF files you generate. This signature ensures the integrity of your document and its authentication. In other words, the receiver of the document knows you have created that document (authentication) and no one has modified it (integrity). The signature created will use the algorithms RSA signature, SHA1 hash and PKCS7 encoding.

The signature can be created in the design environment for testing purposes and of course also in the runtime environment. Please read the environment specific document (for example Apex) to learn how to activate the signature.

The rest of this section describes how to test the digital signature in the designer and view it in Acrobat reader.

In order to activate the digital signature you use the preferences window. In this window you activate the signature and select the p12 or pfx file which contains the private key used for the signature. Note our product contains a test certification authority (CA) and a test certificate in the certs subdirectory. You can use these for testing purposes.

If you have enabled the signature in the settings window, each time you generate a PDF file with the PDF button, the designer will ask for the password of the p12 file. The password of the test file we provide is test.

Note, if you click on the cancel button, the PDF file will be created without the signature.

Once you open the created file, you will notice Acrobat reader warns you with the text "the signature has problems". The reason for this is, Acrobat does not know the certificate authority (CA) we have used for creating the test certificate. Looking at the signature closely in the signatures panel you will see:

• The PDF reader says the document has not been modified since the signature has been applied (integrity of the document).
• The signer's identity is unknown since the reader does not know our test CA.
  
  

If you however click on the certificate details link and add the CA certificate as a trusted certificate, you will see the reader now accepts the signature.