using Apache FOP to generate PDF from Java value objects

[Prash Negu]

Hi,

I am trying to explore Apche FOP library to create PDF documents and gone through all the examples.

In my application, we query database and get the value objects (java beans) and out of this we need to create PDF files. I looked at ExampleJavatoPDF, for me it looks too much of code (with SAXSource). I was thinking to use JAXB annotations (jaxb is shipped with JDK1.6) and generate XML stream on the fly and apply XSL to generate PDF.

The code looks as below.

JAXBContext context = JAXBContext.newInstance(valueObj.getClass()); 
Marshaller m = context.createMarshaller(); 

ByteArrayOutputStream xmlOut = new ByteArrayOutputStream(); 
m.marshal(valueObj, xmlOut); 
byte[] o = xmlOut.toByteArray(); 
xmlOut.close(); 
ByteArrayInputStream in = new ByteArrayInputStream(o); 

Source src = new StreamSource(in); 
Result res = new SAXResult(fop.getDefaultHandler()); 
transformer.transform(src, res); 

It works fine. My question is, is it best practice to generate PDF files from Java Objects? Is there a better way? Can we generate XSL-FO from Java objects?

Thanks in advance.

Regards,
Prashant

[Colm Dickson]

Hello.

I'm no expert but I've been playing around with Xml to Pdf like you and from what I have seen you can generate XSL-FO document automatically but you have to have an XSLT document with the :fo directives embedded into it. The XSLT document can be used in a java program to output the XSL-FO document and then you need to use then Apache FOP driver to run the FO document against your Xml to produce the Pdf. It's a two stage process.XSLT to XSL-FO and XSL-FO to PDF. I'm sorry I have no examples right now but I have seeen this in the book 'PRO XML DEVELOPMENT WITH JAVA TECHNOLOGY' by Apress.

Colm