Contribution is important in the open source community, and one project that I had meant to contribute to for a while was the Apache Camel project.   I remember it was last year.  It was a camel-fop component.

This component uses the Apache FOP project to render messages into variety of output formats such as PDF, PostScript, RTF, PNG etc.

Camel-fop has only a producer, which expects messages containing XML data in XSL-FO format in the body. Assuming that your data and representation are separate, xsl-fo can be generated from xml data and xslt template, or instead using freemarker or velocity templates and passing the data with message headers.

Once the content is ready in the message body, camel-fop will transform it to the output format specified in the endpoint URL or message header.

It is also possible to set some metadata for each document (like producer, author, creation date, resolution...) or encrypt the document with password.

Additionally it allows you to override the default fop configuration file by specifying a new userConfig location in the endpoint URL. With a custom configuration you can control fop's rendering behavior and help it find its resources.

Here is an example route that creates PDFs from xml data and xslt template:

      .from("file:source/data/xml")

          .to("xslt:xslt/template.xsl")

          .to("fop:application/pdf")

          .to("file:target/data");