The OpenHTMLtoPDF project is an attempt to modernize Flying Saucer, the HTML to PDF solution for the JVM.

Here, you can try it out online by entering XHTML in the left pane and viewing a PDF in the right pane.

OpenHTMLtoPDF at Github
Try these examples: hello-world, invoice, cjk, page-features, paginated-table, sidebars, footnotes, menu