关于打印
https://itextpdf.com/
https://developers.itextpdf.com/examples-itext5
http://search.maven.org/#search%7Cga%7C1%7Cg%3A%22com.itextpdf%22
http://gitlab.itextsupport.com/itext/sandbox/tree/master
https://repo.itextsupport.com/releases/