$ sudo apt-get update
$ sudo apt-get install libpdfbox-java 

libpdfbox-java is installed in your system.

Make ensure the libpdfbox-java package were installed using the commands given below,

$ sudo dpkg-query -l | grep libpdfbox-java *

You will get with libpdfbox-java package name, version, architecture and description in a table

libpdfbox-java package basic information: