$ sudo apt-get update
$ sudo apt-get install libjava-gmsh2 

libjava-gmsh2 is installed in your system.

Make ensure the libjava-gmsh2 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libjava-gmsh2 *

You will get with libjava-gmsh2 package name, version, architecture and description in a table

libjava-gmsh2 package basic information: