"Boule.obtenirCouleur()" becomes "Boule.couleur()".
Rename variables.
"Case.invalideCase()" becomes "Case.invalider()"
"Case.affecteBoule()" becomes "Case.placerBoule()"
"Case.videCase" becomes "Case.vider"
Use "placerBoule" rather than "affecteBoule".
Add TODO (EnumPosition.java)
Use custom toString methods to simplify Case.obtenirStatusCouleur()
Clean comments.
Inline some useless methods.
Add serialVersionUID.
Rename internal method.