Uses of Interface
org.bukkit.boss.BossBar

Packages that use BossBar 
Package Description
org.bukkit
The root package of the Bukkit API, contains generalized API classes.
org.bukkit.boss
Classes concerning the creation of boss bars that appear at the top of the player's screen.
org.bukkit.entity
Interfaces for non-voxel objects that can exist in a world, including all players, monsters, projectiles, etc.