org.jbox2d.collision
Classes 
AABB
Collision
Collision.ClipVertex
ContactID
Distance
Distance.DistanceProxy
Distance.SimplexCache
DistanceInput
DistanceOutput
Manifold
ManifoldPoint
RayCastInput
RayCastOutput
TimeOfImpact
TimeOfImpact.TOIInput
TimeOfImpact.TOIOutput
WorldManifold
Enums 
Collision.PointState
ContactID.Type
Manifold.ManifoldType
TimeOfImpact.TOIOutputState