I think it is both. This answer begins with an assumption that the justice with which God is primarily concerned is distributive justice. In popular discourse, justice is often associated with retributive justice in legal systems--punishment to make amends for wrongs already committed. While the Law of Moses certainly seems to have an emphasis on this kind of justice, I think the Prophets and Jesus Christ were much more concerned with making things fair in the first place, so that no one is left out. Just actions and social orders both exemplify and create righteousness. By the same token, Godly righteousness inspires persons to do justly in the first place.