On my first spring mvc project, I am trying to get a better understanding of the directory structure with this project and why it is done as such
I get what goes in ‘controllers’ and ‘views’ directory, but am unsure of the others. If I look at the .java file in beans and commands, they look the same to me – no difference in annotations between the two, so why can’t the 2 directories be combined into one?
What goes into services?
The mappers looks like it is for mapping with a database for an OR/M object
Not sure of resolvers directory
Is this standard way of organizing spring mvc projects?

Every project has its structure according to the style of organization/user. The structures abide the standards set down by the organization. So they vary from one to another. A MVC project can be broadly categoried into
The above are the main three. Then there might be other folders like
In the context of spring, any class marked with an annotation inheriting from
@Componentis a bean, so the structure that you have mentioned in the question could have been made keeping that in mind but isn’t being used correctly.The resolvers folder might host View Resolvers. This is, again, just a guess. Depends entirely on you.
You could look into maven’s spring archetype and the way it organizes a spring project to get a view of how the creators of Spring organize a project.