Q:

How to Apply @JsonView only for children of a Object with Spring RestController - serialization?

I have this case: 
public class Project{

    private long id;

    private List<User> users;

    // other properties and getter setter etc
}

public class User{

   @JsonView(MinimalUser.class) 
   private long id;

   @JsonView(MinimalUser.class)
   private String name;

   private ComplexObject anything;

}

Now The RestMethod: 

    @JsonView(MinimalUser.class)
    @GetMapping("/client/{id}")
    public List<Project> findProjectsByClientId(@PathVariable long id) {
        return projectService.findProjectsByClientId(id);
    }

Here I just want a project initialized with the minimal Users objects, but Nothing will be initialized, since there is no "MinimalUser.class" JsonView in my Project, hence it is not initialized.
I don't want to put the @JsonView Annotation, to all my variables in the Project, because this would be overkill.  
How can I tell the Controller to only Apply the @JsonView-Filtering/Serialization to the User(child) of Project? 
Because this call just works fine (I get only the required fields): 

    @JsonView(MinimalUser.class)
    @GetMapping("/minimal")
    public List<User> findAllUsers() {
        return userService.findAllUsers();
    }

A:

If you extend MinimalUser view and apply this new view to entire Project, you can get the following results:
public class MinimalProject extends MinimalUser {}
public class DetailedProject extends MinimalProject {}

// apply view to entire class
@JsonView(MinimalProject.class)
public class Project {
    // keep existing fields as is

    // limit view for project
    @JsonView(DetailedProject.class)
    private String details;
}

// test
ObjectMapper mapper = new ObjectMapper().disable(MapperFeature.DEFAULT_VIEW_INCLUSION);

User u = new User();
u.setId(1);
u.setName("John Doe");
u.setEmail("john@doe.com");
u.setDetails("some details");

System.out.println("user default view: " + mapper.writeValueAsString(u));

System.out.println("user minimal view: " + mapper.writerWithView(MinimalUser.class).writeValueAsString(u));

Project p = new Project();

p.setId(1000);
p.setName("MegaProject");
p.setUsers(Arrays.asList(u));
p.setDetails("Project details: worth $1M");

System.out.println("project default view: " + mapper.writeValueAsString(p));

System.out.println("project minimal view: " + mapper.writerWithView(MinimalProject.class).writeValueAsString(p));

output:
user default view: {"id":1,"name":"John Doe","details":"some details","email":"john@doe.com"}
user minimal view: {"id":1,"name":"John Doe"}
project default view: {"id":1000,"users":[{"id":1,"name":"John Doe","details":"some details","email":"john@doe.com"}],"name":"MegaProject","details":"Project details: worth $1M"}
project minimal view: {"id":1000,"users":[{"id":1,"name":"John Doe"}],"name":"MegaProject"}

