UseCases classes from Haseeb.java

package entities;

/** Represents a content item. */
abstract class Content { 
	UUID id;
}

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package domain.usecases;

public interface GetLobbyContent {
    List<Content> get();
}

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package domain;

/**
Business use case: show the user a list of content in the lobby
*/
public class GetLobbyContentUseCase implements domain.usercases.GetLobbyContent {
	private ContentRepository repository;

	public GetLobbyContentUseCase(ContentRepository repository) {
		this.repository = repository;
	}

	public List<Content> get() throws Exception {
		return repository.getLobbyContent();
	}
}

/** Collects together provider methods for content-related data  */
public interface ContentRepository {
	/** Returns a page of lobby content */
	public List<Content> getLobbyContent();

	/** Returns a page of video content */
	public List<Content> getVideoContent();
}

public class GetLobbyContentUseCaseTest {
	@InjectMocks
	GetLobbyContentUseCase testSubject;

	@Mock
	ContentRepository repository;

	@Before
	public void setup() {
		initMocks(this);
	}

	@Test
	public void execute_returnsContent() {
		//GIVEN
		when(repository.getLobbyContent()).thenReturn(mockData);
		
		//WHEN
		List<Content> result = testSubject.execute();
		
		//THEN
		assertThat(result, is(mockData));
	}

	@Test (expected = Exception.class)
	public void execute_whenRepositoryThrowsException_throwsException() {
		//GIVEN
		when(repository.getLobbyContent()).thenThrow(mockException);
		
		//WHEN
		testSubject.execute();
	}
}

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package ui;

class LoaderPresenter {
	@Inject LoaderView view;
	@Inject domain.usecases.GetLobbyContent useCase;
	@Inject Dispatcher dispatcher;

	public void loadData(){
		view.showLoader();
		
		dispatcher.invoke(
			()    -> useCase.get();
			()    -> view.hideLoader());
	}
}

class LobbyPresenter {
	@Inject LobbyView view;
	@Inject domain.usecases.GetLobbyContent useCase;
	@Inject Dispatcher dispatcher;

	public void displayLobbyContent() {
		dispatcher.invoke(
			()    -> useCase.get(),
			items -> view.showItems(items));
	}
}