Spring MVC - How to create a proper Service layer? - spring-mvc

I'm using SpringBoot and I am trying to create a service layer for my web application but i cant make it work.
My classes look like this
ServiceFactory
#Service
public class ServiceFactory {
#Autowired
public static EncuestaService getEncuestaService()
{
return new EncuestaServiceImpl();
}
}
EncuestaService
public interface EncuestaService {
void crearEncuesta(Encuesta encuesta, Map<String,String> parametros);
}
EncuestaServiceImpl
#Service
public class EncuestaServiceImpl implements EncuestaService {
#Override
public void crearEncuesta(Encuesta encuesta, Map<String, String> parametros) {
CrearEncuesta nueva = new CrearEncuesta(encuesta,parametros);
nueva.execute();
}
}
CrearEncuesta
#Service
public class CrearEncuesta {
private Encuesta encuesta;
private Map<String,String> parametros;
#Autowired
private RespuestasRepository respuestasRepository;
#Autowired
private EncuestasRepository encuestasRepository;
public CrearEncuesta(Encuesta encuesta, Map<String,String> parametros) {
super();
this.encuesta = encuesta;
this.parametros = parametros;
}
public void execute()
{
encuestasRepository.save(encuesta);
}
}
Everytime I call ServiceFactory.getEncuestasService().crearEncuesta() from any Controller it returns me a NullPointerException.
From what I have been reading I should not be creating a new EncuestsaServiceImpl() in my ServiceFactory but I don't really know the correct way to do so. I would appreciate if anyone could help me out :P.
Edit:
#SpringBootApplication
public class Application {
public static void main(String[] args) {
SpringApplication.run(Application.class, args);
}
Controller
#Controller
public class EncuestaController {
#RequestMapping(value ="registrarEncuesta", method = RequestMethod.POST)
private String formularioEncuesta(#Valid #ModelAttribute("formEncuesta") EncuestaForm formEncuesta, BindingResult bindingResult,#RequestParam Map<String,String> allRequestParams)
{
if (bindingResult.hasErrors()) {
return "nuevaEncuesta";
}
try {
Encuesta nueva = formEncuesta.toEncuesta();
ServiceFactory.getEncuestaService().crearEncuesta(nueva,allRequestParams);
} catch (DataIntegrityViolationException e) {
return "nuevaEncuesta";
}
return "redirect:/encuestas";
}
}

You will have to read a little bit more about dependency injection. The central principle in Spring Framework is dependency injection which should be used to avoid referencing beans (service implementations, repository implementations etc...) statically. Spring container also servers as a bean factory that will instantiate and inject (autowire) implementations to beans that need them.
Because Spring will instantiate service interface implementations for you, you don't need ServiceFactory. In your controller you need to add a reference (a field) to EncuestaService and annotate it as Autowired and Spring will wire in the implementation. And then you can just use it in your controller.
#Controller
public class EncuestaController {
#Autowired
EncuestaService encuestaService;
#RequestMapping(value ="registrarEncuesta", method = RequestMethod.POST)
private String formularioEncuesta(#Valid #ModelAttribute("formEncuesta") EncuestaForm formEncuesta, BindingResult bindingResult,#RequestParam Map<String,String> allRequestParams)
{
if (bindingResult.hasErrors()) {
return "nuevaEncuesta";
}
try {
Encuesta nueva = formEncuesta.toEncuesta();
encuestaService.crearEncuesta(nueva,allRequestParams);
} catch (DataIntegrityViolationException e) {
return "nuevaEncuesta";
}
return "redirect:/encuestas";
}
}

Related

Spring redis unable to autowire repository

I'm using custom crudrespository to persist data in redis. However, I'm unable to autowire custom repository.
All the configuration seems correct and redis is running on my local.
import org.springframework.data.repository.CrudRepository;
import org.springframework.stereotype.Repository;
#Repository
public interface CustomRepository extends CrudRepository<String,
Long> {
String get(String key);
void put(String key, String value);
}
//////////
public class StorageServiceImpl implements IStorageService {
#Autowired
private CustomRepository respository;
#Override
public void saveParameter() {
this.respository.put("key1","value1");
}
#Override
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return this.respository.get("key1");
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/////
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void saveParameter();
String getParameter();
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///////
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public static void main(String[] args){
SpringApplication.run(ApplicationConfiguration.class, args);
new StorageServiceImpl().saveParameter();
System.out.println(new StorageServiceImpl().getParameter());
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When I try running this application using gradle bootRun, I get
Exception in thread "main" java.lang.NullPointerException
at com.example.cache.impl.StorageServiceImpl.saveParameter(StorageServiceImpl.java:16)
at com.example.cache.ApplicationConfiguration.main(ApplicationConfiguration.java:17)
Not sure what's wrong?
You can't use new on any bean, you need to #Autowire it. The annotations only work with spring managed beans at every level.
Add a new bean with a a storage service and a method that makes your call after it is created.
Also, I can't remember if the spring-boot creates the bean if there is only one implementation but I believe your StorageServiceImpl needs the #Service annotation, not the interface.
Delete this from your ApplicationConfiguration class.
new StorageServiceImpl().saveParameter();
System.out.println(new StorageServiceImpl().getParameter());
Then add this new class.
#Service
public class Startup {
#Autowired
IStorageService storageService;
#PostConstruct
public void init(){
storageService.saveParameter();
System.out.println(storageService().getParameter());
}
}
And you need a config
#Configuration
#EnableRedisRepositories
public class ApplicationConfig {
#Bean
public RedisConnectionFactory connectionFactory() {
return new JedisConnectionFactory();
}
#Bean
public RedisTemplate<?, ?> redisTemplate() {
RedisTemplate<byte[], byte[]> template = new RedisTemplate<byte[], byte[]>();
return template;
}
}

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All classes that inherit from controller have already inserted the dependencies, but I do not know how to inject those who do not inherit from contoller.
in the example below the SendEmailAndLog() method waits for the ILoggerService interface to be injected. but I do not know how to do this.
public async Task Execute(IJobExecutionContext context)
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SendEmailHelper sendEmailHelper = new SendEmailHelper();
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this task is called the method Application_Start() on Global.asax.cs
I created a constructor to receive this service as a parameter, this is working for the methods within the controllers that call the Class Emailservice. However there are classes that do not inherit from controller so I do not know how to inject.
My Service is:
public interface ILoggerService
{
void Error(ExceptionLogger exception);
void SaveLog();
}
public class LoggerService : ILoggerService
{
private readonly ILoggerRepository loggerRepository;
private readonly IUnitOfWork unitOfWork;
public LoggerService(ILoggerRepository loggerRepository, IUnitOfWork unitOfWork)
{
this.loggerRepository = loggerRepository;
this.unitOfWork = unitOfWork;
}
public void Error(ExceptionLogger exception)
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loggerRepository.Error(exception);
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public void SaveLog()
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unitOfWork.Commit();
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I am trying to write a unit test for the below Assembler but i keep getting Could not find current request via RequestContextHolder. Is this being called from a Spring MVC handler?. I wanted to know how i can mock out the resource creation?
#Component
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public LoginResourceAssembler() {
super(User.class, ResourceSupport.class);
}
#Override
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ResourceSupport resource = new ResourceSupport();
final String id = user.getId();
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Instead of changing from a plain unit test to a IMO integration test (given dependency of the spring framework) you could do something like:
#RunWith(MockitoJUnitRunner.class)
public class LoginResourceAssemblerTest {
#InjectMocks
private LoginResourceAssembler loginResourceAssembler;
#Before
public void setup() {
RequestContextHolder.setRequestAttributes(new ServletRequestAttributes(new MockHttpServletRequest()));
}
#Test
public void testToResource() {
//...
}
}
I was seeing the error Could not find current request via RequestContextHolder. Is this being called from a Spring MVC handler because my test class was annotated with #RunWith(MockitoJUnitRunner.class) and this was not injecting the controller.
To fix this error, i annotated my test case with
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = Application.class)
#WebAppConfiguration
A working test case in my case
#RunWith(SpringJUnit4ClassRunner.class)
#SpringApplicationConfiguration(classes = Application.class)
#WebAppConfiguration
public class LoginResourceAssemblerTest {
#Autowired
private WebApplicationContext context;
private MockMvc mockMvc;
#InjectMocks
private LoginResourceAssembler loginResourceAssembler;
#Before
public void setUp() {
initMocks(this);
this.mockMvc = MockMvcBuilders.webAppContextSetup(this.context).build();
}
#Test
public void testToResource() {
User user = new User();
user.setId("1234");
ResourceSupport resource = loginResourceAssembler.toResource(user);
assertEquals(1,resource.getLinks().size());
assertEquals("accounts",resource.getLinks().get(0).getRel());
assertTrue(resource.getLinks().get(0).getHref().contains("accounts"));
}
}

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I have problem with Abstract Factory pattern implementation on Spring. I am using Spring 3 MVC and Hibernate 3, which works fine if I don't use Abstract Factory Method pattern.
I am not sure what I have to add to the Controller to have access the Factory Class (CategoryFactory).
Is there anything missing in the Controller or bean initiating ?
class SectionsController extends MultiActionController {
/* Do I have to initiate the CategoryFactory here? */
public ModelAndView secList() throws Exception {
CategoryFactory.CategoryType type = CategoryFactory.CategoryType.valueOf("view");
modelMap.addAttribute("sectionList", CategoryFactory.findCategory(type).list(id));
return new ModelAndView("Form", modelMap);
}
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Abstract Factory
public abstract class Category {
public abstract List list(int departId);
}
public class CategoryFactory {
public enum CategoryType { firstclass, secondClass, ... }
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// Create type specific Category implementation
}
}
It shoud be:
class SectionsController extends MultiActionController {
private HibernateTemplate hibernateTemplate;
public void setSessionFactory(SessionFactory sessionFactory) {
this.hibernateTemplate = new HibernateTemplate(sessionFactory);
}
public ModelAndView secList() throws Exception {
CategoryFactory.CategoryType type=CategoryFactory.CategoryType.valueOf("view");
modelMap.addAttribute("sectionList",CategoryFactory.findCategory(type).list(hibernateTemplate,id);
return new ModelAndView("Form", modelMap);
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I am trying to learn TDD/BDD using NUnit and Moq.
The design that I have been following passes a DataService class to my controller to provide access to repositories.
I would like to Mock the DataService class to allow testing of the controllers.
There are lots of examples of mocking a repository passed to the controller but I can't work out how to mock a DataService class in this
scenerio.
Could someone please explain how to implement this?
Here's a sample of the relevant code:
[Test]
public void Can_View_A_Single_Page_Of_Lists()
{
var dataService = new Mock<DataService>();
var controller = new ListsController(dataService);
...
}
namespace Services
{
public class DataService
{
private readonly IKeyedRepository<int, FavList> FavListRepository;
private readonly IUnitOfWork unitOfWork;
public FavListService FavLists { get; private set; }
public DataService(IKeyedRepository<int, FavList> FavListRepository,
IUnitOfWork unitOfWork)
{
this.FavListRepository = FavListRepository;
this.unitOfWork = unitOfWork;
FavLists = new FavListService(FavListRepository);
}
public void Commit()
{
unitOfWork.Commit();
}
}
}
namespace MyListsWebsite.Controllers
{
public class ListsController : Controller
{
private readonly DataService dataService;
public ListsController(DataService dataService)
{
this.dataService = dataService;
}
public ActionResult Index()
{
var myLists = dataService.FavLists.All().ToList();
return View(myLists);
}
}
}
Create an interface like this:
public interface DataService
{
FavListService FavLists { get; }
void Commit();
}
Make your DataService implement this interface and your controller should depend on this interface. Problem solved :)
EDIT: This line of code:
dataService.FavLists.All().ToList();
is breaking the law of demeter and will be a pain to unit test your service. Create a method like AllFavList() on your service instead of all these chain of calls, it will be easier to mock.
EDIT2: How to mock you get property
dataService.SetupGet(d => d.FavLists).Returns(your_variable);

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