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Can't achieve dependency injection oustide a controller in Spring Booot

I am new at spring MVC framework and i am currently working in a web application that uses a session scoped bean to control some data flow.
I can access these beans in my application context using #Autowired annotation without any problem in the controllers. The problem comes when I use a class in service layer that does not have any request mapping (#RequestMapping, #GetMapping nor #PostMapping) annotation.
When I try to access the application context directly or using #Autowired or even the #Resource annotation the bean has a null value.
I have a configuration class as follow:
#Configuration
#EnableAspectJAutoProxy
#EnableJpaRepositories(repositoryFactoryBeanClass = EnversRevisionRepositoryFactoryBean.class, basePackages = "com.quantumx.nitididea.NITIDideaweb.repository")
public class AppConfig implements WebMvcConfigurer {
#Bean (name = "lastTemplate")
#SessionScope
public LastTemplate getlastTemplate() {
return new LastTemplate();
}
//Some extra code
}
The POJO class is defined as :
public class LastTemplate {
private Integer lastId;
public LastTemplate(){
}
public Integer getLastId() {
return lastId;
}
public void setLastId(Integer lastId) {
this.lastId = lastId;
}
}
The I have a Test class that is annotated as service and does not have any request mapping annotated method:
//#Controller
#Service
public class Test {
// #Autowired
// private ApplicationContext context;
// #Autowired
#Resource(name = "lastTemplate")
public LastTemplate lastTemplate;
// #Autowired
// public void setLastTemplate(LastTemplate lastTemplate) {
// this.lastTemplate = lastTemplate;
// }
public Test() {
}
// #RequestMapping("/test")
public String testing() {
// TemplateForma last = (TemplateForma) context.getBean("lastInsertedTemplate");
// System.out.println(last);
System.out.println(lastTemplate);
// System.out.println(context.containsBean("lastTemplate"));
// System.out.println(context.getBean("lastTemplate"));
System.out.println("Testing complete");
return "Exit from testing method";
// return "/Messages/Success";
}
}
As you can see, there is a lot of commented code to show all the ways i have been trying to access my application context, using an Application context dependency, autowiring, declaring a resource and trying with a request mapping. The bean is null if no controller annotation and request mapping method is used and throws a java null pointer exception when I use the context getBean() methods.
Finally I just test my class in a controller that i have in my app:
#RequestMapping("/all")
public String showAll(Model model) {
Test test = new Test();
test.testing();
return "/Administrator/test";
}
Worth to mention that I also tried to change the scope of the bean to a Application scope and singleton, but it not worked. How can access my application context in a service class without mapping a request via controller?

Worth to mention that I also tried to change the scope of the bean to a Application scope and singleton, but it not worked
It should have worked in this case.
How can access my application context in a service class without mapping a request via controller?
Try one of these :-
#Autowired private ApplicationContext appContext;
OR
Implement ApplicationContextAware interface in the class where you want to access it.
Edit:
If you still want to access ApplicationContext from non spring managed class. Here is the link to article which shows how it can be achieved.
This page gives an example to get spring application context object with in non spring managed classes as well

What worked for me is that session scoped bean had to be removed in the application configuration declaration and moved to the POJO definition as follows:
#Component
#SessionScope
public class LastTemplate {
private Integer lastId;
public LastTemplate(){
}
public Integer getLastId() {
return lastId;
}
public void setLastId(Integer lastId) {
this.lastId = lastId;
}
}
The I just call the bean using #Autowired annotation.

Spring boot inject bean at runtime based on request endpoint/request param

I have an interface that has two implementations, and I'd like to conditionally inject either of the two implementations in a spring boot service.
The point is that the eligible implementation should be picked up based on the request message (JSON mapped to a POJO).
My searches leaded me to implement a FactoryBean to control selecting between those two implementations, and to keep the factory telling spring that the beans are not singleton (by returning false for the isSingleton method).
But if this is the right way, I am still not sure how to get the request message to check it and return the right bean.
Can you please tell me if I am on the right track for what I am trying to attain?
=============
UPDATE
I do not want to pollute my code and deal with managing the relation between my service and the dependencies' implementation in the service.
Considering that I will need to deal with more implementations in the future, I need my service to care only about its responsibility.
I need my service to have only one reference of the generic interface and deal with it in an abstracted way.
I need to find a spring-based way to choose the right implementation for each request based on a condition that is derived from the request itself, and inject it in the service.

One option is to inject both beans and conditionally pick the required bean. You can autowire classes implementing same interface into a Map.
Following example uses a factory class to hide the conditional check.
#Component("type1")
public class Type1 implements SomeInterface{}
#Component("type2")
public class Type2 implements SomeInterface{}
#Component
public class MyTypeFactory {
#Autowired
private Map<String, SomeInterface> typesMap;
public SomeInterface getInstance(String condition){
return typesMap.get(condition);
}
}
#Component
public class MyService {
#Autowired
private MyTypeFactory factory;
public void method(String input){
factory.getInstance(input).callRequiredMethod();
}
}

You could #Autowire both beans in the controller and decided based on the request which one to return.
Consider the below interface:
public interface MyInterface { ... }
Sample config:
#Configuration
public class MyConfig {
#Bean("first")
public MyInterface firstBean() { ... }
#Bean("second")
public MyInterface secondBean() { ... }
}
Sample controller:
#RestController
public class MyController {
#Autowire
#Qualifier("first")
public MyInterface first;
#Autowire
#Qualifier("second")
public MyInterface second;
#GetMapping
public MyInterface doStuff(#RequestBody body) {
if(shouldReturnFirst(body)){
return first;
} else {
return second;
}
}
}
Note that you should most likely not do it this way though, but have a single service, say MyService that should implement this logic for you.
#Component
public class MyService {
public MyInterface doStuff(body) {
if(shouldReturnFirst(body)){
// build your response here
} else {
// build your response here
}
}
}
And just delegate to the service from the controller
#GetMapping
public MyInterface doStuff(#RequestBody body) {
return myService.doStuff(body);
}

Spring has a concept of Conditional Bean...
Have a look here https://www.intertech.com/Blog/spring-4-conditional-bean-configuration/

Loading Beans based on hostname

I am writing services in Spring boot that get their configurations from Spring cloud. These services are multi-tenant and the tenant is based on the host name.
what I have now is
public class MyController {
#Autowired
public MyController(MyServiceFactory factory) {
...
}
#RequestMapping("some/path/{id}")
ResponseEntity<SomeEntity> getSomeEntity(#RequestHeader header, #PathVariable id) {
return factory.getMyService(header).handle(id);
}
}
where MyServiceFactory looks something like...
public class MyServiceFactory {
private final HashMap<String, MyService> serviceRegistry = new HashMap<>();
public MyService getMyService(String key) {
return serviceRegistry.get(key);
}
MyServiceFactory withService(String key, MyService service) {
this.serviceRegistry.put(key, service);
return this;
}
}
then in a configuration file
#Configuration
public ServiceFactoryConfiguration {
#Bean
public MyServiceFactory getMyServiceFactory() {
return new MyServiceFactory()
.withService("client1", new MyService1())
.withService("client2", new MyService2());
}
}
While what I have now works, I don't like that I need to create a factory for every dependency my controller may have. I'd like to have my code look something like this...
public class MyController {
#Autowired
public MyController(MyService service) {
...
}
#RequestMapping("some/path/{id}")
ResponseEntity<SomeEntity> getSomeEntity(#PathVariable id) {
return service.handle(id);
}
}
with a configuration file like
#Configuration
public class MyServiceConfiguration() {
#Bean
#Qualifier("Client1")
public MyService getMyService1() {
return new MyService1();
}
#Bean
#Qualifier("Client2")
public MyService getMyService2() {
return new MyService2();
}
}
I can get the code that I want to write if I use a profile at application start up. But I want to have lots of different DNS records pointing to the same (pool of) instance(s) and have an instance be able to handle requests for different clients. I want to be able to swap out profiles on a per request basis.
Is this possible to do?

Spring profiles would not help here, you would need one application context per client, and that seems not what you want.
Instead you could use scoped beans.
Create your client dependent beans with scope 'client' :
#Bean
#Scope(value="client",proxyMode = ScopedProxyMode.INTERFACES)
#Primary
MyService myService(){
//does not really matter, which instance you create here
//the scope will create the real instance
//may be you can even return null, did not try that.
return new MyServiceDummy();
}
There will be at least 3 beans of type MyService : the scoped one, and one for each client. The annotation #Primary tells spring to always use the scoped bean for injection.
Create a scope :
public class ClientScope implements Scope {
#Autowired
BeanFactory beanFactory;
Object get(String name, ObjectFactory<?> objectFactory){
//we do not use the objectFactory here, instead the beanFactory
//you somehow have to know which client is the current
//from the config, current request, session, or ThreadLocal..
String client=findCurrentClient(..);
//client now is something like 'Client1'
//check if your cache (HashMap) contains an instance with
//BeanName = name for the client, if true, return that
..
//if not, create a new instance of the bean with the given name
//for the current client. Easiest way using a naming convention
String clientBeanName=client+'.'+name;
Object clientBean=BeanFactory.getBean(clientBeanName);
//put in cache ...
return clientBean;
};
}
And your client specific beans are configured like this :
#Bean('Client1.myService')
public MyService getMyService1() {
return new MyService1();
}
#Bean('Client2.myService')
public MyService getMyService2() {
return new MyService2();
}
Did not test it but used it in my projects. Should work.
tutorial spring custom scope

JaxRS: REST URL not reachable. Misconfigured?

I try to build up a simple EJB-project on JBoss Wildfly.
I want a stateless EJB to be a JAX-RS resource class. This REST-service should simply return the Person-entities saved in the database.
EJB-Code:
#Stateless
#Path("/person")
public class PersonServiceBean {
#PersistenceContext EntityManager em;
#GET
#Produces(MediaType.APPLICATION_JSON)
public List<Person> getAllPersons(){
return em.createQuery("FROM " + Person.class.getName()).getResultList();
}
}
I read I need a subclass of Application with ApplicationPath-annotation
#ApplicationPath("/rest")
public class JaxRsApplication extends Application {
#Override
public Set<Class<?>> getClasses() {
return new HashSet<Class<?>>(Arrays.asList(PersonServiceBean.class));
}
}
But still I get 404 at 'localhost:8080/rest/person'.
Did I miss to configure something?
I would be really thankful for help!

The problem is that the Rest Resource must be in a WAR and not in a EJB project.

Cannot use #EJB to instantiate my object in the WAR application

I am learning Java EE and JSP. I have created an Enterprise Application project in NetBeans.
I have the EJB project where all beans are and a WAR project where all web/client stuff is.
My problem is that the annotation #EJB does not instantiate my Bean in the WAR application. Can I use #EJB outside the EJB application?
In the EJB project, I have these files:
CustomerRemote.java
#Remote
public interface CustomerRemote {
public Customer createCustomer();
public Customer getCustomer(int customerId);
public void removeCustomer();
}
CustomerBean.java
#Stateless
public class CustomerBean implements CustomerRemote {
#PersistenceContext(unitName="testPU")
private EntityManager entityManager;
#Override
public Customer createCustomer() {
throw new UnsupportedOperationException("Not supported yet.");
}
#Override
public void removeCustomer() {
}
#Override
public Customer getCustomer(int customerId) {
throw new UnsupportedOperationException("Not supported yet.");
}
}
In the WAR project, I have a file that my JSP page uses to communicate with the EJB stuff. The problem is that the CustomerRemote object is never instantiated. #EJB annotation does not seem to work because customerRemote always is null. But when instantiating it with the lookup method, it works! So why does not #EJB work?
public class CustomerProxyBean {
#EJB
private CustomerRemote customerRemote;
public CustomerProxyBean() {
// try {
// InitialContext context = new InitialContext();
// customerRemote = (CustomerRemote)context.lookup("java:app/SimpleShop-ejb/CustomerBean");
//
// } catch (NamingException ex) {
// Logger.getLogger(CustomerProxyBean.class.getName()).log(Level.SEVERE, null, ex);
// }
}

#EJB annotation will work only in cases where your class is container-managed, that is EJB, servlet, JSP... In your case you put it into plain old Java object (POJO) so injection will not work, as you have experienced. Write your CustomerProxyBean as a stateless session bean, and you'll see the change.
Alternatively, if you want to avoid JNDI for some reason, you can use CDI and #Inject annotation to inject EJB and achieve wished behaviour, even in POJO:
#Inject
private CustomerRemote customerRemote;