spring framework : expected single matching bean but found 2 - spring

This super class DAO:
public class CrudDAO{
}
This child class:
#Repository
public class JnsTimeDao extends CrudDAO {
}
#Repository
public class BatchDAO extends CrudDAO {
}
this super service class
#Transactional(readOnly = true)
public abstract class CrudService<D extends CrudDAO> {
#Autowired
protected D dao;
}
startup error:
org.springframework.beans.factory.NoUniqueBeanDefinitionException: No
qualifying bean of type [com.gp.dao.CrudDAO] is defined: expected
single matching bean but found 2: batchDAO,jnsTimeDao

There are 2 beans of type CrudDAO. So, Spring won't be able to understand which bean to inject. Can be solved as follows
#Repository("jnsTimeDao")
public class JnsTimeDao extends CrudDAO {
}
#Repository("batchDao")
public class BatchDAO extends CrudDAO {
}
While injecting use #Qualifier
#Transactional(readOnly = true)
public abstract class CrudService<D extends CrudDAO> {
#Autowired
#Qualifier("batchDao")
protected D dao;
}

Related

Why can't #Autowired a JPA repository - Spring boot + JPA

I'm giving this error:
Parameter 0 of constructor in x.microservice.module.business.application.BusinessCreator required a bean of type 'x.microservice.module.business.infrastructure.HibernateJpaRepository' that could not be found.
The injection point has the following annotations:
- #org.springframework.beans.factory.annotation.Autowired(required=false)
Action:
Consider defining a bean of type 'x.microservice.module.business.infrastructure.HibernateJpaRepository' in your configuration.
The controller:
#Slf4j
#RestController
public final class BusinessPostController {
#Autowired
private BusinessCreator creator;
#PostMapping(value = "/business")
public ResponseEntity create(#RequestBody Request request){
BusinessCreatorDto businessCreatorDto = new BusinessCreatorDto(IdentifierEpoch.generate(),request.getName());
return ResponseEntity.ok(
creator.create(businessCreatorDto)
);
}
}
The Application Layer:
#AllArgsConstructor
#Service
public class BusinessCreator {
#Autowired
private HibernateJpaRepository repository;
public BusinessResponse create(BusinessCreatorDto dto){
Business business = new Business(dto.getId(), dto.getName());
repository.save(business);
return BusinessResponse.fromAggregate(business);
}
}
In the Infrastructure layer
#Repository
public abstract class HibernateJpaRepository implements JpaRepository<Business, Long> {
}
The boot Application:
#EnableJpaRepositories
#SpringBootApplication
public class MicroserviceApplication {
public static void main(String[] args) {
SpringApplication.run(MicroserviceApplication.class, args);
}
}
All dependencies are resolved and the others classes I believe that are irrellevant.
Any suggestions? Thank you very much
Probably, the error cause is HibernateJpaRepository - it has to be an interface that extends JpaRepository.
You could write your own Repository in a interface:
#Repository
public interface HibernateJpaRepository extends JpaRepository < Business, Long > {
}
Then your Class:
#AllArgsConstructor
#Service
public class BusinessCreator {
#Autowired
private HibernateJpaRepository repository;
public BusinessResponse create(BusinessCreatorDto dto){
Business business = new Business(dto.getId(), dto.getName());
repository.save(business);
return BusinessResponse.fromAggregate(business);
}
}

Spring injection for bean with generic wildcard

I have the following:
public abstract class ReportGenerationStrategy<T extends ReportParameter> {
public abstract void generate(T reportParameter) throws IOException;
}
The subclasses:
#Component
#AllArgsConstructor
public class DeferredRevenueReportGenerationStrategy extends ReportGenerationStrategy<DeferredRevenueReportParameter> {
}
#Component
#AllArgsConstructor
public class OffBalanceExposureReportGenerationStrategy extends ReportGenerationStrategy<OffBalanceExposureReportParameter> {
}
I am creating a map with the subclasses:
#Bean
public Map<ReportType, ReportGenerationStrategy<? extends ReportParameter>> generationStrategies(
#Qualifier("deferredRevenueReportGenerationStrategy") final ReportGenerationStrategy<? extends ReportParameter> deferredRevenue,
#Qualifier("offBalanceExposureReportGenerationStrategy") final ReportGenerationStrategy<? extends ReportParameter> offBalanceExposure
)
{
return ImmutableMap.of(
ReportType.DEFERRED_REVENUE, deferredRevenue,
ReportType.OFF_BALANCE_EXPOSURE, offBalanceExposure
);
}
And trying to inject the map as following:
#AllArgsConstructor
#Slf4j
public class ReportApplicationServices {
private final Map<ReportType, ReportGenerationStrategy<ReportParameter>> generationStrategies; //Empty map injected
}
But I receive an empty map on the field...
Why is this happening?
I believe you missed to use #Autowire annotation on the private final Map that you have declared.
Hope this helps and solves the issue.

Spring Boot cannot autowired component with abstract and interface

In my Spring Boot 2.0.2 application I am trying to inject a component herited from abstract class which implements an interface and it doesn't work.
Code :
Component Abstract : (Do I need to put #Component ?)
package app.project.service;
#Component
public abstract class AbstractStepService implements IStepService {
protected final void addTask() {
...
}
#Override
public StepDataDto launch() throws StepException {
...
}
}
Interface :
package app.project.service;
public interface IStepService {
StepDataDto launch() throws StepException;
}
package app.project.service;
Component :
#Component
public class CStepServiceImpl extends AbstractStepService implements IStepService {
#PostConstruct
private void defineTasks() {
}
}
package app.project.service;
Junit Test :
#RunWith(SpringRunner.class)
#SpringBootTest
public class CStepServiceTest {
#Autowired
#Qualifier("cStepServiceImpl")
private IStepService service;
}
package app.project;
Application :
#SpringBootApplication
#ComponentScan(basePackages ={"app.project.service"})
public class MyApplication {}
Error message when launching my Junit test :
Caused by: org.springframework.beans.factory.NoSuchBeanDefinitionException: No qualifying bean of type 'app.project.service.IStepService' available: expected at least 1 bean which qualifies as autowire candidate. Dependency annotations: {#org.springframework.beans.factory.annotation.Autowired(required=true), #org.springframework.beans.factory.annotation.Qualifier(value=cStepServiceImpl)}
Any idea ?
Thanks
Change your declaration like this
#Autowired
#Qualifier("CStepServiceImpl")
private IStepService service;
or
#Autowired
private IStepService CStepServiceImpl;
That should work. The bean name created automatically by spring has CStepServiceImpl name.
You can also name your bean like this
#Component(value = "myName")
public class CStepServiceImpl extends AbstractStepService implements IStepService {
}
and use myName during Autowiring.

How to extend #Service with spring,NoUniqueBeanDefinitionException

Here is a sample class below
#Service("testService")
public class TestService {
public String something() {
return "abc";
}
}
I want to extend the class and let the container know that it needs to pick up my extended class from now.
#Service("extendedTestService")
public class ExtendedTestServiceMock extends TestService {
#override
public String something() {
return "xyz";
}
}
Test class
public class TestClass extends SpringTest {
#Autowired
#Qualifier("extendedTestService")
private ExtendedTestServiceMock testService;
public void testMethod(){
......
}
}
Caused by: org.springframework.beans.factory.NoUniqueBeanDefinitionException: No qualifying bean of type [TestService] is defined: expected single matching bean but found 2: ExtendedTestServiceMock,testService
at org.springframework.beans.factory.support.DefaultListableBeanFactory.doResolveDependency(DefaultListableBeanFactory.java:865) ~[spring-beans-3.2.8.RELEASE.jar:3.2.8.RELEASE]
at org.springframework.beans.factory.support.DefaultListableBeanFactory.resolveDependency(DefaultListableBeanFactory.java:770) ~[spring-beans-3.2.8.RELEASE.jar:3.2.8.RELEASE]
at org.springframework.beans.factory.annotation.AutowiredAnnotationBeanPostProcessor$AutowiredFieldElement.inject(AutowiredAnnotationBeanPostProcessor.java:489) ~[spring-beans-3.2.8.RELEASE.jar:3.2.8.RELEASE]
... 91 common frames omitted
How to resolve it?
You haven't defined a bean of type ExtendedTestService.
You have only defined a bean of type ExtendedTestServiceMock.
Try this:
#Autowired
#Qualifier("extendedTestService")
private TestService testService;
The solution is use a #service anotation, you should inject the service like this:
#Autowired
private TestService testService;
And then you can use the methods of TestService

Spring Inject Collection From Superclass

I have the following scenario:
class Super{
private List<String> someStringsThatWillBeDifferentForEveryInstancePerDerivedType;
}
#Component
class Derived1 extends Super{
#Autowired
private String name;
}
#Component
class Derived2 extends Super{
#Autowired
private Long configId;
}
I have a different List defined as Spring bean in xml for each derived class…call them listForDerived1 and listForDerived2. How can I wire these lists into my derived classes? I attempted constructor injection but I can't seem to find any luck injecting both the collection and the other deps.
You can use constructor injection with #Qualifier.
class Super {
private List<String> someStrings;
public Super(private List<String> someStrings) {
this.someStrings = someStrings;
}
}
#Component
class Derived1 extends Super {
#Autowired
public Derived1(#Qualifier("listForDerived1") List<String> listForDerived1, OtherBean bean) {
super(listForDerived1);
}
}
#Component
class Derived2 extends Super {
#Autowired
public Derived1(#Qualifier("listForDerived2") List<String> listForDerived1, OtherBean bean) {
super(listForDerived2);
}
}
Also see official Spring doc: http://docs.spring.io/spring/docs/current/spring-framework-reference/htmlsingle/#beans-autowired-annotation-qualifiers

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