CODEWITHSUNDEEP
javaspringspring-annotations
Umesh Awasthi
Umesh Awasthi

Reputation: 23587

Using javax.inject.Provider in place of <lookup-method>

I am trying to see how i can use javax.inject.Provider in place of Spring <lookup-method>. here is my code

public abstract class MyAbstractClass<Source,Target>{
   @Autowired
    private Provider<Target> targetBean;

    protected abstract Target createTarget();
    public Provider<Target> getTargetBean() {
          return this.targetBean;
   }

}

public class MyClass extends MyAbstractClass<ObjectA, ObjectB>{

  @Override
   protected ObjectB createTarget()
    {
      return this.targetBean.get();  
    }
}

But when i am running this code, i am getting following exception

org.springframework.beans.factory.NoSuchBeanDefinitionException: No unique bean of type [java.lang.Object] is defined: expected single matching bean but found // list of all beans

I know, my understanding of Provider is not right, but my question is, do i need to provide 

  @Autowired
  private Provider<Target> targetBean;

In each implementation class or is there something i am doing totally wrong? I was assuming that since i am passing type of object to Abstract class, Provider will able to find type of bean which is being requested.

Upvotes: 1

Views: 1031

Answers (1)

diegomtassis
diegomtassis

Reputation: 3667

@Component
@Scope("prototype")
public class Prototype
    {
    }

@Component
public class Singleton
    {    
    @Autowired
    Provider<Prototype> prototype;

    public Prototype createPrototype()
        {
        return this.prototype.get();
        }
    }

@Configuration
@ComponentScan
public class Factory
    {
    // The ComponentScan does the job
    }

@RunWith(SpringJUnit4ClassRunner.class)
@ContextConfiguration(loader = AnnotationConfigContextLoader.class, classes = { Factory.class })
public class SingletonPrototypeTest
    {    
    @Autowired
    Singleton singleton;

    @Test
    public void testFoo()
        {
        Assert.assertTrue(this.singleton.createPrototype() != this.singleton.createPrototype());
        }
    }

Upvotes: 1

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