Spring继承自动装配注释

Question

For inheritance I see examples using XML Definition. I had a doubt using Autowire and Annotations.

I have

@Component
class A{

}

@Component
class B extends A{

}

class TestClass{
    @Autowire
    A aObj;
}

So I believe this will inject Object of Class A. Correct ? Also If I make my class A as abstract, it will inject Class B object. Correct ?

Also it would be good if someone can give me a link to example for this.

Answer 1

I tried the code and got the results as follows.

For above it throws NoUniqueBeanException.

2. If I make Class A as abstract it injects Class B Bean and works fine.

3. If I don't want to make class A as abstract I need to Use Qualifiers as follows

    @Component(value="aBean") class A{ } @Component(value="bBean") class B extends A{ } class TestClass{ @Autowire @Qualifier(value="aBean") A aObj; } 

   This injects Class A bean.