CODEWITHSUNDEEP
javaspring
membersound
membersound

Reputation: 86657

Bean definition inheritance with annotations?

Is it possible to achieve the same bean inheritance using annotation based configuration (@Bean etc)?

<bean id="inheritedTestBean" abstract="true"
        class="org.springframework.beans.TestBean">
    <property name="name" value="parent"/>
    <property name="age" value="1"/>
</bean>

<bean id="inheritsWithDifferentClass"
        class="org.springframework.beans.DerivedTestBean"
        parent="inheritedTestBean" init-method="initialize">
    <property name="name" value="override"/>
    <!-- the age property value of 1 will be inherited from parent -->
</bean>

http://docs.spring.io/spring/docs/4.1.0.BUILD-SNAPSHOT/spring-framework-reference/htmlsingle/#beans-child-bean-definitions

Upvotes: 19

Views: 10220

Answers (1)

Stephane Nicoll
Stephane Nicoll

Reputation: 33091

There is no notion of abstract bean in java config because the java language already has everything you need. Don't forget that abstract beans are not exposed in the context at all, it's some kind of template.

You could rewrite your code above as follows:

@Configuration
public class Config {

    @Bean
    public DerivedTestBean() {
        DerivedTestBean bean = new DerivedTestBean();
        initTestBean(bean);
        bean.setName("override");
        return bean;
    }

    private void initTestBean(TestBean testBean) {
        testBean.setName("parent");
        testBean.setAge(1);
    } 
}

If the initTestBean should be shared, you can just as well make it public and inject Config in other places if you need to.

Upvotes: 29

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