Spring @Bean(name =”name”) vs @Bean @Qualifier(“name”)

Yes there is a difference: @Bean("foo") (or @Component("foo")) gives your bean the name “foo” in the Spring Context, whereas @Qualifier("foo") only adds information without changing the name of the bean.

As the bean name is the bean’s unique identifier in the Context, you can only have 1 bean named “foo”, whereas you can have multiple beans with @Qualifier("foo").

Example:

interface TypeOne {}

The following will add a bean with name “beanOne”, automatically generated from the class name.

@Component // explicitly: @Component("beanOne")
class BeanOne implements TypeOne {
}

Same as the following declaration within a @Configuration class:

@Bean // explicitly: @Bean(name = "beanOne")
BeanOne beanOne() { return new BeanOne(); }

The following will add a bean with name “beanTwo” and another with name “beanThree”, with the same qualifier “beanQualifier”:

@Component
@Qualifier("beanQualifier")
class BeanTwo implements TypeOne { }

@Component
@Qualifier("beanQualifier")
class BeanThree implements TypeOne { }

With the above, you can autowire using the qualifier:

@Autowired
@Qualifier("beanQualifier")
Map<String, TypeOne> typeOneMap;

The map will only contain the 2 beans with qualifier “beanQualifier”.

{beanThree=BeanThree@9f674ac, beanTwo=BeanTwo@1da4b3f9}

The other, “beanOne”, has not been wired into the map because it’s not qualified by “beanQualifier”.

Note that the map keys are the bean names that have been automatically generated.