This article is stem from the question on stackoverflow. When I read about this question, immediately, I think that it is very useful for me in reality.

Problem

Assuming that you have two configuration in xml file about connections.

<bean id="jedisConnector" class="com.legolas.jedis.JedisConnector" init-method="init" destroy-method="destroy">
    <property name="host" value="${jedis.host}" />
    <property name="port" value="${jedis.port}" />
</bean>

<bean id="jedisConnectorPOD" class="com.legolas.jedis.JedisConnector" init-method="init" destroy-method="destroy">
    <property name="host" value="${jedis.pod.host}" />
    <property name="port" value="${jedis.pod.port}" />
</bean>

Now, we want to create two object that achieve all informations about two connections with id are jedisConnector and jedisConnectorPOD by using annotations.

Normally, we will think about @Autowired annotation with the below example:

@Autowired //bean of id jedisConnector
JedisConnector beanA;

@Autowired //bean of id jedisConnectorPOD
JedisConnector beanB;

But, it does not work like our thought. So how do you use annotations to make it works?

Solution

To solve this problem, we two three solutions.

• Use @Resource

    @Resource(name="jedisConnector")    
    JedisConnector beanA;
  
    @Resource(name="jedisConnectorPOD")
    JedisConnector beanB;
  

  or

    @Resource
    JedisConnector jedisConnector;
  
    @Resource
    JedisConnector jedisConnectorPOD;
  

• Use @Autowired with @Qualifier annotation

    @Autowired
    @Qualifier("jedisConnector")
    JedisConnector beanA;
  
    @Autowired
    @Qualifier("jedisConnectorPOD")
    JedisConnector beanB;
  

Thanks for your reading.