Spring: Access bean property from another bean

Question

I have two beans:

ConfigurationManager:

public class ConfigurationManager
{
    private Configuration configuration;

    public void init() { ... } // Loads a configuration

    // Getters and setters
}

DataCenter:

public class DataCenter
{
    private Configuration configuration;

    ...

    // Getters and setters
}

I would like to get the configuration field of the ConfigurationManager from within my DataCenter bean and I'm not quite sure what the syntax is.

Here's my context file:

<bean id="configurationManager"
      class="com.foo.ConfigurationManager"
      init-method="init">
    <property name="configurationFile" value="etc/configuration.xml"/>
</bean>

<bean id="dataCenter"
      class="com.foo.DataCenter">
    <!-- <property name="storages" ref="configurationManager."/> -->
</bean>

Could somebody please show me how to do this? Thanks in advance!

Answer 1

You can use Spring Expression Language to refer to other bean properties by name. Here's the example given in the docs

<bean id="numberGuess" class="org.spring.samples.NumberGuess">
    <property name="randomNumber" value="#{ T(java.lang.Math).random() * 100.0 }"/>

    <!-- other properties -->
</bean>


<bean id="shapeGuess" class="org.spring.samples.ShapeGuess">
    <property name="initialShapeSeed" value="#{ numberGuess.randomNumber }"/>

    <!-- other properties -->
</bean>

In your case, you could use

<bean id="configurationManager"
      class="com.foo.ConfigurationManager"
      init-method="init">
    <property name="configurationFile" value="etc/configuration.xml"/>
</bean>

<bean id="dataCenter"
      class="com.foo.DataCenter">
    <property name="storages" value="#{configurationManager.configuration}"/> 
</bean>

In similar fashion, you can use @Value annotation in @Bean methods or use it in @Autowired methods.

Answer 2

try this

<bean id="dataCenter" class="com.foo.DataCenter">
    <property name="configuration" value="#{configurationManager.configuration}"/>
</bean>