Question on a specific use case on spring <util:map>

Question

Hi,

I'm just trying to explore one use case of using object as a value in a spring map. Here's my example

<util:map id="someSourceMap" map-class="java.util.HashMap">
<entry key="source1" value="testLine"/>
<entry key="source2" value="testLine2"/>
</util:map>

<bean id="testLine1" class="com.test.ProductLineMetadata" scope="prototype">
<constructor-arg value="PRODUCT_LINE_1"></constructor-arg>
<constructor-arg value="TYPE_1"></constructor-arg>
</bean>

<bean id="testLine2" class="com.test.ProductLineMetadata"scope="prototype">
<constructor-arg value="PRODUCT_LINE_2"></constructor-arg>
<constructor-arg value="TYPE_2"></constructor-arg>
</bean>

What I'm trying to achieve is to create a map in which the value will be a new instance of ProductLineMetadata object with different parameters set through constructor argument. I don't want to create a separate bean entry for each key with the desired constructor values. Is there a better way of doing this by somehow specifying the parameters inside the map declaration itself?

Any pointer will be highly appreciated.

Thanks

Answer 1

You mean something like this?

<util:map id="someSourceMap" map-class="java.util.HashMap">
  <entry key="source1">
    <bean class="com.test.ProductLineMetadata">
      <constructor-arg value="PRODUCT_LINE_1"/>
      <constructor-arg value="TYPE_1"/>
    </bean>
  </entry>
  <entry key="source2">
    <bean class="com.test.ProductLineMetadata">
      <constructor-arg value="PRODUCT_LINE_2"/>
      <constructor-arg value="TYPE_2"/>
    </bean>
  </entry>
</util:map>

Answer 2

If your testLines are just test data rather than regular beans you may use more lightweight approach to declare them, for example, Spring Expression Language (since Spring 3):

<util:map id="someSourceMap" map-class="java.util.HashMap"> 
    <entry key="source1" 
        value="#{new com.test.ProductLineMetadata('PRODUCT_LINE_1', 'TYPE_1')}"/> 
    <entry key="source2" 
        value="#{new com.test.ProductLineMetadata('PRODUCT_LINE_2', 'TYPE_2')}"/> 
</util:map>