Inject the value of an enum into a property using spring

java, spring

Solution

If you don't have access to the expression language you'll have to fall back to an explicit `MethodInvokingFactoryBean`

<bean id="firstKey" class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
  <property name="targetObject"><util:constant static-field="package.MyEnum.ABC"/></property>
  <property name="targetMethod" value="value" />
</bean>

You could shorten the repetitive XML a bit with an abstract parent bean definition.

<bean name="enumValue" abstract="true"
      class="org.springframework.beans.factory.config.MethodInvokingFactoryBean">
  <property name="targetMethod" value="value" />
</bean>

<bean id="firstKey" parent="enumValue">
  <property name="targetObject"><util:constant static-field="package.MyEnum.ABC"/></property>
</bean>

You could also skip the `MethodInvokingFactoryBean` and just use

<util:constant id="MyEnum_ABC" static-field="package.MyEnum.ABC" />
<bean id="firstKey" factory-bean="MyEnum_ABC" factory-method="value" />

but that means declaring separate top-level beans for each enum constant as well as for their `value()`, whereas using MIFB allows you to use anonymous inner beans.

Problem

I have an enum similar to the below ``` public enum MyEnum { ABC("some string"), DEF("some string"), GHI("another string"); String value; private MyEnum(String value) { this.value = value; } public String value() { return this.value; }} ``` And I would like to make a util:map using the value of the enum as the key not the enum itself. So the map would look like this: ``` "some string" -> "mapped output 1" "another string" -> "mapped output 2" ``` I know I can use util:constant to get the enum but i need the value the enum represents. So my config file at the minute looks like this: ``` <util:constant id="firstKey" static-field="package.MyEnum.ABC"/> <util:constant id="secondKey" static-field="package.MyEnum.GHI" /> <util:map id="myMap"> <entry key-ref="firstKey" value="mapped output 1" /> <entry key-ref="secondKey" value="mapped output 2" /></util:map> ``` Is there a way I can get .value() or even get access to the value property to use it as the key? I tried declaring the key type to be string in the hope spring would work it out but it seems to have just ignored this. Using spring 2.5.1 and I cannot modify the enum

Original source