Class as Map Key

[mediaslave]

Hello,
Is it possiable to have a Class object be a key for a map. Currently when I inject it with spring , my key is a String rather than a Class.

I believe there was a recent fix to allow non string keys, were Classes addressed in this fix also?

I have stepped throught the code and ClassEditor doesn't seem to get called for the map keys.

I am using Spring 1.2.4

Below is snippet from my application context.

Thanks for any help,
Tyler

<property name="daoMap">
			<map>
				
				<entry key="org.example.webapp.domain.PhoneBook" value-ref="phoneBookDAO" />
				<entry key="org.example.webapp.domain.Salary" value-ref="salaryDAO" />
				<entry key="org.example.webapp.domain.MessageBoard" value-ref="messageBoardDAO" />
				
			</map>
		</property>

[Alarmnummer]

Maybe you could use something like this:

 public class ClassFactoryBean implements FactoryBean,InitializingBean{
 	
 	public ClassFactoryBean(String className){
 		_className = className;
 	}
 
 	public ClassFactoryBean(){
 	}

 	public afterPropertiesSet(){
 		if(_className == null)
 			throw new IllegalArgumentException("className is missing");
 	}
 	
 	public void setClass(String className){
 		_className = className;
 	}
 	
 	public Object getObject(){
 		return Class.forName(_className);
 	}	
 	
 	public Class getObjectType(){
 		return Class.class;
 	}
 	
 	public boolean isSingleton(){
 		return true;
 	}
 }

<property name="daoMap">
	<map>            
		<entry>
			<key>
				<bean class="ClassFactoryBean">
					<constructor-arg value="org.example.webapp.domain.Salary"/>
				</bean>
			</key>
			<value><ref bean="salaryDao"/><value>
		</entry>		
	</map>
</property

I must admit it isn`t the most prettiest thing I have seen. But it should work.

[mediaslave]

Yeah I could do that. But I agree its not the prettiest xml in the world.

Other thing I could do is to change my code that pulls out the DAO from the map by using myObject.getClass().getName() Or Maybe put a a conditional to do both, to cover both my bases. But I not happy with the that solution either.

Funny thing is I thought I had this working before in some other code I did. I will try and search for it and see if it works the way I remember it.

I will post what I find.

Thanks,
Tyler

[Rick Evans]

Hi

Use the <key/> element as a child element within your <entry/> for your <map/>; to wit...

<property name="daoMap">
<map>
	<entry value-ref="phoneBookDAO">
		<key><value>org.example.webapp.domain.PhoneBook</value></key>
	</entry>
</map>
</property>

It sure would be nice if the <key/> element supported the shortcut 'value' and 'ref' attributes too though... it doesn't so don't go there

The fix you mentioned can be found here.

The DTD is always a good place to start looking for what can and can't be done XML-wise.

Ciao
Rick

[Colin Yates]

Can you not specify

<value type="java.lang.Class">my.company.MyClass</value>