Automatic object initializing based on type in spring

[Lucas Vo]

Hi there everybody,

I have a list of Class types that I need to iterate over and for every type in that list, Spring needs to automatically find the correct sort of object to initialize.

For example : I have a ClassA and ClassB. When for example there is a type User, a ClassA needs to be initialized with certain parameters (which are defined in the context.xml). When for example there is a type of Message, it should also make an object from type ClassA but with different parameters, which are again defined in the context.xml.

How would I go about doing this? I have looked at the inversion of control feature of spring but cannot seem to find the correct implementation for my specific purpose

One idea was that I make a bean for every kind of possible type such as

 <bean id="classAconfig" class="ClassA">
        <property name="type" value="User.class"/>
        <property name="fields">
            <list>
                <value>id</value><value>email</value>
            </list>
        </property>
        <property name="map">
            <map>
                <entry key="id" value="1"/><entry key="login" value="1"/><entry key="email" value="1"/>
            </map>
        </property>
    </bean>

Kind regards,

Merlijn

[Mark Spritzler]

I don't quite understand what you mean.

But I can point you to some ideas.

1) Use @PostConstruct and @Autowired on a List<typesHere>, in the postConstruct loop through the list and create instances?
2) Use Spring Expression language in your config, calling a method that goes through your list and creates instances based on that.
3) implement a BeanFactoryPostProcessor that looks at all the BeanDefinitions in your ApplicationContext and for every type, create a BeanDefinition for your class types
4) implement a BeanFactory or POJO factory, which creates those objects.

Just ideas without understanding your needs.

Mark