7.7. Bean Factory

<bean name="Object" class="java.lang.Object"/>
<beanfactory name="DefaultPrototype" class="org.jboss.demos.ioc.factory.Prototype">
  <property name="value"><inject bean="Object"/></property>
</beanfactory>
<beanfactory name="EnhancedPrototype" class="org.jboss.demos.ioc.factory.Prototype" factoryClass="org.jboss.demos.ioc.factory.EnhancedBeanFactory">
  <property name="value"><inject bean="Object"/></property>
</beanfactory>
<beanfactory name="ProxiedPrototype" class="org.jboss.demos.ioc.factory.UnmodifiablePrototype" factoryClass="org.jboss.demos.ioc.factory.EnhancedBeanFactory">
  <property name="value"><inject bean="Object"/></property>
</beanfactory>
<bean name="PrototypeCreator" class="org.jboss.demos.ioc.factory.PrototypeCreator">
  <property name="default"><inject bean="DefaultPrototype"/></property>
  <property name="enhanced"><inject bean="EnhancedPrototype"/></property>
  <property name="proxied"><inject bean="ProxiedPrototype"/></property>
</bean>
			
			
			

public class EnhancedBeanFactory extends GenericBeanFactory {
    public EnhancedBeanFactory(KernelConfigurator configurator)
    {
	super(configurator);
    }
    public Object createBean() throws Throwable
    {
	Object bean = super.createBean();
	Class clazz = bean.getClass();
	if (clazz.isAnnotationPresent(SetterProxy.class))
	    {
		Set<Class> interfaces = new HashSet<Class>();
		addInterfaces(clazz, interfaces);
		return Proxy.newProxyInstance(
					      clazz.getClassLoader(),
					      interfaces.toArray(new Class[interfaces.size()]),
					      new SetterInterceptor(bean)
					      );
	    }
	else
	    {
		return bean;
	    }
    }
    protected static void addInterfaces(Class clazz, Set<Class> interfaces)
    {
	if (clazz == null)
	    return;
	interfaces.addAll(Arrays.asList(clazz.getInterfaces()));
	addInterfaces(clazz.getSuperclass(), interfaces);
    }
    private class SetterInterceptor implements InvocationHandler
    {
	private Object target;
	private SetterInterceptor(Object target)
	{
	    this.target = target;
	}
	public Object invoke(Object proxy, Method method, Object[] args) throws Throwable
	{
	    String methodName = method.getName();
	    if (methodName.startsWith("set"))
		throw new IllegalArgumentException("Cannot invoke setters.");
	    return method.invoke(target, args);
	}
    }
}

public class PrototypeCreator {
    ...
	public void create() throws Throwable
    {
	ValueInvoker vi1 = (ValueInvoker)bfDefault.createBean();
	vi1.setValue("default");
	ValueInvoker vi2 = (ValueInvoker)enhanced.createBean();
	vi2.setValue("enhanced");
	ValueInvoker vi3 = (ValueInvoker)proxied.createBean();
	try
	    {
		vi3.setValue("default");
		throw new Error("Should not be here.");
	    }
	catch (Exception ignored)
	    {
	    }
    }