Dependency injection getObjectForBeanInstance method in spring source code

    protected Object getObjectForBeanInstance(
            Object beanInstance, String name, String beanName, @Nullable RootBeanDefinition mbd) {

        // Don"t let calling code try to dereference the factory if the bean isn"t a factory.
        if (BeanFactoryUtils.isFactoryDereference(name) && !(beanInstance instanceof FactoryBean)) {
            throw new BeanIsNotAFactoryException(transformedBeanName(name), beanInstance.getClass());
        }

        // Now we have the bean instance, which may be a normal bean or a FactoryBean.
        // If it"s a FactoryBean, we use it to create a bean instance, unless the
        // caller actually wants a reference to the factory.
        if (!(beanInstance instanceof FactoryBean) || BeanFactoryUtils.isFactoryDereference(name)) {
            return beanInstance;
        }

        //BeanBean
        //BeanBean
        Object object = null;
        if (mbd == null) {
            //BeanBean
            object = getCachedObjectForFactoryBean(beanName);
        }
        //BeanBean
        if (object == null) {
            // Return bean instance from factory.
            FactoryBean<?> factory = (FactoryBean<?>) beanInstance;
            // Caches object obtained from FactoryBean if it is a singleton.
            //BeanBean
            if (mbd == null && containsBeanDefinition(beanName)) {
                //Bean
                mbd = getMergedLocalBeanDefinition(beanName);
            }
            //BeanBean
            //BeanBean
            boolean synthetic = (mbd != null && mbd.isSynthetic());
            //FactoryBeanRegistrySupportgetObjectFromFactoryBean
            //BeanBean
            object = getObjectFromFactoryBean(factory, beanName, !synthetic);
        }
        return object;
    }

 if (BeanFactoryUtils.isFactoryDereference(name) && !(beanInstance instanceof FactoryBean)) {
            throw new BeanIsNotAFactoryException(transformedBeanName(name), beanInstance.getClass());
        }


if (!(beanInstance instanceof FactoryBean) || BeanFactoryUtils.isFactoryDereference(name)) {
    return beanInstance;
}

if

* FactoryBean * isFactoryDereferencename name & */ if (BeanFactoryUtils.isFactoryDereference(name)) { //NullBean bean if (beanInstance instanceof NullBean) { return beanInstance; } //FactoryBean if (!(beanInstance instanceof FactoryBean)) { throw new BeanIsNotAFactoryException(transformedBeanName(name), beanInstance.getClass()); } } // Now we have the bean instance, which may be a normal bean or a FactoryBean. // If it's a FactoryBean, we use it to create a bean instance, unless the // caller actually wants a reference to the factory. // BeanbeanInstance bean FactoryBean // FactoryBean Bean if (!(beanInstance instanceof FactoryBean) || BeanFactoryUtils.isFactoryDereference(name)) { return beanInstance; }