How to programmatically create bean definition wit

2019-01-22 03:41发布

问题:

I want to programmatically add a bean definition to an application context, but some properties of that definition are other beans from that context (I know their names). How can I do this so that those properties will be injected?

For example:

GenericBeanDefinition beanDef = new GenericBeanDefinition();
beanDef.setBeanClass(beanClass);

MutablePropertyValues values = new MutablePropertyValues();
values.addPropertyValue("intProperty", 10);
values.addPropertyValue("stringProperty", "Hello, world");
values.addPropertyValue("beanProperty", /* What should be here? */);

beanDef.setPropertyValues(values);

I'm using Spring 3.0.

回答1:

Use RuntimeBeanReference:

values.addPropertyValue("beanProperty", new RuntimeBeanReference("beanName")); 


回答2:

I would add a bean like this that has access to the applicationContext:

public class AppContextExtendingBean implements ApplicationContextAware{


    @Override
    public void setApplicationContext(ApplicationContext applicationContext) throws BeansException{

        AutowireCapableBeanFactory beanFactory = applicationContext.getAutowireCapableBeanFactory();

        // do it like this
        version1(beanFactory);

        // or like this
        version2(beanFactory);

    }

    // let spring create a new bean and then manipulate it (works only for singleton beans, obviously) 
    private void version1(AutowireCapableBeanFactory beanFactory){
        MyObject newBean = (MyObject) beanFactory.createBean(MyObject.class,AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE, true);
        newBean.setBar("baz");
        newBean.setFoo("foo");
        newBean.setPhleem("phleem");
        beanFactory.initializeBean(newBean, "bean1");
    }

    // create the object manually and then inject it into the spring context
    private void version2(AutowireCapableBeanFactory beanFactory){
        MyObject myObject=new MyObject("foo","phleem");
        myObject.setBar("baz");
        beanFactory.autowireBean(myObject);
        beanFactory.initializeBean(myObject, "bean2");
    }


}


回答3:

I found the solution. I have to use another BeanDefinition as a property, like this:

GenericBeanDefinition bd2 = new GenericBeanDefinition();
bd2.setBeanClass(Dependency.class);

GenericBeanDefinition bd1 = new GenericBeanDefinition();
bd1.setBeanClass(Component.class);

MutablePropertyValues values = new MutablePropertyValues();
values.addPropertyValue("dependency", bd2);

bd1.setPropertyValues(values);


回答4:

You can:

  • using the javaconfig project.
  • using BeanDefinitionParser - but this is a bit ugly to write.