spring中自定义对象交给spring容器管理的4种方式

1、自定义一个 BeanDefinition

@Component
public class BeanPro implements BeanDefinitionRegistryPostProcessor, PriorityOrdered, Ordered {
    @Override
    public void postProcessBeanDefinitionRegistry(BeanDefinitionRegistry registry) throws BeansException {
        //查询BeanDefinition
        final String[] beanDefinitionNames = registry.getBeanDefinitionNames();
        for (String beanDefinitionName : beanDefinitionNames) {
            BeanDefinition beanDefinition = registry.getBeanDefinition(beanDefinitionName);
            System.out.println(beanDefinition);
        }

        GenericBeanDefinition genericBeanDefinition = new GenericBeanDefinition();
        genericBeanDefinition.setBeanClass(BeanDefinitionBean.class);
        MutablePropertyValues propertyValues = genericBeanDefinition.getPropertyValues();
        propertyValues.add("name","Jack");
        registry.registerBeanDefinition("beanDefinitionBean",genericBeanDefinition);


    }

    @Override
    public void postProcessBeanFactory(ConfigurableListableBeanFactory beanFactory) throws BeansException {
        BeanDefinitionRegistry registry = (BeanDefinitionRegistry) beanFactory;
        String[] beanDefinitionNames = registry.getBeanDefinitionNames();

        DefaultListableBeanFactory beanFactory1 = (DefaultListableBeanFactory)beanFactory;
        beanFactory1.setAllowBeanDefinitionOverriding(true);
        beanFactory1.setAllowCircularReferences(true);
        beanFactory1.setAllowRawInjectionDespiteWrapping(true);
    }

    @Override
    public int getOrder() {
        return 0;
    }
}

2、手动创建了对象，并且交给spring管理了

applicationContext.getBeanFactory().registerSingleton("jack", new Jack());

3、实现 FactoryBean接口

/** 
 *
 * 灵活定义需要我们自己创建的实例的时候，我们可以实现factoryBean接口
 * 在getObject方法里面定义实例化过程
 *
 */
@Component
public class FactoryBeanDemo implements FactoryBean {
    @Override
    public Object getObject() throws Exception {
        return new Student();
    }

    @Override
    public Class<?> getObjectType() {
        return Student.class;
    }
}

4、@Bean注解

本文地址：https://blog.csdn.net/qq_31391225/article/details/112230203