如何以编程方式获取带有类和限定符的bean？

Question

可以在@Autowired类和@QualifierSpring中使用bean 。

如何以编程方式做同样的事情？即搜索上下文的bean给它的类和限定符？

我看到了很多getBean()方法，但没有一个方法明确声明它可以做到这一点。

Answer 1

您可以使用BeanFactoryAnnotationUtils.qualifiedBeanOfType(BeanFactory beanFactory, Class<T> beanType, String qualifier)：

/**
     * Obtain a bean of type {@code T} from the given {@code BeanFactory} declaring a
     * qualifier (e.g. via {@code <qualifier>} or {@code @Qualifier}) matching the given
     * qualifier, or having a bean name matching the given qualifier.
     * @param beanFactory the BeanFactory to get the target bean from
     * @param beanType the type of bean to retrieve
     * @param qualifier the qualifier for selecting between multiple bean matches
     * @return the matching bean of type {@code T} (never {@code null})
     * @throws NoUniqueBeanDefinitionException if multiple matching beans of type {@code T} found
     * @throws NoSuchBeanDefinitionException if no matching bean of type {@code T} found
     * @throws BeansException if the bean could not be created
     * @see BeanFactory#getBean(Class)
     */
    public static <T> T qualifiedBeanOfType(BeanFactory beanFactory, Class<T> beanType, String qualifier)
            throws BeansException;

我认为这正是您所需要的。

Answer 2

如果您希望 Spring 以@Autowired编程方式处理字段/属性，您需要AutowireCapableBeanFactory从您的实例中获取实例ApplicationContext并调用factory.autowireBean(myClassInstanceWithBeansToAutowire);.