What is Beanfactorypostsprocessor Spring?

Spring BeanFactoryPostProcessor works on the bean definitions or configuration meta data of the bean before beans are actually created. With BeanFactoryPostProcessor we can modify exiting bean definitions or create our new bean definitions. Spring provides some built-in implementations of BeanFactoryPostProcessor .

What is bean life cycle in Spring?

Bean life cycle is managed by the spring container. When we run the program then, first of all, the spring container gets started. After that, the container creates the instance of a bean as per the request, and then dependencies are injected. And finally, the bean is destroyed when the spring container is closed.

What is difference between BeanPostProcessor and BeanFactoryPostProcessor?

BeanFactoryPostProcessor implementations are “called” during startup of the Spring context after all bean definitions will have been loaded while BeanPostProcessor are “called” when the Spring IoC container instantiates a bean (i.e. during the startup for all the singleton and on demand for the proptotypes one)

What is the name of bean factory post processor?

A bean factory post-processor is a java class which implements the org. springframework. beans. factory.

What is a BeanPostProcessor?

A bean post processor allows for custom modification of new bean instances created by spring bean factory. If you want to implement some custom logic after the Spring container finishes instantiating, configuring, and initializing a bean, we can plug in one or more BeanPostProcessor implementations.

What is IoC Spring?

Spring IoC Container is the core of Spring Framework. It creates the objects, configures and assembles their dependencies, manages their entire life cycle. The Container uses Dependency Injection(DI) to manage the components that make up the application.

What is the purpose of @autowired in Spring?

The @Autowired annotation provides more fine-grained control over where and how autowiring should be accomplished. The @Autowired annotation can be used to autowire bean on the setter method just like @Required annotation, constructor, a property or methods with arbitrary names and/or multiple arguments.

What is the use of BeanFactoryPostProcessor?

BeanFactoryPostProcessor implementation is used to read the configuration metadata and potentially change it before beans are instantiated by IOC container.

What is PropertyPlaceholderConfigurer in Spring?

The PropertyPlaceholderConfigurer is a property resource configurer that resolves placeholders in bean property values of context definitions. It pulls values from a properties file into bean definitions.

What is PostConstruct Spring?

Spring calls the methods annotated with @PostConstruct only once, just after the initialization of bean properties. Keep in mind that these methods will run even if there’s nothing to initialize. The method annotated with @PostConstruct can have any access level, but it can’t be static.

What is afterPropertiesSet?

The afterPropertiesSet or @PostConstruct annotated method is called after an instance of class is created and all the properties have been set. For instance if you would like to preload some data that can be done in this method as all the dependencies have been set.

What is difference between IoC and DI?

Inversion of Control (IoC) refers to a programming style where a framework or runtime, controls the program flow. Inversion of control means we are changing the control from normal way. It works on Dependency Inversion Principle. DI is a software design pattern that allow us to develop loosely coupled code.

What is @component and @autowired in Spring boot?

Enable @Autowired in Spring Boot In the spring boot application, all loaded beans are eligible for auto wiring to another bean. The @Component annotation is used to load a java class as a bean. All classes with annotation such as @Component, @bean etc are auto-wired in the spring boot application.

What is beanfactorypostprocessor in spring spring?

Spring provides multiple BeanFactoryPostProcessor beans, so it invoked to resolve run time dependencies such reading value from external property files. In Spring application, BeanFactoryPostProcessor can modify the definition of any bean.

Can I define a beanfactorypostprocessor in a single container?

If you define a BeanFactoryPostProcessor in one container, it will only be applied to the bean definitions in that container. ( postProcessAfterInitialization (Object bean, String beanName) & postProcessBeforeInitialization (Object bean, String beanName) ).

What is wrong with @bean method myconfigbean?

WARNING: @Bean method MyConfig.myConfigBean is non-static and returns an object assignable to Spring’s BeanFactoryPostProcessor interface. This will result in a failure to process annotations such as @Autowired, @Resource and @PostConstruct within the method’s declaring @Configuration class.