Can You Describe The Lifecycle Of A Spring Bean In An ApplicationContext?

What is dependency injection and IoC in spring?

Inversion of Control (IoC) and Dependency Injection (DI) are used interchangeably.

IoC is achieved through DI.

By DI, the responsibility of creating objects is shifted from our application code to the Spring container; this phenomenon is called IoC..

Are all spring beans singletons?

Spring’s default scope is singleton. … Here is how the Spring documentation defines singleton scope: Only one shared instance of a singleton bean is managed, and all requests for beans with an id or ids matching that bean definition result in that one specific bean instance being returned by the Spring container.

What is scope of bean in spring?

In Spring, bean scope is used to decide which type of bean instance should be returned from Spring container back to the caller. 5 types of bean scopes are supported : Singleton : It returns a single bean instance per Spring IoC container.

Which is the best dependency injection in Spring?

The good thing about Spring is that it doesn’t restrict you to use either Setter Injection or Constructor Injection and you are free to use both of them in one Spring configuration file. Use Setter injection when a number of dependencies are more or you need readability.

What is factory bean in spring?

Conceptually, a factory bean is very similar to a factory method, but it is a Spring-specific bean that can be identified by the Spring IoC container during bean construction and can be used by container to instantiate other beans.

What is the difference between @bean and @component?

Both approaches aim to register target type in Spring container. The difference is that @Bean is applicable to methods, whereas @Component is applicable to types. Therefore when you use @Bean annotation you control instance creation logic in method’s body (see example above). With @Component annotation you cannot.

What is the bean life cycle in spring?

The life cycle of a Spring bean is easy to understand. When a bean is instantiated, it may be required to perform some initialization to get it into a usable state. Similarly, when the bean is no longer required and is removed from the container, some cleanup may be required.

What is the difference between @bean and @autowired?

Annotating @Bean only registers the service as a bean(kind of an Object) in spring application context. … Annotating a variable with @Autowired injects a BookingService bean(i.e Object) from Spring Application Context.

What are the different types of dependency injection in Spring?

We went through 4 types of dependency injection implemented by Spring framework:Constructor injection — good, reliable and immutable, inject via one of the constructors. … Setter injection — more flexible, mutable objects, injection via setters. … Field injection — fast and convenient, coupling with IoC container.More items…•

Why dependency injection is used in spring?

Dependency Injection is a fundamental aspect of the Spring framework, through which the Spring container “injects” objects into other objects or “dependencies”. Simply put, this allows for loose coupling of components and moves the responsibility of managing components onto the container.

What is the difference between prototype and request scope in spring?

Prototype scope creates a new instance every time getBean method is invoked on the ApplicationContext. Whereas for request scope, only one instance is created for an HttpRequest.

What is bean in spring with example?

A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container. These beans are created with the configuration metadata that you supply to the container. For example, in the form of XML definitions which you have already seen in the previous chapters.

What does the Spring bean lifecycle look like?

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 bean class in spring?

In Spring, the objects that form the backbone of your application and that are managed by the Spring IoC container are called beans. A bean is an object that is instantiated, assembled, and otherwise managed by a Spring IoC container. Otherwise, a bean is simply one of many objects in your application.

How beans are loaded in spring?

xml” spring configuration file is loaded by BeanFactory container class. Even though “beans. xml” configuration file is loaded with BeanFactory container in line number 1, none of the beans will be instantiated.