Question: What Is Bean Annotation In Spring?

What does Bean annotation do?

@Bean is a method-level annotation and a direct analog of the XML element.

The annotation supports most of the attributes offered by , such as: init-method , destroy-method , autowiring , lazy-init , dependency-check , depends-on and scope ..

What is spring bean life cycle?

Advertisements. 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.

How do you call beans in spring?

Spring @Bean Annotation is applied on a method to specify that it returns a bean to be managed by Spring context. Spring Bean annotation is usually declared in Configuration classes methods. In this case, bean methods may reference other @Bean methods in the same class by calling them directly.

Why do we use annotation?

Annotations are used to provide supplement information about a program. … Annotations help to associate metadata (information) to the program elements i.e. instance variables, constructors, methods, classes, etc. Annotations are not pure comments as they can change the way a program is treated by compiler.

How do you Autowire a bean in spring?

The easiest way to autowire a bean is by using the @Autowire annotation, to avoid the xml configuration. It can be used to autowire a bean on the setter method, on a constructor or a field. Below, we will introduce all possible ways to autowire a bean in Spring. Our preferred development environment is Eclipse.

Is Spring beans are thread safe?

So eventually thread safety depends on the code and the code only. And this is the reason why Spring beans are not thread safe per se. Spring singleton beans are NOT thread-safe just because Spring instantiates them. … Spring just manage the life cycle of singleton bean and maintains single instance of object.

What is a bean 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 annotation is defined in bean in spring?

We can declare beans using the @Bean annotation in a configuration class. Or we can mark the class with one of the annotations from the org. springframework. stereotype package and leave the rest to component scanning.

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 is use of @autowired in spring?

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 difference between @component and @bean?

@Component is a class level annotation whereas @Bean is a method level annotation and name of the method serves as the bean name. @Component need not to be used with the @Configuration annotation where as @Bean annotation has to be used within the class which is annotated with @Configuration.

What is the difference between @configuration and @component in Spring?

@Component Indicates that an annotated class is a “component”. Such classes are considered as candidates for auto-detection when using annotation-based configuration and classpath scanning. A @Configuration is also a @Component, but a @Component cannot act like a @Configuration.

How bean is created in spring boot?

Spring @Bean annotation tells that a method produces a bean to be managed by the Spring container. It is a method-level annotation. During Java configuration ( @Configuration ), the method is executed and its return value is registered as a bean within a BeanFactory .

What is difference between @autowired and @resource in spring?

The main difference is that @Autowired wires per type and @Resource wires per bean name. @Autowired is a spring annotation whereas @Resource is specified by the JSR-250. … So the latter is part of normal java where as @Autowired is only available by spring.

How many ways can you configure bean in spring?

Spring Framework provides three ways to configure beans to be used in the application. Annotation Based Configuration – By using @Service or @Component annotations. Scope details can be provided with @Scope annotation. XML Based Configuration – By creating Spring Configuration XML file to configure the beans.

What is meant by annotation in spring?

So instead of using XML to describe a bean wiring, you can move the bean configuration into the component class itself by using annotations on the relevant class, method, or field declaration. … Annotation injection is performed before XML injection.

What is required annotation in spring?

Advertisements. The @Required annotation applies to bean property setter methods and it indicates that the affected bean property must be populated in XML configuration file at configuration time. Otherwise, the container throws a BeanInitializationException exception.

What is the use of @service annotation in spring?

Spring @Service annotation is used with classes that provide some business functionalities. Spring context will autodetect these classes when annotation-based configuration and classpath scanning is used.