What Does @Configuration Do In Spring?

What is the use of @autowired annotation 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 @EnableAutoConfiguration in spring?

Annotation Type EnableAutoConfiguration Enable auto-configuration of the Spring Application Context, attempting to guess and configure beans that you are likely to need. Auto-configuration classes are usually applied based on your classpath and what beans you have defined. For example, if you have tomcat-embedded.

Why annotations are used in spring?

Spring framework implements and promotes the principle of control inversion (IOC) or dependency injection (DI) and is in fact an IOC container. Traditionally, Spring allows a developer to manage bean dependencies by using XML-based configuration.

What is the purpose of @component in Spring?

Spring Component annotation is used to denote a class as Component. It means that Spring framework will autodetect these classes for dependency injection when annotation-based configuration and classpath scanning is used.

What is the difference between @component and @ComponentScan?

Using the annotation @ComponentScan , you can tell Spring where do your Spring-managed components lie. … On the other hand, @Component is a generic annotation for any Spring-Managed component. For example – If you create a class called Testing inside the package com. example.

What is Spring configuration annotation?

Spring @Configuration annotation is part of the spring core framework. Spring Configuration annotation indicates that the class has @Bean definition methods. So Spring container can process the class and generate Spring Beans to be used in the application.

How do you set up a spring?

There are three ways to define configuration, available in Spring 4 by default:xml-based configuration, when you describe configuration in xml file;java-based configuration, when configuration is Java class, marked with specific annotations;groovy-based configuration, when configuration is file with Groovy code;

What’s the difference between @controller @component @repository and @service annotations in spring?

@Component: you annotate a class @Component , it tells hibernate that it is a Bean. @Repository: you annotate a class @Repository , it tells hibernate it is a DAO class and treat it as DAO class. Means it makes the unchecked exceptions (thrown from DAO methods) eligible for translation into Spring DataAccessException .

Which is better annotation or XML in spring?

XML configurations can take a lot of work when there are a lot of beans, while annotations minimize the XML configurations. Annotation injection is performed before XML injection. Thus, XML configurations will override that of the annotations.

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.

What is the difference between @configuration and @EnableAutoConfiguration?

The main difference between these annotations is that @ComponentScan scans for Spring components while @EnableAutoConfiguration is used for auto-configuring beans present in the classpath in Spring Boot applications.

What does @bean do in spring?

The @Bean annotation returns an object that spring registers as a bean in application context. The logic inside the method is responsible for creating the instance.

What is use of @bean annotation in spring?

Annotating a class with the @Configuration indicates that the class can be used by the Spring IoC container as a source of bean definitions. The @Bean annotation tells Spring that a method annotated with @Bean will return an object that should be registered as a bean in the Spring application context.

What are the annotations in spring?

Core Spring Framework Annotations@Required. This annotation is applied on bean setter methods. … @Autowired. This annotation is applied on fields, setter methods, and constructors. … @Qualifier. This annotation is used along with @Autowired annotation. … @Configuration. … @ComponentScan. … @Bean. … @Lazy. … @Value.More items…•

What is @service and @component in Spring?

@Component is a generic stereotype for any Spring-managed component or bean. @Repository is a stereotype for the persistence layer. @Service is a stereotype for the service layer. @Controller is a stereotype for the presentation layer (spring-MVC).

What is the use of Autowired annotation in spring?

The @Autowired annotation in spring automatically injects the dependent beans into the associated references of a POJO class. This annotation will inject the dependent beans by matching the data-type (i.e. Works internally as Autowiring byType).

What is difference between @component and @bean in spring?

@Component auto detects and configures the beans using classpath scanning whereas @Bean explicitly declares a single bean, rather than letting Spring do it automatically.

What is qualifier in spring?

The @Qualifier annotation is used to resolve the autowiring conflict, when there are multiple beans of same type. The @Qualifier annotation can be used on any class annotated with @Component or on method annotated with @Bean . This annotation can also be applied on constructor arguments or method parameters.