Is there a difference in the context annotation config and context component scan tags?

Asked By: Guiu Bougtib | Last Updated: 23rd March, 2020
Category: technology and computing programming languages
4.1/5 (196 Views . 12 Votes)
1) First big difference between both tags is that <context:annotation-config> is used to activate applied annotations in already registered beans in application context.

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Accordingly, what is context annotation config />?

<context:annotation-config> is used to activate annotations in beans already registered in the application context (no matter if they were defined with XML or by package scanning).

Subsequently, question is, 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.

Similarly, you may ask, what does context component scan do?

Moreover, <context:component-scan> recognizes bean annotations that <context:annotation-config> doesn't detect. Basically, <context:component-scan> detects the annotations by package scanning. To put it differently, it tells Spring which packages need to be scanned to look for the annotated beans or components.

How do you turn on annotation wiring?

To enable @Autowired, you have to register 'AutowiredAnnotationBeanPostProcessor', and you can do it in two ways :

  1. Include <context:annotation-config /> Add Spring context and <context:annotation-config /> in bean configuration file.
  2. Include AutowiredAnnotationBeanPostProcessor.

39 Related Question Answers Found

What is spring Autowiring?

Autowiring in Spring. Autowiring feature of spring framework enables you to inject the object dependency implicitly. It internally uses setter or constructor injection. Autowiring can't be used to inject primitive and string values. It works with reference only.

How do I use context component scan?

Put this “ context:component ” in bean configuration file, it means, enable auto scanning feature in Spring. The base-package is indicate where are your components stored, Spring will scan this folder and find out the bean (annotated with @Component) and register it in Spring container.

What are spring annotations?

Some of the spring core framework annotations are:
  • @Configuration : Used to indicate that a class declares one or more @Bean methods.
  • @Bean : Indicates that a method produces a bean to be managed by the Spring container.
  • @PreDestroy and @PostConstruct are alternative way for bean initMethod and destroyMethod.

What is @component annotation 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.

How do you write an annotation based Spring?


a. @Required Annotation in Spring
  1. Add the Spring Libraries that are required using the Add External JARs options.
  2. Create Student. java and MainApp.
  3. Write the Beans. xml configuration file under the src folder.
  4. Finally, write code for all Java files and Bean config file and run the application as described.

What is MVC annotation driven?

mvc:annotation-driven is used for enabling the Spring MVC components with its default configurations. If you dont include mvc:annotation-driven also your MVC application would work if you have used the context:component-scan for creating the beans or defined the beans in your XML file.

Where do I put component scans?

put @ComponentScan at the top of your package tree. You can also use the basePackages attribute to specify where to start the scanning. If you want to scan all annoted classes, put the class annoted with @ComponentScan in com. app package.

Can we replace @controller with @component?

Instead of using @Component on a controller class in Spring MVC, we use @Controller, which is more readable and appropriate. Even if you replace @Controller annotation with @Compoenent, Spring can automatically detect and register the controller class but it may not work as you expect with respect to request mapping.

How do I use component scan in spring boot?


This part of “telling Spring where to search” is called a Component Scan. You define the packages that have to be scanned. Once you define a Component Scan for a package, Spring would search the package and all its sub packages for components/beans. If you are using Spring Boot, check configuration in Approach 1.

What is @configuration in spring?

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 does Spring component scan work?

How does component-scan work in Spring Framework. In Spring configuration xml file, we can define a package for tag component-scan, which tells Spring framework to search all classes within this specified package, to look for those classes which are annotated with @Named or @Component.

What is base package in spring?

The base-package is indicate where are your components stored, Spring will scan this folder and find out the bean (annotated with @Component) and register it in Spring container.

What is Classpath scanning in spring?

Spring Classpath Scanning & Managed Components. This means Spring is able to auto scan, detect and instantiate beans from pre-defined project package, hence saving us from tedious beans/component declaration in XML file.

What is bean 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. These beans are created with the configuration metadata that you supply to the container.

What is spring bean life cycle?

Spring (Coffee) Bean Lifecycle. The Spring IoC (Inversion of Control) container manages Spring beans. A “Spring bean” is just a Spring-managed instantiation of a Java class. The Spring IoC container is responsible for instantiating, initializing, and wiring beans. The container also manages the life cycle of beans.

What is the difference between bean id and bean name in spring?

The only difference between an id and a name is that a name can contain multiple aliases separated by a comma, semicolon or whitespace, whereas an id must be a single value. In XML-based configuration metadata, you use the id and/or name attributes to specify the bean identifier(s).