@Configuration annotation

  • @Configuration itself is a Component
  • Hence @ComponentScan is required for @Configuration as well
  • @Configuration annotation indicates that a class declares one or more @Bean methods and may be processed by the Spring container to generate bean definitions and service requests for those beans at runtime.
  • @Configuration is the heart of the Java-based configuration mechanism that was introduced in Spring 3. It provides an alternative to XML-based configuration.
  • Where as @Configuration is used to create component which is used by spring framework to create the application context


It is a way in which you can load a normal Java Object into a Spring Container

public interface DemoManager {
    public String getServiceName();
}
 
public class DemoManagerImpl implements DemoManager
{
    @Override
    public String getServiceName()
    {
        return "My first service with Spring 3";
    }
}

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
 
import com.howtodoinjava.core.beans.DemoManager;
import com.howtodoinjava.core.beans.DemoManagerImpl;
 
@Configuration
public class ApplicationConfiguration {
 
    @Bean(name="demoService")
    public DemoManager helloWorld() 
    {
        return new DemoManagerImpl();
    }
}

package com.howtodoinjava.core.verify;
 
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;
 
import com.howtodoinjava.core.beans.DemoManager;
import com.howtodoinjava.core.config.ApplicationConfiguration;
 
public class VerifySpringCoreFeature
{
    public static void main(String[] args)
    {
        ApplicationContext context = new AnnotationConfigApplicationContext(ApplicationConfiguration.class);
 
        DemoManager  obj = (DemoManager) context.getBean("demoService");
 
        System.out.println( obj.getServiceName() );
    }
}

Difference between @Configuration and @Component

Reference :

Leave a Comment