import com.ab.util.CalendarFactory;

import org.springframework.context.annotation.Bean;

import org.springframework.context.annotation.ComponentScan;

import org.springframework.context.annotation.Configuration;

import java.util.Calendar;

/**

* @author Arpit Bhardwaj

*

* In this Spring Java Based Configuration, you will be learning about some Java-based annotations which will help you configure Spring Beans.

* Using Java based configuration allows you to write your Spring configuration without using XML

*

* @Configuration annotation indicates that Spring IoC container can use it as a source of Beans definitions

* @Bean tells spring that method will return an object which should be registered as a bean in Spring application context.

* @Bean is method level annotation

*

* Stereotype Annotation

* @Component

* @Repository annotation is a specialization of the @Component annotation with similar use and functionality.

* @Service

*

* Spring Bean Scopes

* singleton – only one instance of the spring bean will be created for the spring container.

* This is the default spring bean scope.

* While using this scope, make sure bean doesn’t have shared instance variables otherwise it might lead to data inconsistency issues.

* prototype – new instance will be created every time the bean is requested from the spring container.

* request – This is same as prototype scope, however it’s meant to be used for web applications. A new instance of the bean will be created for each HTTP request.

* session – new instance will be created for each HTTP session by the container.

* application - creates the bean instance for the lifecycle of a ServletContext.

* This is similar to the singleton scope, but there is a very important difference with regards to the scope of the bean.

* When beans are application scoped, the same instance of the bean is shared across multiple servlet-based applications running in the same ServletContext,

* while singleton scoped beans are scoped to a single application context only.

*/

@Configuration

@ComponentScan("com.ab")

public class AppConfig {

@Bean(name="calendar")

public CalendarFactory calendarFactory(){

CalendarFactory calendarFactory = new CalendarFactory();

calendarFactory.addDays(2);

return calendarFactory;

}

@Bean

public Calendar calendar() throws Exception {

return calendarFactory().getObject();

}

/*@Bean(name = "speakerService")

@Scope(value = BeanDefinition.SCOPE_SINGLETON)

//@Scope(value = BeanDefinition.SCOPE_PROTOTYPE)

public SpeakerService getSpeakerService(){

//constructor injection

//SpeakerServiceImpl service = new SpeakerServiceImpl(getSpeakerRepository());

//setter injection

SpeakerServiceImpl service = new SpeakerServiceImpl();

//setter injection can also be auto wired by marking setter as AutoWired

//service.setRepository(getSpeakerRepository());

return service;

}

@Bean(name = "speakerRepository")

public SpeakerRepository getSpeakerRepository(){

return new HibernateSpeakerRepositoryImpl();

}*/

}