Spring Part 09 - @Bean

 Spring - @Bean

package com.ah.di;

import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan
public class AppConf {

    @Bean("car")
    public Car carBean(){
        Car car = new Car();
        return car;
    }
}

package com.ah.di;

import org.springframework.beans.factory.annotation.Autowired;

public class Car {

    @Autowired
    private Engine engine;

    public void displayCarInfo(){
        System.out.println("car class display method\n");

        if(engine==null){
            System.out.println("No engine object");
        }else{
            engine.testEngine();
        }
    }

}

package com.ah.di;

import org.springframework.stereotype.Component;

@Component
public class Engine {

    public void testEngine(){
        System.out.println("testEngine() method of 

Engine class")
    }
}

package com.ah.di;

import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.AnnotationConfigApplicationContext;

public class Test {

    public static void main(String[] args) {
        ApplicationContext context =
    new AnnotationConfigApplicationContext

(AppConf.class);

    var carObj = context.getBean("car",Car.class);
     carObj.displayCarInfo();

     //displyAppContextBeanInfo(context);
    }

    public static void displyAppContextBeanInfo(ApplicationContext context ){
         for(String bean : 

context.getBeanDefinitionNames()){
            System.out.println(bean);
        }
    }

}

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Spring Part 08 - @ComponentScan & @Configuration

 Spring - @ComponentScan & @Configuration

In this Part of Spring Framework  we will avoid using Spring configuration xml file, instead we will maintain configuration at java side by using the '@Configuration' annotation.

package com.ah.di.samp;

import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;

@Configuration
@ComponentScan(basePackages = "com.ah.di")
public class AppConf {
}

package com.ah.di;

import org.springframework.stereotype.Component;

@Component
public class Car {

    public void displayCarInfo(){
        System.out.println("car class display method");
    }
}

package com.ah.di;

import com.ah.di.samp.AppConf;
import org.springframework.context.ApplicationContext;
import org.springframework.context.annotation.

AnnotationConfigApplicationContext;

public class Test {

    public static void main(String[] args) {

        ApplicationContext context =

    new AnnotationConfigApplicationContext

(AppConf.class);

    var carObj = context.getBean("car",Car.class);
     carObj.displayCarInfo();

     //displyAppContextBeanInfo(context);

    }

    public static void displyAppContextBeanInfo

(ApplicationContext context ){

         for(String bean : context.

getBeanDefinitionNames()){

            System.out.println(bean);

        }
    }
}

                                                                        Watch Demo