Spring Part 04 - Setter Injection (Class)

Spring - Dependency Injection

Dependency Injection using class

Sample Program for Dependency Injection using 'Spring Framework'

beans_di.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
        https://www.springframework.org/schema/beans/spring-beans.xsd">

    <bean id="car" class="com.ah.di.Car">
        <property name="engine">
            <bean class="com.ah.di.Engine"/>
        </property>
    </bean>

</beans>

package com.ah.di;

import org.springframework.context.ApplicationContext;

import org.springframework.context.support.ClassPathXmlApplicationContext;

public class Test {

    public static void main(String[] args) {

        ApplicationContext context = new ClassPathXmlApplicationContext("beans_di.xml");

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

        car.checkCarEngine();

    }

}

package com.ah.di;



public class Car {

    private Engine engine;



    public void setEngine(Engine engine) {

        this.engine = engine;

    }

    public void checkCarEngine(){

        if(engine!=null){

            engine.testEngine();

        }else{

            System.out.println("Engine is dead");

        }

    }

}

package com.ah.di;

public class Engine {

    public void testEngine(){

        System.out.println("engine is working" );

    }

}

                                                                         Watch Demo