"Welcome To Ashok IT"				
			                     "Spring Boot and MicroServices"
                                              Topic : Dependency Injection
                                              Date  : 23/08/2024
                                                (Session - 08)                               
_____________________________________________________________________________________________________________________________
Yesterday Session
=================
* We completed the First Spring Application development.

* We have seen how to perform the Dependency Injection using setter Injection and constructor Injection.

* If dependencies of Spring Bean injected by using setter method of a class called "Setter Injection".

* If dependencies of Spring Bean injected by using constructor of a class called "Constructor injection".

* We have seen how to activate the Spring Container and how to request the spring bean from container as well.


Today Session 
=============
* Will be deep dive into Dependency Injection Mechanism using various types of properties in Spring Bean class.

* will be covering how to work with DefaultListableBeanFactory class because XmlBeanFactory Class got deprecated.

Student.java
============
package com.ashokit.spring.beans;

import java.util.Arrays;
import java.util.List;

public class Student {
	
	private int id;
	private String name;
	private String course;
	private float fee;
	private String[] emails;
	private List<String> contactNos;
	
	public Student() {
		System.out.println("Student Class Non-parameterized Constructor....");
	}
	
	public void setId(int id) {
		this.id = id;
	}
	
	public void setName(String name) {
		this.name = name;
	}
	
	public void setCourse(String course) {
		this.course = course;
	}
	
	public void setFee(float fee) {
		this.fee = fee;
	}
	
	public void setEmails(String[] emails) {
		this.emails = emails;
	}
	
	public void setContactNos(List<String> contactNos) {
		this.contactNos = contactNos;
	}

	@Override
	public String toString() {
		return "Student [id=" + id + ", name=" + name + ", course=" + course + ", fee=" + fee + ", emails="
				+ Arrays.toString(emails) + ", contactNos=" + contactNos + "]";
	}
}


spring.xml
==========
<beans xmlns="http://www.springframework.org/schema/beans"
       xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
       xmlns:p="http://www.springframework.org/schema/p"
       xsi:schemaLocation="http://www.springframework.org/schema/beans
       https://www.springframework.org/schema/beans/spring-beans.xsd">
   
       <!-- configuring the Java Class as spring Bean -->
   <bean id="wb" class="com.ashokit.spring.beans.Welcome">
	   <!-- Injecting the value of message property using setter method -->
	    <property name="message" value="Welcome To AshokIT For Spring Framework"/>
   </bean>
   
      <!-- configuring the Java Class as spring Bean -->
   <bean id="db" class="com.ashokit.spring.beans.Demo">
	   <!-- Injecting the value of message property using constructor method -->
	   <constructor-arg name="topicName" value="Welcome To AshokIT For Spring Framework"/>
   </bean>  
   
     <!--configuring the Java Class as spring Beab -->
   <bean id="st" class="com.ashokit.spring.beans.Student">
	   <property name="id" value="123"/>
	   <property name="name" value="Mahesh"/>
	   <property name="course" value="SBMS"/>
	   <property name="fee" value="8000"/>
	   <property name="emails">
		   <array>
			   <value>mahesh.ashokit@gmail.com</value>
			   <value>ashokit.mahesh@gmail.com</value>
		   </array>
	   </property>
	   <property name="contactNos">
		   <list>
			   <value>1121121212121</value>
			   <value>1232323232323</value>
		   </list>
	   </property>
   </bean>      
       
</beans>       


App.java
========
package com.ashokit;

import org.springframework.beans.factory.BeanFactory;
import org.springframework.beans.factory.xml.XmlBeanFactory;
import org.springframework.core.io.ClassPathResource;
import org.springframework.core.io.Resource;

import com.ashokit.spring.beans.Demo;
import com.ashokit.spring.beans.Student;
import com.ashokit.spring.beans.Welcome;

public class App 
{
    public static void main( String[] args )
    {
        //Finding the location of Spring Configuration file
    	//Resource(I) and Implementation class(ClassPathResource,FileSystemResource)
    	//ClassPathResource is used to find the spring configuration file from classpath itself
    	//FileSystemResource is used to find the spring configuration file from our file system
    	Resource resource = new ClassPathResource("com/ashokit/spring/config/spring.xml");
    	
    	//Activating the BeanFactory Container
    	BeanFactory factory = new XmlBeanFactory(resource);
    	
    	//Request the Spring Bean object from spring container by passing id of spring bean
    	Welcome welcomeBean = (Welcome) factory.getBean("wb");//Requesting by identity
    	Welcome welcomeBean1 = (Welcome) factory.getBean("wb");
    	System.out.println("WelcomeBean:::::::" + welcomeBean.hashCode() + "-----" + welcomeBean1.hashCode());
    	Demo demoBean = (Demo) factory.getBean("db");//Requesting by identity
    	Demo demoBean1 = (Demo) factory.getBean("db");
    	System.out.println("Demo::::" + demoBean.hashCode() +"------"+demoBean1.hashCode());
    	Student st = factory.getBean(Student.class);//Requesting by Type of Object
    	System.out.println(st);
    	Student st1 = factory.getBean(Student.class, "st");//Requesting by Type of object with id 
    	System.out.println(st1);
    	//printing the spring beans information
    	System.out.println(welcomeBean);
    	System.out.println(demoBean);
    }
}

OUTPUT
======
Spring Bean Welcome Clas....
Setter Method called from Welcome Class
WelcomeBean:::::::1072410641-----1072410641
Demo Class Constructor
Demo::::1164107853------1164107853
Student Class Non-parameterized Constructor....
Student [id=123, name=Mahesh, course=SBMS, fee=8000.0, emails=[mahesh.ashokit@gmail.com, ashokit.mahesh@gmail.com], contactNos=[1121121212121, 1232323232323]]
Student [id=123, name=Mahesh, course=SBMS, fee=8000.0, emails=[mahesh.ashokit@gmail.com, ashokit.mahesh@gmail.com], contactNos=[1121121212121, 1232323232323]]
Welcome [message=Welcome To AshokIT For Spring Framework]
Demo [topicName=Welcome To AshokIT For Spring Framework]



SpringClient.java
=================
package com.ashokit;

import org.springframework.beans.factory.support.DefaultListableBeanFactory;
import org.springframework.beans.factory.xml.XmlBeanDefinitionReader;

import com.ashokit.spring.beans.Demo;
import com.ashokit.spring.beans.Student;

public class SpringClient {
	
	public static void main(String[] args) {
		
		//creating the IOC container 
		DefaultListableBeanFactory factory = new DefaultListableBeanFactory();
		
		//Loading spring configuration file
		XmlBeanDefinitionReader reader = new XmlBeanDefinitionReader(factory);
		reader.loadBeanDefinitions("com/ashokit/spring/config/spring.xml");
		
		//Getting the Spring Bean Objects
		Student st = factory.getBean(Student.class);
		System.out.println(st);
		Demo db  = (Demo)factory.getBean("db");
		System.out.println(db);
	}
}

OUTPUT
======
Student Class Non-parameterized Constructor....
Student [id=123, name=Mahesh, course=SBMS, fee=8000.0, emails=[mahesh.ashokit@gmail.com, ashokit.mahesh@gmail.com], contactNos=[1121121212121, 1232323232323]]
Demo Class Constructor
Demo [topicName=Welcome To AshokIT For Spring Framework]

Different ways for Requesting Spring Bean Object
================================================
1) factory.getBean("id")  >>> Object

2) factory.getBean(ClassType) >>>>> class object

3) factory.getBean(classType,"id") >>>> class object
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