How to create BeanFactory using XmlBeanFactory in Spring Framework ?.

A simple example demonstrating the working of BeanFactory using XmlBeanFactory in Spring Framework

1. Create a normal class having a method say 'Dog' -

package com.hubberspot.spring;


public class Dog {

 public void move() {
  System.out.println("Dog moving ...");
 }

}

2. Create a spring.xml file placed in root of your application -

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<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE beans PUBLIC "-//SPRING//DTD BEAN 2.0//EN" 
"http://www.springframework.org/dtd/spring-beans-2.0.dtd">

<beans>

 <!-- In order to create an object of bean we define its properties in bean 
  tag. The 'id' attribute value can be thought of as a reference to 'class' 
  attribute value -->
 <bean id="dog" class="com.hubberspot.spring.Dog" />

</beans>

3. Create a Test class for the application (imp) -

package com.hubberspot.spring;

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


public class WildLifeApplication {

 public static void main(String[] args) {

  // BeanFactory is a Spring bean factory which 
  // provides us with the object requested
  // it reads the configuration file and provides
  // us with the necessary object required
  // We are using XmlBeanFactory because this 
  // bean factory reads the xml file while preparing
  // its objects. We provide XmlBeanfactory with a 
  // configuration file called as spring.xml placed
  // at root of our application. It is passed to first
  // FileSystemResource object which provides the
  // XmlBeanFactory with the configuration resource
  BeanFactory factory = new XmlBeanFactory(
    new FileSystemResource("spring.xml"));

  // In order to get a object instantiated for a particular
  // bean we call getBean() method of BeanFactory passing it the
  // id for which the object is to be needed. Here getBean() 
  // returns an Object. We need to cast it back to the Dog object
  // without implementing new keyword we have injected object of 
  // Dog just by reading an xml configuration file.
  Dog dog = (Dog)factory.getBean("dog");

  // Calling our functionality
  dog.move();

 }

}

Output of the program :