Dinesh on Java

.....
// create BeanFactory
ConfigurableBeanFactory  factory = new XmlBeanFactory(new FileSystemResource("spring.xml"));
// now register some beans
// now register any needed BeanPostProcessors
DisplayNameBeanPostProcessor postProcessor = new DisplayNameBeanPostProcessor(); 
factory.addBeanPostProcessor(postProcessor);
.....
// now start using the factory

Lets see the following example which describe the BeanPostProcessor activity…
DisplayNameBeanPostProcessor.java

package com.dineshonjava.sdnext.beanPostProcessor.tutorial;

import org.springframework.beans.BeansException;
import org.springframework.beans.factory.config.BeanPostProcessor;

public class DisplayNameBeanPostProcessor implements BeanPostProcessor 
{  
@Override
public Object postProcessAfterInitialization(Object bean, String beanName) throws BeansException 
{
System.out.println("In After bean Initialization method. Bean name is "+beanName);
return bean;
}

@Override
public Object postProcessBeforeInitialization(Object bean, String beanName) throws BeansException 
{
System.out.println("In Before bean Initialization method. Bean name is "+beanName);
return bean;
}
}

Triangle.java

package com.dineshonjava.sdnext.beanPostProcessor.tutorial;

public class Triangle
{
 private Point pointA;
 private Point pointB;
 private Point pointC;
 /**
  * @param pointA the pointA to set
  */
 public void setPointA(Point pointA) {
  this.pointA = pointA;
 }

 /**
  * @param pointB the pointB to set
  */
 public void setPointB(Point pointB) {
  this.pointB = pointB;
 }

 /**
  * @param pointC the pointC to set
  */
 public void setPointC(Point pointC) {
  this.pointC = pointC;
 }

 public void draw()
 {
System.out.println("PointA is ("+pointA.getX()+", "+pointA.getY()+")");
System.out.println("PointB is ("+pointB.getX()+", "+pointB.getY()+")");
System.out.println("PointC is ("+pointC.getX()+", "+pointC.getY()+")");
 }
}

Point.java

package com.dineshonjava.sdnext.beanPostProcessor.tutorial;

public class Point
{
 private int x;
 private int y;
 /**
  * @return the x
  */
 public int getX() {
  return x;
 }
 /**
  * @param x the x to set
  */
 public void setX(int x) {
  this.x = x;
 }
 /**
  * @return the y
  */
 public int getY() {
  return y;
 }
 /**
  * @param y the y to set
  */
 public void setY(int y) {
  this.y = y;
 }
}

spring.xml

<beans xmlns:aop="http://www.springframework.org/schema/aop" xmlns:p="http://www.springframework.org/schema/p" xmlns:>
If every thing is OK now run the following class file and see the result on console.
DrawingApp.java
package com.dineshonjava.sdnext.beanPostProcessor.tutorial;

import org.springframework.context.ApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;

/**
 * @author Dinesh Rajput
 *
 */
public class DrawingApp 
{
 /**
  * @param args
  */
 public static void main(String[] args) 
 {
ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
Triangle triangle = (Triangle) context.getBean("triangle");
triangle.draw();
 }
}

 

Output:
Jul 2, 2012 11:28:23 PM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@ab50cd: startup date [Mon Jul 02 23:28:23 IST 2012]; root of context hierarchy
Jul 2, 2012 11:28:23 PM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring.xml]
Jul 2, 2012 11:28:23 PM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@14c1103: defining beans [triangle,pointA,pointB,pointC,com.sdnext.beanPostProcessor.tutorial.DisplayNameBeanPostProcessor#0]; root of factory hierarchy
In Before bean Initialization method. Bean name is pointA
In After bean Initialization method. Bean name is pointA
In Before bean Initialization method. Bean name is pointB
In After bean Initialization method. Bean name is pointB
In Before bean Initialization method. Bean name is pointC
In After bean Initialization method. Bean name is pointC
In Before bean Initialization method. Bean name is triangle

In After bean Initialization method. Bean name is triangle

PointA is (0, 0)

PointB is (-20, 0)

PointC is (20, 0)