@PostConstruct and @PreDestroy Annotations in JSR-250 with Spring

Circle.java

package com.dineshonjava.sdnext.jsr.tutorial;

import javax.annotation.PostConstruct;
import javax.annotation.PreDestroy;
import javax.annotation.Resource;

public class Circle
{ 
 private Point center;
 
 @Resource(name="pointB")
 public void setCenter(Point center) 
 {
     this.center = center;
 }
 
 public void draw() 
 {
System.out.println("Circle is drawn of center ("+center.getX()+", "+center.getY()+")");
 }
 
 @PostConstruct
 public void initializeCircle()
 {
     //populates the circle data cache upon initialization...  
     System.out.println("Init of Circle");
 }
 
 @PreDestroy
 public void destroyCircle()
 {
    //clears the circle related cache upon destruction..  
    System.out.println("Destroy of Circle");
 }
}

Point.java

package com.dineshonjava.sdnext.jsr.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;
 }
}

DrawingApp.java

package com.dineshonjava.sdnext.jsr.tutorial;

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

/**
 * @author Dinesh
 *
 */
public class DrawingApp 
{
 /**
  * @param args
  */
 public static void main(String[] args) 
 {
AbstractApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
context.registerShutdownHook();
Circle circle = (Circle) context.getBean("circle");
circle.draw();
 }
}

spring.xml

<beans xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:>
2. Using <context:annotation-config  />
spring.xml
<beans xmlns:aop="http://www.springframework.org/schema/aop" xmlns:context="http://www.springframework.org/schema/context" xmlns:p="http://www.springframework.org/schema/p" xmlns:>
Once you are done with creating source and bean configuration files, let us run the application. If everything is fine with your application, this will print the following message:





Output:
Jul 14, 2012 1:57:00 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@145d068: startup date [Sat Jul 14 01:57:00 IST 2012]; root of context hierarchy
Jul 14, 2012 1:57:00 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring.xml]
Jul 14, 2012 1:57:00 AM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@4e79f1: defining beans [circle,pointA,pointB,pointC,center,org.springframework.context.annotation.internalConfigurationAnnotationProcessor,org.springframework.context.annotation.internalAutowiredAnnotationProcessor,org.springframework.context.annotation.internalRequiredAnnotationProcessor,org.springframework.context.annotation.internalCommonAnnotationProcessor,org.springframework.context.annotation.ConfigurationClassPostProcessor$ImportAwareBeanPostProcessor#0]; root of factory hierarchy
Init of Circle

Circle is drawn of center (-20, 0)

Destroy of Circle