ApplicationContext in Spring

In previous we used Bean Factory container and discussed with example. Now we will discuss about the Application Context and Using with in Example.
Application Context Just like as Bean Factory's Big Brother with some additional functionality such as AOP concept, event notification and it adds more enterprise-specific functionality such as the ability to resolve textual messages from a properties file and the ability to publish application events to interested event listeners. This container is defined by the org.springframework.context.ApplicationContext interface.

The ApplicationContext includes all functionality of the BeanFactory, it is generally recommended over the BeanFactory. BeanFactory can still be used for light weight applications like mobile devices or applet based applications.

The most commonly used ApplicationContext implementations are:
  • FileSystemXmlApplicationContext: This container loads the definitions of the beans from an XML file. Here you need to provide the full path of the XML bean configuration file to the constructor.
  • FileSystemXmlApplicationContext context = new FileSystemXmlApplicationContext("F:/my workspace/springAppDemo/src/spring.xml");
    
    Using wildcard for file system:
    FileSystemXmlApplicationContext context = new FileSystemXmlApplicationContext("F:/*my workspace*/**/src/*-spring.xml");
    
  • ClassPathXmlApplicationContext This container loads the definitions of the beans from an XML file. Here you do not need to provide the full path of the XML file but you need to set CLASSPATH properly because this container will look bean configuration XML file in CLASSPATH.
  • ApplicationContext context = new ClassPathXmlApplicationContext("classpath:com/dineshonjava/sdnext/springConfig/spring.xml");  
    
    Using wildcard for claspath:
    ApplicationContext context = new ClassPathXmlApplicationContext("classpath*:com/dineshonjava/**/springConfig/spring.xml");
    
    ApplicationContext context = new ClassPathXmlApplicationContext("classpath*:com/*/**/springConfig/*-spring.xml");
    
  • WebXmlApplicationContext: This container loads the XML file with definitions of all beans from within a web application.
  • ApplicationContext appContext = WebApplicationContextUtils.getWebApplicationContext(servletContext);
    
ApplicationContext in Spring


Let us see Example.
Triangle.java
package com.sdnext.dineshonjava.applicationcontext.tutorial;

public class Triangle 
{
 private String type;
 
 /**
  * @param type the type to set
  */
 public void setType(String type)
 {
  this.type = type;
 }

 public void draw()
 {
  System.out.println(type+" Triangle Drawn");
 }
}

spring.xml
<beans xmlns:aop="http://www.springframework.org/schema/aop" xmlns:p="http://www.springframework.org/schema/p" xmlns:security="http://www.springframework.org/schema/security" xmlns:tx="http://www.springframework.org/schema/tx" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns="http://www.springframework.org/schema/beans" xsi:schemalocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.5.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd
     http://www.springframework.org/schema/security http://www.springframework.org/schema/security/spring-security-2.0.4.xsd 
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop-2.5.xsd 
  http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx-2.5.xsd">
  
  <bean class="com.sdnext.applicationcontext.tutorial.Triangle" id="triangle">
    <property name="type" value="Equilateral"></property>
  </bean>
</beans>
DrawingApp.java
package com.sdnext.dineshonjava.applicationcontext.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) 
 {
  //Triangle triangle = new Triangle();
  //BeanFactory factory =new XmlBeanFactory(new FileSystemResource("spring.xml"));
 ApplicationContext context = new ClassPathXmlApplicationContext("spring.xml");
  Triangle triangle = (Triangle) context.getBean("triangle");
  triangle.draw();
 }
}
Now run the example:
Output:
Jun 18, 2012 11:40:04 AM org.springframework.context.support.AbstractApplicationContext prepareRefresh
INFO: Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@145d068: startup date [Mon Jun 18 11:40:04 IST 2012]; root of context hierarchy
Jun 18, 2012 11:40:04 AM org.springframework.beans.factory.xml.XmlBeanDefinitionReader loadBeanDefinitions
INFO: Loading XML bean definitions from class path resource [spring.xml]
Jun 18, 2012 11:40:05 AM org.springframework.beans.factory.support.DefaultListableBeanFactory preInstantiateSingletons
INFO: Pre-instantiating singletons in org.springframework.beans.factory.support.DefaultListableBeanFactory@14c1103: defining beans [triangle]; root of factory hierarchy
Equilateral Triangle Drawn


In Next Chapter we will discuss about Injecting of Constructor and Object in Application.
                                          
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