Spring : init-method and destroy-method

In this first example, I’ll show you how the lifecycle of a bean happens within the xml-configfile.

In the xml-file, we can define an init- and destroy-method to the bean, which will be called automatically by Spring.
Config.xml

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"       
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"      
 xmlns:context="http://www.springframework.org/schema/context"       
xsi:schemaLocation="http://www.springframework.org/schema/beans            
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd">    
<!-- -->
<bean id="attributesTest" class="a.Test" init-method="initMethod" 
            destroy-method="destroyMethod">    
</bean>

</beans>

 

Now consider our bean with these 2 methods into it:

 

public class LifeCycledBean2{    
//
        public LifeCycledBean2(){        
            System.out.println("We are in the constructor of LifeCycledBean2");    
        }    
        public void initMethod()
         {        
            System.out.println("We are in initMethod of LifeCycledBean2");    
         }    
        public void destroyMethod()
        {        
            System.out.println("We are in destroyMethod of Test");    
        }
}

Main or Runner program
In this case, I’ll use AbstractApplicationContext because this Context has a function to destroy the Context which a normal ApplicationContext doesn’t have.

import org.springframework.context.support.AbstractApplicationContext;
import org.springframework.context.support.ClassPathXmlApplicationContext;
public class JustATest {    
public static void main(String[] args) {        
            AbstractApplicationContext ctx = new ClassPathXmlApplicationContext("Config.xml");       
            ctx.registerShutdownHook();        
            Test test =  ctx.getBean("attributesTest",Test.class);    
        }
}

The output will be:

We are in the constructor of Test
We are in initMethod of Test
We are in destroyMethod of Test

It’s also possible to declare default init- and destroy-methods in the xml-file. This is done in the beans-tag:

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"       
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"       
xmlns:context="http://www.springframework.org/schema/context"       
xsi:schemaLocation="http://www.springframework.org/schema/beans            
http://www.springframework.org/schema/beans/spring-beans-3.0.xsd"       
default-init-method="initMethod"       
default-destroy-method="destroyMethod"
>
...