Why spring init-method destroy-method methods behaving different?

Question

I am new to springs. I am trying to call init and destroy method for different bean invoking

My init method is called from only "FileSystemResource" Why it was not called from others?

public class DefaultMessage {
    private String message = "Basic Bean injecting";

    public String getMessage() {
        return message;
    }

    public void setMessage(String message) {
        this.message = message;
    }

    public DefaultMessage(String message) {
        this.message = message;
    }

    public DefaultMessage() {
    }
    public void init(){
        System.out.println("Testing init.");
    }
    public void destory(){
        System.out.println("Spring Container is destroyed.");
    } 

My XML is

<bean id="basicBean" class="com.sarma.spring.core.DefaultMessage" init-method="init" destroy-method="destory"></bean>

Main class

//Type 1
ApplicationContext applicationContext =new ClassPathXmlApplicationContext("DefaultMessage.xml");

//Basic Bean Testing
DefaultMessage message = (DefaultMessage) applicationContext.getBean("basicBean");
log.info(message.getMessage());
log.info("---------------------------ApplicationContext End------------------------------");

//Type 2
Resource res = new FileSystemResource("C:\\Sarma\\Spring\\SpringEx\\src\\resource\\DefaultMessage.xml");
BeanFactory factory = new XmlBeanFactory(res);
DefaultMessage message1 = (DefaultMessage) factory.getBean("basicBean");
log.info("Test "+message1.getMessage());
log.info("- ---------------------------FileSystemResource End------------------------------");  

//Type 3
ClassPathResource res1 = new ClassPathResource("DefaultMessage.xml");
BeanFactory factory1 = new XmlBeanFactory(res1);
DefaultMessage message2 = (DefaultMessage) factory1.getBean("basicBean");
log.info("Test "+message2.getMessage());
log.info("- ---------------------------ClassPathResource End-------------------------------");

//Type4
ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"DefaultMessage.xml"});
DefaultMessage message3 = (DefaultMessage) context.getBean("basicBean");
log.info(message3.getMessage());
context.close();
log.info("- ---------------------------ConfigurableApplicationContext End------------------");

OUTPUT

2013-09-18 13:49:22 INFO  ClassPathXmlApplicationContext:513 - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@913750: startup date [Wed Sep 18 13:49:22 EDT 2013]; root of context hierarchy
2013-09-18 13:49:22 INFO  XmlBeanDefinitionReader:316 - Loading XML bean definitions from class path resource [DefaultMessage.xml]
2013-09-18 13:49:22 INFO  DefaultMessageMain:27 - Basic Bean injecting
2013-09-18 13:49:22 INFO  DefaultMessageMain:29 - ---------------------------ApplicationContext End------------------------------
2013-09-18 13:49:22 INFO  XmlBeanDefinitionReader:316 - Loading XML bean definitions from file [C:\Sarma\Spring\SpringEx\src\resource\DefaultMessage.xml]
Testing init.
2013-09-18 13:49:22 INFO  DefaultMessageMain:36 - Test Basic Bean injecting
2013-09-18 13:49:22 INFO  DefaultMessageMain:37 - - ---------------------------FileSystemResource End------------------------------
2013-09-18 13:49:22 INFO  XmlBeanDefinitionReader:316 - Loading XML bean definitions from class path resource [DefaultMessage.xml]
2013-09-18 13:49:22 INFO  DefaultMessageMain:42 - Test Basic Bean injecting
2013-09-18 13:49:22 INFO  DefaultMessageMain:43 - - ---------------------------ClassPathResource End-------------------------------
2013-09-18 13:49:22 INFO  ClassPathXmlApplicationContext:513 - Refreshing org.springframework.context.support.ClassPathXmlApplicationContext@176e552: startup date [Wed Sep 18 13:49:22 EDT 2013]; root of context hierarchy
2013-09-18 13:49:22 INFO  XmlBeanDefinitionReader:316 - Loading XML bean definitions from class path resource [DefaultMessage.xml]
2013-09-18 13:49:22 INFO  DefaultMessageMain:47 - Basic Bean injecting
2013-09-18 13:49:22 INFO  ClassPathXmlApplicationContext:873 - Closing org.springframework.context.support.ClassPathXmlApplicationContext@176e552: startup date [Wed Sep 18 13:49:22 EDT 2013]; root of context hierarchy
2013-09-18 13:49:22 INFO  DefaultMessageMain:49 - - ---------------------------ConfigurableApplicationContext End------------------

My init method is called from only "FileSystemResource" Why it was not called from others?

Why it is behaving different?

It never called my destroy method

Answer 1

For ClassPathXmlApplicationContext, we can pass different xml's for example

ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"DefaultMessage.xml", "DefaultMessage1.xml}");

while closing ConfigurableApplicationContext it will close all resource which was opened, that why it closed all 3 FileSystemResource, ClassPathResource, ClassPathXmlApplicationContext.

Answer 2

I have implemented DisposableBean interface to my bean class and overrides destroy method and removed destroy-method method form my XML.

Now destroy method is calling 3 times except ApplicationContext, Destroy method is calling from FileSystemResource, ClassPathResource, ClassPathXmlApplicationContext and not from ApplicationContext.

Answer 3

I'm going to copy your code to explain

//Type 1
ApplicationContext applicationContext =new ClassPathXmlApplicationContext("DefaultMessage.xml");

//Basic Bean Testing
DefaultMessage message = (DefaultMessage) applicationContext.getBean("basicBean");

The above will init() your bean.

//Type 2
Resource res = new FileSystemResource("C:\\Sarma\\Spring\\SpringEx\\src\\resource\\DefaultMessage.xml");
BeanFactory factory = new XmlBeanFactory(res);
DefaultMessage message1 = (DefaultMessage) factory.getBean("basicBean");

This will also init() your bean.

//Type 3
ClassPathResource res1 = new ClassPathResource("DefaultMessage.xml");
BeanFactory factory1 = new XmlBeanFactory(res1);
DefaultMessage message2 = (DefaultMessage) factory1.getBean("basicBean");

This will also init() your bean.

//Type4
ConfigurableApplicationContext context = new ClassPathXmlApplicationContext(new String[] {"DefaultMessage.xml"});
DefaultMessage message3 = (DefaultMessage) context.getBean("basicBean");
log.info(message3.getMessage());
context.close();

This will also init() your bean. Because of the context.close(), all beans will be destroyed before the context being closed. If the destroy-method isn't being called, you can try with DisposableBean interface, but consider that bad practice as your classes start being dependent on Spring types.