How to set a default method to running code on the creation or destruction of a bean

In the post Executing code on the creation or destruction of a bean in Spring I explain three ways to execute code on the creation or destruction of a Bean in Spring.
With two of these ways you can set the execution of a specific custom method:

• with the annotations @PostConstruct and @PreDestroy
• configuring the properties init-method and destroy-method

There is a very convenient way in the case that more beans have methods with the same name to be executed on their creation and destruction, i.e. you can specify a default method for all the beans.

For example see the following java project:

1. create the file conf/app-context.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-3.1.xsd
           http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-3.1.xsd"
       default-lazy-init="true"
       default-init-method="defaultInit"
       default-destroy-method="defaultDestroy" >
   
   	<context:annotation-config/>
   
       <bean id="simpleBean" class="eu.lucazanini.mybean.SimpleBean" 
   	scope="singleton" />
   
   </beans>
   

   where the default methods are set in the highlighted lines;
   the folder “conf” must be in the classpath

2. create the file conf/log4j.xml

   <?xml version="1.0" encoding="UTF-8"?>
   <!DOCTYPE log4j:configuration PUBLIC "-//LOGGER" "log4j.dtd">
   
   <log4j:configuration xmlns:log4j="http://jakarta.apache.org/log4j/"> 
       <appender name="stdout" class="org.apache.log4j.ConsoleAppender">
           <layout class="org.apache.log4j.PatternLayout">
               <param name="ConversionPattern" value="%d %-5p %c{1}:%L %m %n" />
   <!--
   ConversionPattern format specification
   %d      inserts the date; you can specify the format (%d{yyyy-MM-dd HH:mm:ss,SSS})
   %-5p    inserts the priority log level, 5 characters, left justified
   %c{1}   inserts the name of the class
   %L      inserts the line number
   %m      inserts the user message
   %n      inserts the separator (for example, a new line)
   -->
           </layout>
       </appender>
   
       <appender name="fileAppender" class="org.apache.log4j.RollingFileAppender">
       	<param name="append" value="false" />
           <param name="Threshold" value="DEBUG" />
           <param name="File" value="logs/app.log"/>
           <param name="MaxFileSize" value="512KB" />
           <param name="MaxBackupIndex" value="10" />
           <layout class="org.apache.log4j.PatternLayout">
               <param name="ConversionPattern" value="%d %-5p %c{1}:%L %m %n" />
           </layout>
       </appender>
   
   <!--sets the priority log level for org.springframework-->
       <logger name="org.springframework">
           <level value="info"/>
       </logger>
   
   <!--sets the priority log level for eu.lucazanini-->
       <logger name= "eu.lucazanini">
           <level value="debug"/>
       </logger>
   
   <!--sets the default priority log level-->
       <root>
           <priority value="debug"></priority>
           <appender-ref ref="stdout"/>
           <appender-ref ref="fileAppender"/>
       </root>
   </log4j:configuration>
   

3. create the file eu/lucazanini/mybean/Main.java

   package eu.lucazanini.mybean;
   
   import org.apache.log4j.Logger;
   import org.springframework.context.support.*;
   
   public class Main {
   
       private static org.apache.log4j.Logger log = Logger.getLogger(Main.class);
   
       public static void main(String[] args) {
   
   	GenericXmlApplicationContext ctx = new GenericXmlApplicationContext();
   	ctx.load("classpath:app-context.xml");
   	ctx.refresh();
   
   	log.debug("creating bean");
   	SimpleBean bean = (SimpleBean) ctx.getBean("simpleBean");
   	log.debug("created bean");
   
   	log.debug("destroying bean");
   	ctx.destroy();
   	
   	log.debug("destroyed bean");
   
   	log.debug("application shutdown");
       }
   }
   

4. create the file eu/lucazanini/mybean/SimpleBean.java

   package eu.lucazanini.mybean;
   
   import org.apache.log4j.Logger;
   
   public class SimpleBean {
   
       private static org.apache.log4j.Logger log = Logger
   	    .getLogger(SimpleBean.class);
   
       public SimpleBean() {
   	log.debug("constructor");
       }
   
       public void defaultInit() {
   	log.debug("defaultInit-method");
       }
   
       public void defaultDestroy() {
   	log.debug("defaultDestroy-method");
       }
   
   }
   

   where the default methods are highlighted

The output is the following:

...
DEBUG Main:[...] creating bean 
DEBUG SimpleBean:[...] constructor 
DEBUG SimpleBean:[...] defaultInit-method 
DEBUG Main:[...] created bean 
DEBUG Main:[...] destroying bean 
...
DEBUG SimpleBean:[...] defaultDestroy-method 
DEBUG Main:[...] destroyed bean 
DEBUG Main:[...] application shutdown