Default initialization & destroy methods in Spring Framework
Spring container has features that it can auto detect your initialization and Destroy method if you follow same coding convention in project.
Destroy method callbacks are also similarly use the 'default-destroy-method'.
<bean id="sampleService" class="org.abc.DefaultSample">
<property name="samplename" ref="sampleName" />
Attribute on the top-level <beans/> element. So Spring IoC container will recognize a method called 'init' on beans as being the initialization method callback, and when a bean is being created and assembled, if the bean's class has such a method, it will be invoked at the appropriate time.