Enterprise JavaBeans go through different states in their life cycle. Each type of EJB has different states. States specific to each type of EJB are discussed in the next sections.
We can annotate methods in session beans so that they are automatically invoked by the EJB container at certain points in the bean's life cycle. For example, we could have a method invoked right after the bean is created or right before it is destroyed.
Before explaining the annotations available to implement life cycle methods, a brief explanation of the session bean life cycle is in order. The life cycle of a stateful session bean is different from the life cycle of a stateless or singleton session bean.
A stateful session bean life cycle contains three states: Does Not Exist, Ready, and Passive:
Before a stateful session bean is deployed, it is in the Does Not Exist state. Upon successful deployment, the EJB container does any required dependency injection...