Learning Java

Static methods in java belong to the class (not an instance of it). They use no instance variables and will usually take input from the parameters, perform actions on it, then return some result. 

Instances methods are associated with objects and, as the name implies, can use instance variables.


My Observation:
 If you try to invoke a static method using an instance object, you only get a warning that static method must be accessed in  a static way . Code will still run.  


An abstract class can have method implementations.
 
An abstract method does not have any implementation.
Serialization will convert the object into byte array and that can be saved  on disk which can be deserialized later . 

EJB is a part of JAVA EE or J2EE (Enterprise edition) .
J2SE is the standard edition of JAVA.
Hibernate is the open source api developed in Java only .
Basically in EJB , you have a remote interface ( to call the EJB remotely ) ,
a local interface or Home interface  ( to call the EJB locally ) and an implementation class.

A message driven bean only has an implementation class.

All the three Enterprise Java Bean's namely session bean, entity bean and message driven beans are collectively called as Enterprise beans as well .