Java Questions

:: is the scope resolution operator. When local variable and global variable are having same name, local variable gets the priority. C++ allows flexibility of accessing both the variables through a scope resolution operator

ClassName refName = new ClassName();

or

ClassName refName;

refName = new ClassName();

Constructor chaining is the process of calling one constructor from another constructor with respect to current object.

Within same class: It can be done using this() keyword for constructors in same class

From base class: by using super() keyword to call constructor from the base class.

When creating a thread by extending the Thread class, it is not mandatory to override the run method (If we are not overriding the run method , it is useless), because Thread class have already given a default implementation for run method. But if we are implementing Runnable , it is mandatory to override the run method. The preferred way to create a thread is by implementing Runnable interface, because it give loose coupling.

This is a keyword and used as reference to Current object address in java. 

It means by using which object the method is called that object hashcode is stored inside the 'this'.

The create method in a stateless bean cannot have arguments, and can only have a single method called create(). While create in Stateful bean can have arguments and could be any method starting with create string eg. create(arg1, arg2, ...). Although it is not compiler checked but in stateless bean the ejb Passivate() and ejb Active() methods has to be empty as these functions are never called by EJB container. As conceptually in stateful session bean we might need to store the clients information hence arguments in createare necessary. While in stateless bean we don't hence no arguments are necessary. It's intutive isn't intutive isn't. I my life I haven't seen such a futuristic server programming tool as EJB.

A method declared as final can't be overridden. A sub-class can't have the same method signature with a different implementation.

By using method.

The method used to get the data is called getter method.