Languages-Java (3i Infotech Papers): Sample Questions 1 - 2 of 141

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Answer

Explanation

• A stateful session bean is a type of enterprise bean, which preserve the conversational state with client.

• A stateful session bean as per its name keeps associated client state in its instance variables.

  • The home interfaces create session bean instance defining the create method for bean.

  • Remote interfaces provide business methods- EJB container intercepts method invocations calling the respective bean implementation method, or, in the case of create () with a stateless session bean, gets a bean instance from the pool (if possible).

• EJB Container creates a separate stateful session bean to process client’s each request.

• Each call from the client to the bean is a remote invocation using the Java Remote Method Invocation (RMI) API- argument parameters and return values are copied, serialized, and transmitted remotely.

  Remote calls give enterprise application scalability and accessibility but add network overhead.

» Languages » Java

Explanation

• Ability of an object to take on many forms is polymorphism.

• Common use of polymorphism in OOP is for parent class to refer to a child class object- implements the concept of performing a single action by different ways.

• There are two types of polymorphism in java: compile time polymorphism and runtime polymorphism.

• Polymorphism in java can be done by method overloading or by method overriding.

• Overloading static method in java is an example of compile time polymorphism.