Java Questions

Encapsulation is a process of binding the data objects together under a single unit.It is one ofthe elements of oops

- A process is an execution of a program, while a Thread is a single execution sequence within a process.

- A process can contain multiple threads. A Thread is sometimes called a lightweight process.

The Java programming language provides a system-level thread to track memory allocation.

Garbage collection has the following characteristics:

• Checks for and frees memory no longer needed

• Is done automatically

• Can vary dramatically across JVM implementations

• An Interpreter is a program that reads in as input a source program, along with data for the program, and translates the source program step by step.

The Java interpreter decodes each lines bytecode and runs a series of machine instructions for that bytecode. The JVM takes the byte code and generates machine code. The byte code is compiled to machine code, and the machine code is executed.

Overridden methods must have the same name, argument list, and return type (i.e., they must have the exact signature of the method we are going to override, including return type.)

The overriding method cannot be less visible than the method it overrides( i.e., a public method cannot be override to private).

The overriding method may not throw any exceptions that may not be thrown by the overridden method

A Monitor defines a lock and condition variables for managing concurrent access to shared data. The monitor uses the lock to ensure that only a single thread inactive in the monitor code at any time.

A monitor allows only one thread to lock an object at once.

The object need to be serialized when it’s sent over a network and when it’s state is saved. Exceptions which occur during serialization are:

a. transient fields

b. when the base class is serialized then only base class fields are handled.

c. static fields are ignored because they are not part of any state.