Immutable classes in Java

1. Immutable objects are those whose state cannot change after construction
2. Examples: Integer and String
3. Features
1. Simple to construct, test, and us
2. Automatically thread safe  - No synchronization issue
3. No need of copy construction
4. No need of hash implementation
4. How to make a class as immutable:
1. Make sure that it cannot be inherited. Make it final.
2. Keep constructor private.
3. Make fields as final or private.
4. No set methods to change the state of the object

Example:

 
Public final class Shape {
 Private final int I;
 Private final double j;

 Public Shape(double a, int b) {
  I = a;
  J = b;
 }

 Public int getI() {
  Return I;
 }

 Public double getJ() {
  Return j;
 }

Java Concepts

Java String concepts

Serialization & Deserialization

Jersey Package Dependencies

Observable and Observer Interface

Servlet Filter

Servlet Client Request

Spring dependencies for Maven

Java String Operations