Encapsulation in Java is a core concept in object-oriented programming (OOP ) concept which combine data and the functions that work on data into a single unit like class. Encapsulation is also known as data hiding because it restricts the direct access to the internal state of an object by protecting data from unauthorized access .
HOW ENCAPSULATION IS ACHIEVED IN JAVA
Encapsulation is achieved in Java by using :
- Private data members
- Public getter and setter methods
Key Rules for Java Encapsulation:
- Declare variable or data as private : By declaring data as a private prevents any outside class from accessing the data fields directly.
- Provide public getter and setter methods : These methods in encapsulated class provide controlled access to the private variables .
Getter methods retrieve the value of a variable (e.g. , getValue() ).
Setter methods set or update the value of a variable (e.g., setAmount(” $500″ ).
Example :
public class Gift {
//Declaring data variables as private
private String giftName;
private int score;
//public getter method for giftName
public String getgiftName(){
return giftName;
}
//public setter method for giftName
public void setgiftName ( String newName){
this.giftName=newName;
}
//public getter method for score
public int getScore () {
return score;
}
//public setter method for score with validation
public void setScore ( int newScore) {
if ( newScore>90 && newScore<101) {
this.score = newScore ;
} else {
System.out.println(“Invalid score “);
}
}
public class DemoEncapsulation {
public static void main (String args[] ) {
Gift gif =new Gift ();
//Set values using setter methods
gif.setgiftName(” $500″);
gif.setScore(95);
// Get values using getter methods and print
System.out.println(” Giftname : “ + gif.getgiftName());
System.out.println(“Score : “ + gif.getScore());
}
}
OUTPUT:
Giftname : $500
Score : 95
Advantages of Encapsulation :
- Easy Maintainability : By using encapsulation , changes to internal implementation can be made without affecting external code that uses the class .
- Data Hiding : Java Encapsulation restricts direct access to class variables , protecting sensitive data from unauthorized access .
- Enhanced Security : Encapsulation allows control and validation over data , preventing invalid values to be set.
- Code Reusability : Java Encapsulated classes can be reused in different programs without exposing internal logic .
- Better Modularity : Encapsulation enhance organized , modular code by keeping data and methods together within a class .
Disadvantages of Encapsulation :
- Performance Overhead : In Java Encapsulated class by accessing data through methods instead of directly accessing can cause a minor performance cost, basically in performance-critical applications .
- Increased Code Complexity : In Java Encapsulation class by writing getter and setter methods for every variable can make the code longer and sometimes more complex .
- Less Flexibility in Some Cases : In Java encapsulated class , over restricting access to class members may limit the ability of other classes to extend or use the class efficiently .