Understanding Encapsulation in Java

Encapsulation is one of the four pillars of OOPs. It means wrapping data (fields) and the methods that operate on that data into a single unit — a class — while restricting direct access to the internal state.

How to Achieve Encapsulation

• Declare class fields as private
• Provide public getter and setter methods to read and update the fields
• Add validation logic inside setters to control what values are allowed

Example

class Employee {
    private String name;
    private double salary;

    public String getName() {
        return name;
    }
    public void setName(String name) {
        this.name = name;
    }
    public double getSalary() {
        return salary;
    }
    public void setSalary(double salary) {
        if (salary > 0) {
            this.salary = salary;
        }
    }
}

Benefits of Encapsulation

• Protects object state from unauthorized or invalid modification
• Hides implementation details, exposing only what's necessary through a clean interface
• Makes code easier to maintain, since internal changes don't affect external code
• Improves security by controlling how fields are accessed and updated