Java – Encapsulation

Encapsulation:

• The concept of protecting the data with in the class itself.
• We implement Encapsulation through POJO rules
• POJO – Plain Old Java Object

• Implementation rules: (POJO rules)
  • Class is Public (to make the object visible in communication).
  • Variables are Private (other objects cannot access the data directly).
  • Methods are public (to send and receive the data).

Defining get() and set() methods to Balance variable in Account class:

• Set() : takes input value and set to instance variable.
• Get() : returns the value of instance variable.

public class Bank {             private double balance;             public void setBalance(double balance)             {                         this.balance = balance;             }             public double getBalance()             {                         return this.balance;             } }

Employee.java: (POJO class)

public class Employee {             private int num;             private String name;             private double salary;             public void setNum(int num)             {                         this.num = num;             }             public int getNum()             {                         return this.num;             }             public void setName(String name)             {                         this.name = name;             }             public String getName()             {                         return this.name;             }             public void setSalary(double salary)             {                         this.salary = salary;             }             public double getSalary()             {                         return this.salary;             } }

AccessEmployee.java:

class AccessEmployee {             public static void main(String[] args)             {                         Employee e = new Employee();                         e.setNum(101);                         e.setName(“Amar”);                         e.setSalary(35000);                         System.out.println(“Emp Num : “+e.getNum());                         System.out.println(“Emp Name : “+    e.getName());                         System.out.println(“Emp Salary : “+e.getSalary());             } }