Employee.java

class Employee {
  private String name;
  private String position;

  public Employee(String name, String position) {
    this.name = name;
    this.position = position;
  }

  public Employee changeName(String name) {
    return new Employee(name, this.position);
  }

  public Employee changePosition(String position) {
    return new Employee(this.name, position);
  }
}

SalaryCalculator.java

class SalaryCalculator {
  private Employee employee;

  public SalaryCalculator(Employee emp) {
    this.employee = emp;
  }

  public int calculateSalary() {
    if (employee.getPosition().matches("Senior(.*)")) {
      return 10000;
    } else {
      return 5000;
    }
  }
}

SalaryProgram.java

class SalaryProgram {
  // Calling function
  public static void main(String[] args) {
    Employee jane = new Employee('Jane', 'Senior Programmer');
  
    // Injected dependency jane in SalaryCalculator constructor
    SalaryCalculator calculator = new SalaryCalculator(jane);
    calculator.calculateSalary(); // Return 10000
  
    // IMPORTANT: This does not change the employee private variable of calculator.
    jane = new Employee('Other Jane', 'Junior Programmer');
  
    // Encapsulation is not broken
    calculator.calculateSalary(); // Still returns 10000
  }
}