BankStructure.java

package Solutions;

import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;

/*Client uses the component class interface to interact with objects in the composition structure. If recipient is the leaf then request will be handled 
directly. If recipient is a composite, then it usually forwards the request to its child for performing the additional operations.
*/

interface Employee {
	public int getId();

	public String getName();

	public double getSalary();

	public void print();

	public void add(Employee employee);

	public void remove(Employee employee);

	public Employee getChild(int i);
}

class BankManager implements Employee {
	private int id;
	private String name;
	private double salary;

	public BankManager(int id, String name, double salary) {
		this.id = id;
		this.name = name;
		this.salary = salary;
	}

	List<Employee> employees = new ArrayList<Employee>();

	@Override
	public void add(Employee employee) {
		employees.add(employee);
	}

	@Override
	public Employee getChild(int i) {
		return employees.get(i);
	}

	@Override
	public void remove(Employee employee) {
		employees.remove(employee);
	}

	@Override
	public int getId() {
		return id;
	}

	@Override
	public String getName() {
		return name;
	}

	@Override
	public double getSalary() {
		return salary;
	}

	@Override
	public void print() {
		System.out.println("==========================");
		System.out.println("Id =" + getId());
		System.out.println("Name =" + getName());
		System.out.println("Salary =" + getSalary());
		System.out.println("==========================");

		Iterator<Employee> it = employees.iterator();

		while (it.hasNext()) {
			Employee employee = it.next();
			employee.print();
		}
	}
}

class Cashier implements Employee {

	private int id;
	private String name;
	private double salary;

	public Cashier(int id, String name, double salary) {
		this.id = id;
		this.name = name;
		this.salary = salary;
	}

	@Override
	public void add(Employee employee) {
		// this is leaf node so this method is not applicable to this class.
	}

	@Override
	public Employee getChild(int i) {
		// this is leaf node so this method is not applicable to this class.
		return null;
	}

	@Override
	public int getId() {
		// TODO Auto-generated method stub
		return id;
	}

	@Override
	public String getName() {
		return name;
	}

	@Override
	public double getSalary() {
		return salary;
	}

	@Override
	public void print() {
		System.out.println("==========================");
		System.out.println("Id =" + getId());
		System.out.println("Name =" + getName());
		System.out.println("Salary =" + getSalary());
		System.out.println("==========================");
	}

	@Override
	public void remove(Employee employee) {
		// this is leaf node so this method is not applicable to this class.
	}
}

class Accountant implements Employee {
	/*
	 * In this class,there are many methods which are not applicable to cashier
	 * because it is a leaf node.
	 */
	private int id;
	private String name;
	private double salary;

	public Accountant(int id, String name, double salary) {
		this.id = id;
		this.name = name;
		this.salary = salary;
	}

	@Override
	public void add(Employee employee) {
		// this is leaf node so this method is not applicable to this class.
	}

	@Override
	public Employee getChild(int i) {
		// this is leaf node so this method is not applicable to this class.
		return null;
	}

	@Override
	public int getId() {
		// TODO Auto-generated method stub
		return id;
	}

	@Override
	public String getName() {
		return name;
	}

	@Override
	public double getSalary() {
		return salary;
	}

	@Override
	public void print() {
		System.out.println("=========================");
		System.out.println("Id =" + getId());
		System.out.println("Name =" + getName());
		System.out.println("Salary =" + getSalary());
		System.out.println("=========================");
	}

	@Override
	public void remove(Employee employee) {
		// this is leaf node so this method is not applicable to this class.
	}
}

public class BankStructure {

	public static void main(String[] args) {
		Employee emp1 = new Cashier(101, "Sohan Kumar", 20000.0);
		Employee emp2 = new Cashier(102, "Mohan Kumar", 25000.0);
		Employee emp3 = new Accountant(103, "Seema Mahiwal", 30000.0);
		Employee manager1 = new BankManager(100, "Ashwani Rajput", 100000.0);

		manager1.add(emp1);
		manager1.add(emp2);
		manager1.add(emp3);
		manager1.print();

	}

}