[JAVA] 상속 클래스 생성 과정

하위 클래스를 생성하면 상위 클래스가 먼저 생성됨

 

package ch03;

public class Customer {
	protected int customerID; //하위 클래스에선 접근 가능하지만 외부 클래스는 접근 불가
	protected String customerName;
	protected String customerGrade;
	int bonusPoint; //package default ->다른 package에서 접근 불가
	double bonusRatio;
	
	/*public Customer() {
		
		customerGrade="SILVER";
		bonusRatio=0.01;
		
		System.out.println("Customer() call");
	}*/
	public Customer(int customerID, String customerName) {
		this.customerID=customerID;
		this.customerName=customerName;
		
		customerGrade="SILVER";
		bonusRatio=0.01;
		System.out.println("Customer(int,String) call");
	}
	public int clacPrice(int price) {
		bonusPoint+=price*bonusRatio;
		return price;
	}
	public String showCustomerInfo() {
		return customerName+"님의 등급은 "+customerGrade+"이며 보너스포인트는 " + bonusPoint+"입니다.";
	}
	public int getCustomerID() {
		return customerID;
	}
	public void setCustomerID(int customerID) {
		this.customerID = customerID;
	}
	public String getCustomerName() {
		return customerName;
	}
	public void setCustomerName(String customerName) {
		this.customerName = customerName;
	}
	public String getCustomerGrade() {
		return customerGrade;
	}
	public void setCustomerGrade(String customerGrade) {
		this.customerGrade = customerGrade;
	}
	

}

package ch03;

public class VIPCustomer extends Customer {
	
	double salesRatio;
	String agentID;
	
	/*public VIPCustomer() {
		// super(); 오류 발생
		super(0,null); //상위 클래스의 생성자를 명시적으로 호출해줘야 O
		bonusRatio=0.05;
		salesRatio=0.1;
		customerGrade="VIP";
		System.out.println("VIP Customer() call");
	}*/
	
	public VIPCustomer(int customerID, String customerName) {
		super(customerID,customerName);
		
		//여기서 값 덮어씌우기!
		customerGrade="VIP";
		bonusRatio=0.1;
		System.out.println("VIP Customer(int,String) call");
		
	}
}

package ch03;

public class CustomerTest {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Customer customerLee= new Customer(10010,"이순신");
		customerLee.bonusPoint=1000;
		System.out.println(customerLee.showCustomerInfo());
		
		VIPCustomer customerKim = new VIPCustomer(10020,"김유신");
		customerKim.bonusPoint=10000;
		System.out.println(customerKim.showCustomerInfo());
	}

}