Replace Type Code with Subclass

TODO

 

 

before

public class ReplaceTypeCodeWithSubclasses_before {
	static class Employee {
	    //...
	    
	    static final int ENGINEER = 0;
	    static final int SALESMAN = 1;
	    static final int MANAGER = 2;
	    
	    private int type;
	    
	    public Employee (int arg) { type = arg; }
	    
	    public int monthlySalary;
	    public int commission;
	    public int bonus;
	    public int payAmount() {
	        switch (type) {
	            case ENGINEER : return monthlySalary;
	            case SALESMAN : return monthlySalary + commission;
	            case MANAGER : return monthlySalary + bonus;
	            default : throw new RuntimeException("Incorrect Code");
	        }
	    }
	    public void initializeBasicSalary(int monthlySalary, int commission, int bonus) {
	    	this.monthlySalary = monthlySalary;
	    	this.commission = commission;
	    	this.bonus = bonus;
	    }
	}
	
	public static void main(String[] args) {
		Employee employee = new Employee(Employee.ENGINEER);
		employee.initializeBasicSalary(450, 80, 100);

		System.out.println("pays : " + employee.payAmount());
	}

}

 

 

after

abstract int getType();
static Employee create(int type) {
switch (type) {
case ENGINEER:
return new Engineer();
case SALESMAN:
return new Salesman();
case MANAGER:
return new Manager();
default:
throw new IllegalArgumentException("Incorrect type code value");
}
}

https://eunjin3786.tistory.com/405