介紹

之前沒用過這個模式，目前的理解是相似的物件就不用一直 new，感覺很方便

原型模式實作

1. 跟前幾篇一樣先建立會員類別

public class Member {
    private String name;
    private String age;
    
    ...        
}

2. 這個會員多一個電腦類別

public class Computer {
    private String brand;
}

3. 電腦類別增加 Clone 相關程式

public class Computer implements Cloneable {
    private String brand;

    @NonNull
    @Override
    protected Object clone() throws CloneNotSupportedException {
        return super.clone();
    }

    public String getBrand() {
        return brand;
    }

    public void setBrand(String brand) {
        this.brand = brand;
    }
}

4. 會員類別內增加電腦類別

public class Member {
    private String name;
    private String age;
    private Computer computer;
    
    ...        
}

5. 會員類別內增加複製方法和電腦類別建構子

public class Member implements Cloneable {
    
    ...
        
    @NonNull
    @Override
    public Member clone() throws CloneNotSupportedException{
        Member clone = new Member(this.computer);
        clone.setName(this.name);
        clone.setAge(this.age);
        return clone;
    }
    
    public Member(Computer computer) throws CloneNotSupportedException {
        this.computer = (Computer) computer.clone();
    }    
}

原型模式測試

1. 建立基本會員，電腦品牌為刀碩

Member memberBase = new Member();
memberBase.setName("AndyAWD");
memberBase.setAge("30");

Computer computer = new Computer();
computer.setBrand("ASUS");
memberBase.setComputer(computer);

2. 複製基本會員，新會員 1 重新設定電腦品牌為 APPLE

Member member1 = memberBase.clone();

Computer computer1 = new Computer();
computer1.setBrand("APPLE");
member1.setComputer(computer1);

3. 複製基本會員，新會員 2 重新設定電腦品牌為 MSI

Member member2 = member.clone();

Computer computer2 = new Computer();
computer2.setBrand("MSI");
member2.setComputer(computer2);

4. 輸出結果

基本角色 - 姓名:AndyAWD / 年齡:30 / 電腦品牌:ASUS
會員1 - 姓名:AndyAWD / 年齡:30 / 電腦品牌:APPLE
會員2 - 姓名:AndyAWD / 年齡:30 / 電腦品牌:MSI