设计模式之生成实例_Prototype复制模式_通过复制生成实例

前言

​​博主github​​

​​博主个人博客http://blog.healerjean.com​​

1、业务场景

**当创建对象的代价比较大的时候，采用这种模式, **

实现方式、 容器,clone

2、实例代码1

2.1、被复制的抽象对象

@Data
@ToString
public abstract class Shape implements Cloneable {

    public  String id;
    public  String type;

    abstract void draw();

    @Override
    public Object clone() {
        Object clone = null;
        try {
            clone = super.clone();
        } catch (CloneNotSupportedException e) {
            e.printStackTrace();
        }
        return clone;
    }
}

2.2、子类

2.2.1、​​Rectangle​​ extends Shape

@Data
@ToString
public class Rectangle extends Shape {

    private String pectangleName ;

    public Rectangle(){
        type = "Rectangle";
    }

    @Override
    public void draw() {
        System.out.println(id+":"+type+":"+pectangleName);
    }
}

2.2.2、​​Square​​ extends Shape

@Data
@ToString
public class Square extends Shape {

    private String squareName ;

    public Square(){
        type = "Square";
    }

    @Override
    public void draw() {
        System.out.println(id+":"+type+":"+squareName);
    }
}

2.3、创建和复制的类​​ShapeCache​​

public class ShapeCache {

    private static Map<String, Shape> shapeMap   = new HashMap<>();

    /**
     * 通过map和拷贝 获取全新对象
     */
    public static Shape getByType(String shapeId) {
        Shape cachedShape = shapeMap.get(shapeId);
        return (Shape) cachedShape.clone();
    }

    /**
     * 创建原型
     */
    public static void create(Shape shape) {
        shapeMap.put(shape.getType(),shape);
    }
}

2.4、测试

public class Main {

        public static void main(String[] args) {

            Rectangle rectangle = new Rectangle();
            rectangle.setType("rectangle");
            rectangle.setId("1");
            rectangle.setPectangleName("rectangleName");
            ShapeCache.create(rectangle);
            Square square = new Square();
            square.setType("square");
            square.setId("2");
            square.setSquareName("squareName");
            ShapeCache.create(square);

            rectangle = (Rectangle)ShapeCache.getByType("rectangle") ;
            rectangle.draw();
            square =    (Square)ShapeCache.getByType("square") ;
            square.draw();

        }
    
    
            // 1:rectangle:rectangleName
            // 2:square:squareName
}

3、总结：

​​ShapeCache​​用于创建和克隆 clone 复制实例对象