原型

//Prototype
class Shape implements Cloneable  {
    public int lineCount;

    public Shape(int lineCount) {
        this.lineCount = lineCount;
    }

    public Shape clone() {
        try {
            return (Shape) super.clone();
        }
        catch (CloneNotSupportedException e) { 
            return null; 
        }
    }
}

//ConcretePrototype
class Square extends Shape {
    public Square() {
        super(4);
    }
}

//Client
class ShapeMaker {  
    private Shape shape;

    public ShapeMaker(Shape shape) {
        this.shape = shape;
    }

    public Shape makeShape() {
        return shape.clone();
    }
}

var square = new Square();
var maker = new ShapeMaker(square);

var square1 = maker.makeShape();
var square2 = (Square)maker.makeShape();

System.out.println("lineCount1 is " + 
    square1.lineCount);
System.out.println("lineCount2 is " + 
    square2.lineCount);