当具体对象采用不同的构造函数参数时，在Java中为工厂

您有两种选择：

1）抽象工厂：

RectangularShape extends Shape

RoundShape extends Shape

并

RectangularShapeFactory

RoundShapeFactory

2）构建器（另请参见有效Java中的第2项）

public Shape {    private final int x;    private final int y;    private final double radius;    private Shape(Builder builder) {        x = builder.x;        y = builder.y;        radius = builder.radius;    }    public static class Builder {        private final int x;        private final int y;        private double radius;        public Builder(int x, int y) { this.x = x; this.y = y;        }        public Builder radius(double radius) { this.radius = radius; return this;        }        public Shape build() { return new Shape(this);        }        }}//in client pre    Shape rectangle = new Shape.Builder(x,y).build();    Shape circle = new Shape.Builder(x,y).radius(radiusValue).build();