Rectangle

Main.java

/**
 * Created by chengyao on 2017/1/12.
 */
public class Main {
    public static void main(String[] args) {
        Rectangle rect = new Rectangle(1, 3, 2.5, 4);
        System.out.println("长方形的位置：（"+rect.getX()+","+rect.getY()+"),面积为："+rect.getArea());
        rect = new Rectangle(3, 5, 4, 8);
        System.out.println("现在长方形的位置：（"+rect.getX()+","+rect.getY()+"),面积为："+rect.getArea());
    }
}

Rectangle.java

/**
 * Created by chengyao on 2017/1/13.
 */
public class Rectangle {
    private double x;
    private double y;
    private double width;
    private double length;

    public Rectangle(double x, double y, double width, double length) {
        this.x = x;
        this.y = y;
        this.width = width;
        this.length = length;
    }

    public Rectangle() {
        this.x = 0;
        this.y = 0;
        this.width = 0;
        this.length = 0;
    }

    public double getX() {
        return x;
    }

    public double getY() {
        return y;
    }

    public double getWidth() {
        return width;
    }

    public double getLength() {
        return length;
    }

    public double getArea(){
        return width * length;
    }
}