cylinder2.java

来自「java课件」· Java 代码 · 共 34 行

public class Cylinder2 extends Circle {
  private double length;
  
  //无参构造方法
  public Cylinder2(){
    super();  //调用父类无参构造方法, 此句可以省略
    length = 1.0;
  }
  
  //使用2个参数构造Cylinder
  public Cylinder2(double radius, double length){
    super(radius);
    this.length = length;
  }
  /** Return length */
  public double getLength() {
    return length;
  }
  
  /** Set length */
  public void setLength(double length) {
    this.length = length;
  }
  
  //覆盖父类的findArea()方法
  public double findArea(){
    return 2 * super.findArea() +
            2 * getRadius() * Math.PI * length;
  }
  /** Return the volume of this cylinder */
  public double findVolume() {
    return super.findArea() * length;
  }
}