geometricobject.java

java程序设计导论（daniel liang著） 所有偶数课后习题答案

// GeometricObject.java: The abstract GeometricObject class
public abstract class GeometricObject {
  private String color = "white";
  private boolean filled;

  /**Default construct*/
  protected GeometricObject() {
  }

  /**Construct a geometric object*/
  protected GeometricObject(String color, boolean filled) {
    this.color = color;
    this.filled = filled;
  }

  /**Getter method for color*/
  public String getColor() {
    return color;
  }

  /**Setter method for color*/
  public void setColor(String color) {
    this.color = color;
  }

  /**Getter method for filled. Since filled is boolean,
     so, the get method name is isFilled*/
  public boolean isFilled() {
    return filled;
  }

  /**Setter method for filled*/
  public void setFilled(boolean filled) {
    this.filled = filled;
  }

  /**Abstract method findArea*/
  public abstract double findArea();

  /**Abstract method findPerimeter*/
  public abstract double findPerimeter();
}