【JAVA 日常练习 13.10】+ comparable接口实现

package Theirteen;

public abstract class Oct {
private String color = "white";
private boolean filled;
private java.util.Date da;
protected Oct(){
da = new java.util.Date();
}
protected Oct(String color,boolean filled){
this.color = color;
this.filled = filled;
}
public String getcolor(){
return this.color;
}
public void setcolor(String color){
this.color = color;
}
public boolean isFilled(){
return this.filled;
}
public void setFilled(boolean filled){
this.filled = filled;
}
public java.util.Date getDate(){
return this.da;
}
public String toString(){
return "created on " + da +"\ncolor : " + color + " and filled : " + filled ;
}
public abstract double getArea();
public abstract double getPerimeter();
}

package Theirteen;

public class Rectangle extends Oct implements Comparable<Rectangle>{

double R;
protected void setR(double R){
this.R = R;
}
public double getArea() {
return Math.PI * R * R ;
}

public double getPerimeter() {
return 0;
}

public Object call() throws Exception {
return null;
}

public int compareTo(Rectangle o) {
if( o.getArea() == this.getArea())
return 1;
else
return 0;
}

}

package Theirteen;

public class Text {

public static void main(String[] args) {
Rectangle a = new Rectangle();
Rectangle b = new Rectangle();
a.setR(7.0);
b.setR(9.0);
System.out.println(a.compareTo(b));
}

}