Java课后题——（三角形类）设计一个名为triangle的类来扩展geometricobject类，该类包括

设计一个名为triangle的类来扩展geometricobject类，该类包括

• 三个名为side1,side2,side3的double数据域表示这个三角形的三条边
• 一个无参构造方法创建默认三角形
• 一个能创建带指定size的三角形构造方法
• 所有三个数据域的访问器
• 是否填充
• 面积，周长，颜色 GeometricObject类如下：

  abstract class GeometricObject{
  
  	private boolean filled;
  	private String color;
  	private java.util.Date dateCreated;
  
  	protected GeometricObject() {
  		this(false,"white");
  		dateCreated = new java.util.Date();
  	}
  
  	protected GeometricObject(boolean filled, String color) {
  		//super();
  		this.filled = filled;
  		this.color = color;
  		dateCreated = new java.util.Date();
  	}
  
  	public boolean isFilled() {
  		return filled;
  	}
  
  	public void setFilled(boolean filled) {
  		this.filled = filled;
  	}
  
  	public String getColor() {
  		return color;
  	}
  
  	public void setColor(String color) {
  		this.color = color;
  	}
  
  	public java.util.Date getDateCreated() {
  		return dateCreated;
  	}
  
  	public void setDateCreated(java.util.Date dateCreated) {
  		this.dateCreated = dateCreated;
  	}
  
  	@Override
  	public String toString() {
  		return "created on"+dateCreated+"\ncolor"+color+"and filled:"+filled;
  	}
  
  	public abstract double getArea();
  
  	public abstract double getPerimater();
  }
  

  Triangle类如下：

• public class TriangleFromGeometricObject extends GeometricObject{
  
  	private double side1;
  	private double side2;
  	private double side3;
  	
  	public TriangleFromGeometricObject() {
  		super();
  	}
  	
  	public TriangleFromGeometricObject(boolean filled, String color,double side1,double side2,double side3) {
  		super(filled, color);
  		this.side1 = side1;
  		this.side2 = side2;
  		this.side3 = side3;
  	}
  
  	public double getSide1() {
  		return side1;
  	}
  
  	public void setSide1(double side1) {
  		this.side1 = side1;
  	}
  
  	public double getSide2() {
  		return side2;
  	}
  
  	public void setSide2(double side2) {
  		this.side2 = side2;
  	}
  
  	public double getSide3() {
  		return side3;
  	}
  
  	public void setSide3(double side3) {
  		this.side3 = side3;
  	}
  
  	@Override
  	public double getArea() {
  		double area = Math.sqrt((getPerimater()/2)*(getPerimater()/2-side1)*(getPerimater()/2-side2)*(getPerimater()/2-side3));
  		return area;
  	}
  
  	@Override
  	public double getPerimater() {
  		return side1 + side2 + side3;
  	}
  
  	@Override
  	public String toString() {
  		return "TriangleFromGeometricObject [side1=" + side1 + ", side2=" + side2 + ", side3=" + side3 + ", toString()="
  				+ super.toString() + "]";
  	}
  }

   

• 测试类：

• public class TriangleCombine {
  
  	public static void main(String[] args) {
  		
  		java.util.Scanner input = new java.util.Scanner(System.in);
  		
  		System.out.println("请输入是否填充：");
  		boolean filled = input.nextBoolean();
  		
  		System.out.println("请输入颜色：");
  		String colorFFF = input.nextLine();
  		String color = input.nextLine();
  		
  		System.out.println("请输入三角形的三条边：");
  		double side1 = input.nextDouble();
  		double side2 = input.nextDouble();
  		double side3 = input.nextDouble();
  		
  		GeometricObject triangle = new TriangleFromGeometricObject(filled,color,side1,side2,side3);
  	
  		System.out.println("filled="+triangle.isFilled());
  		System.out.println("color="+triangle.getColor());
  		System.out.println("dateCrated="+triangle.getDateCreated());
  		System.out.println("side1="+side1+"\nside2="+side2+"\nside3="+side3);
  		System.out.println("getArea="+triangle.getArea());
  		System.out.println("getPerimater="+triangle.getPerimater());
  		System.out.println("toString="+triangle.toString());
  	
  	
  	
  	}
  
  }
  

  java初学者，若有不足请大家指出！谢谢！