java 三角形类 Triangle的用法详解

// 创建的类
package java_testquestions;
class GeometricObject{
 private String color = "white";
 private boolean filled;
 private java.util.Date dateCreated; 
 public GeometricObject() {
 dateCreated = new java.util.Date();
 }
 public GeometricObject(String color,boolean filled) {
 dateCreated = new java.util.Date();
 this.color = color;
 this.filled = filled;
 }
 public String getColor() {
 return color;
 }
 public void setColor(String color) {
 this.color = color;
 }
 public boolean filled() {
 return filled;
 }
 public void setFilled(boolean filled) {
 this.filled = filled;
 }
 public java.util.Date getDateCreated(){
 return dateCreated;
 }
 public String toString() {
 return "created on "+dateCreated +"\n color: "+color + " and filled: "+filled;
 }
}
public class Triangle extends GeometricObject
{
 private double side1;
 private double side2;
 private double side3;
 String color;
 
 Triangle(){
 side1 = 1.0;
 side2 = 1.0;
 side3 = 1.0;
 }
 public Triangle(double side1,double side2,double side3) {
 this.side1 = side1;
 this.side2 = side2;
 this.side3 = side3;
 }
 public double getSide1() {
 return side1;
 }
 public double getSide2() {
 return side2;
 }
 public double getSide3() {
 return side3;
 }
// 父类中已有该方法
 public void setColor(String Color) {
 color = Color;
 }
 public String getColor() {
 return color;
 }
 public double getArea() {
 double s = (side1+side2+side3)*1.0/2;
 double area = Math.sqrt(s*(s-side1)*(s-side2)*(s-side3));
 return area;
 }
 
 public double getPerimeter() {
 return side1+side2+side3;
 }
 public String toString() {
 return "Triangle: side1 = "+side1 +"side2 = "+side2 +" side3 = "+side3;
 }
}

// 测试类
package java_testquestions;
import java.util.Scanner;
public class Triangle_Test 
{
 public static void main(String[] args)
 {
 Scanner input = new Scanner(System.in);
 
 System.out.println("请输入三角形的三条边："); // 需要用字符串类型输入，这样在下面 输入颜色时就不会报错
 String side11 = input.nextLine();
 double side1 = Double.parseDouble(side11);
 String side22 = input.nextLine();
 double side2 = Double.parseDouble(side22);
 String side33 = input.nextLine();
 double side3 = Double.parseDouble(side33);
// double side1 = input.nextDouble();
// double side2 = input.nextDouble();
// double side3 = input.nextDouble();
 Triangle triangle = new Triangle(side1,side2,side3);
 
 System.out.println("请输入三角形的颜色: ");
 String color = input.nextLine();
 triangle.setColor(color);
 System.out.println("\n");
 
 System.out.println("请输入是否填充 true or false：");
 boolean filled = input.nextBoolean();
 triangle.setFilled(filled);
 
 System.out.println("三角形的面积为 ："+triangle.getArea());
 System.out.println("三角形的周长为 ："+triangle.getPerimeter());
 System.out.println("三角形的颜色为 ："+triangle.getColor());
 System.out.println("三角形是否填充 ："+triangle.filled());
 }
}

 String side11 = input.nextLine();
 double side1 = Double.parseDouble(side11);
 String side22 = input.nextLine();
 double side2 = Double.parseDouble(side22);
 String side33 = input.nextLine();
 double side3 = Double.parseDouble(side33);

public static void main(String[] args) {
// TODO 自动生成的方法存根
int a,b,c;
System.out.println(“请输入三角形的三边”);
@SuppressWarnings(“resource”)
Scanner sc=new Scanner(System.in);
System.out.println(“a=”);
a=sc.nextInt();
System.out.println(“b=”);
b=sc.nextInt();
System.out.println(“c=”);
c=sc.nextInt();
if((a+b)>c&&(b+c)>a&&(c+a)>b)
System.out.println(a+”,”+b+”,”+c+”能构成三角形！”);
else
System.out.println(a+”,”+b+”,”+c+”不能构成三角形！”);
}