java写个类，写写注释就更好了

Question

模仿circle类 /1、成员变量，针对类的属性 private int r; //2、成员方法，针对类的行为 public int getR()//get访问器，getter { return r; } public void setR(int a)//set访问器，setter { r = a; } public double getArea() { return Math.PI * r * r; }}

public class CircleTest { public static void main(String[] args) { // TODO Auto-generated method stub Circle c = new Circle(); c.setR(3); System.out.println("半径为" + c.getR() + "的圆的面积是" + c.getArea()); }}

写出矩形类、三角形类。随机生成100个长度和宽度范围在[1, 100]的矩形，然后对这些矩形排序。Rectangle[] a = new Rectangle[100];示例结果：第1大的矩形为：98 * 96 = ……第2大的矩形为：97 * 96 = ……第100大的矩形为：3 * 4 = 12

Answer 1

1、矩形类：

package cn.personal.demo06;

public class Rectangle {

    // 定义成员变量，宽和高
    private int width;
    private int heigh;

    // 添加有参构造方法
    public Rectangle(int width, int heigh) {
        super();
        this.width = width;
        this.heigh = heigh;
    }

    // 添加get/set方法
    public int getWidth() {
        return width;
    }

    public void setWidth(int width) {
        this.width = width;
    }

    public int getHeigh() {
        return heigh;
    }

    public void setHeigh(int heigh) {
        this.heigh = heigh;
    }

    //获取面积的方法
    public int getArea(int wi,int he) {
        return wi*he;
    }
}

2、矩形测试类

package cn.personal.demo06;

import java.util.Arrays;

public class RectangleTest {

    public static void main(String[] args) {

        // 定义Rectangle数组，长度为100；
        Rectangle[] rects = new Rectangle[100];
        
        // 定义Rectangle中的width数组，长度为100；
        int[] widths = new int[100];
        
        // 定义Rectangle中的height数组，长度为100；
        int[] heights = new int[100];
        
        for (int i = 0; i < rects.length; i++) {
            int wr=getRandon();
            int hr=getRandon();
            rects[i]=new Rectangle(wr, hr);
            widths[i] = rects[i].getWidth();
            heights[i] = rects[i].getHeigh();
        }

        //将宽度和高度进行升序排序
        Arrays.sort(widths);
        Arrays.sort(heights);
        
        //循环输出打印
        for (int i = 1; i <= rects.length; i++) {
            System.out.println("第"+i+"大的矩形为："
                    +widths[rects.length-i]+"*"+heights[rects.length-i]+"="
                    +rects[rects.length-i].getArea(widths[rects.length-i],heights[rects.length-i]));
        }
    }

    public static int getRandon() {
        return (int) (Math.random() * 99 + 1);
    }
}

3、矩形测试效果

1、三角形类

package cn.personal.demo06;

public class Triangle {
    
    //定义成员变量，三条边
    private int line1;
    private int line2;
    private int line3;

    //添加有参构造
    public Triangle(int line1, int line2, int line3) {
        super();
        this.line1 = line1;
        this.line2 = line2;
        this.line3 = line3;
    }
    
    //添加get/set方法
    public int getLine1() {
        return line1;
    }

    public void setLine1(int line1) {
        this.line1 = line1;
    }

    public int getLine2() {
        return line2;
    }

    public void setLine2(int line2) {
        this.line2 = line2;
    }

    public int getLine3() {
        return line3;
    }

    public void setLine3(int line3) {
        this.line3 = line3;
    }

    //添加求面积方法
    public double getArea() {
        double p = (line1 + line2 + line3) / 2d;
        return Math.sqrt(p * (p - line1) * (p - line2) * (p - line3));
    }

}

2、三角形测试类

package cn.personal.demo06;

public class TriangleTest {

    public static void main(String[] args) {

        Triangle triangle = new Triangle(3, 4, 5);
        System.out.println("三边长为" + triangle.getLine1() + ","
                + triangle.getLine2() + "," + triangle.getLine3() + "的三角形面积:"
                + triangle.getArea());
        triangle = new Triangle(6, 7, 8);
        System.out.println("三边长为" + triangle.getLine1() + ","
                + triangle.getLine2() + "," + triangle.getLine3() + "的三角形面积:"
                + triangle.getArea());
    }

}

3、三角形测试效果