ex2.java

讲述各种各样的java初始编程 了解编程

/*
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package chenchao2;


import java.util.Random;

/**
 *
 * @author qjxy
 */
public class Ex2 {

    public static void main(String[] args) {
        Ex2 test = new Ex2();
        test.doTest();
    }

    private void doTest() {
        Random r = new Random();
        Point a = new Point(r.nextInt(10), r.nextInt(20));
        Point b = new Point(r.nextInt(10), r.nextInt(20));
        Point c = new Point(r.nextInt(10), r.nextInt(20));
        TriAngle t = new TriAngle(a, b, c);
        System.out.println(t);
    }
}

class TriAngle {

    private Point a;
    private Point b;
    private Point c;
    private double area;
    private double longth;
    private double ab;
    private double bc;
    private double ac;

    public Point getA() {
        return a;
    }

    public void setA(Point a) {

        this.a = a;
    }

    public double getArea() {
        double p = this.getLongth()/2;
        //use the Helen eqution to compute the area of a Triangle
        //假设有一个三角形，边长分别为a、b、c，三角形的面积S可由以下公式求得： 
        //S=√[p(p-a)(p-b)(p-c)] 
        //而公式里的p为半周长： 
        //p=(a+b+c)/2 

        area = Math.sqrt(p* (p-ab)* (p-ac)* (p-bc));
        return area;
    }

    public Point getB() {
        return b;
    }

    public void setB(Point b) {
        this.b = b;
    }

    public Point getC() {
        return c;
    }

    public void setC(Point c) {
        this.c = c;
    }

    public double getLongth() {
        longth = ab + ac + bc;
        return longth;
    }

    public TriAngle(Point a, Point b, Point c) {
        this.a = a;
        this.b = b;
        this.c = c;

        this.ab = this.getAb();
        this.ac = this.getAc();
        this.bc = this.getBc();

        this.area = this.getArea();
        this.longth = this.getLongth();
    }

    private double getDistance(Point s, Point d) {
        double distance = 0;
        distance = Math.sqrt(Math.pow(s.getX() - d.getX(), 2) + Math.pow(s.getY() - d.getY(), 2));
        return distance;
    }

    public double getAb() {
        ab = getDistance(a, b);
        return ab;
    }

    public double getAc() {
        ac = getDistance(a, c);
        return ac;
    }

    public double getBc() {
        bc = getDistance(b, c);
        return bc;
    }

    @Override
    public String toString() {
        String stra = a.toString();
        String strb = b.toString();
        String strc = c.toString();

        String str = "Point A is:\t" + stra + '\n' + 
                     "Point B is:\t" + strb + '\n' + 
                     "Point C is:\t" + strc + '\n' +
                     "Side AB is:\t" + this.getAb() + '\n' +
                     "Side AC is:\t" + this.getAc() + '\n' +
                     "Side BC is:\t" + this.getBc() + '\n';
        str = str + "The Area is :\t " + this.getArea() + '\n';
        str = str + "The Longth is :\t " + this.getLongth() + '\n';
        return str;
    }
}

class Point {

    private int x;
    private int y;

    public int getX() {
        return x;
    }

    public void setX(int x) {
        this.x = x;
    }

    public int getY() {
        return y;
    }

    public void setY(int y) {
        this.y = y;
    }

    public Point(int x, int y) {
        this.x = x;
        this.y = y;
    }

    @Override
    public String toString() {
        String str = "[the x is :\t" + this.x + '\t' + "the y is :\t" + this.y + ']';
        return str;
    }
}