创建参数化构造函数以确定随机边长的上限

Question

Im working on a project for class and we have to create a Triangle class that will hold the lengths of each side of the triangle. I created a default constructor that gives each side of the triangle a random length no more than 6. Were asked to create a parameterized constructor that allows the caller to determine the upper bound for the randomized side length, if the supplied upper bound is invalid, this constructor should default to the range used in the default constructor.

Next step is we have to create another parameterized constructor that allows the caller to directly specify the three side length & if any of the three lengths is invalid, all lengths should be randomly generated using the range used in the default constructor.

Im not sure how to get this. This is what i have so far...

import java.util.Random;

public class Triangle {
    int side1;
    int side2;
    int side3;

   //Default Constructor
    public Triangle() {
        Random rng = new Random();
        side1 = rng.nextInt(6)+1;
        side2 = rng.nextInt(6)+1;
        side3 = rng.nextInt(6)+1;
    }

   //toString method
    public String toString() {
        return new String (" " + side1+ " x " +side2+ " x " +side3);
    }

    //Parameterized Constructor
    Triangle (int side11, int side22, int side33) {
        side1 = side11;
        side2 = side22;
        side3 = side33;
    }
}

Answer 1

I'd move the code in the no parameter constructor out to a method that receives that max bound, then use something like the below:

public Triangle() {
    initSides(6);
}

public Triangle(int max) {
    if (max > 0) {
        initSides(max);
    }
    else {
        this(); // call the no parameter constructor
    }
}

public Triangle (int side1, int side2, int side3) {
    if ((side1 > 0) && (side2 > 0) && (side3 > 0)) {
        this.side1 = side1;
        this.side2 = side2;
        this.side3 = side3;
    }
    else {
        this(); // call the no parameter constructor
    }
}

private void initSides(int max) {
    Random rng = new Random();
    side1 = rng.nextInt(max)+1;
    side2 = rng.nextInt(max)+1;
    side3 = rng.nextInt(max)+1;
}

Answer 2

package Proj3;

/**
 * Title: Triangle data class
 * Description: 
 * @author Jahangir Khan N00769290
 * 
 */

import java.util.Random;

public class Triangle {

    int side1;
    int side2;
    int side3;

    public Triangle() {
        initSides(6);
    }


    private void initSides(int max) {
        Random rng = new Random();
        side1 = rng.nextInt(max)+1;
        side2 = rng.nextInt(max)+1;
        side3 = rng.nextInt(max)+1;
    }


    //toString method
    public String toString() {
        return new String (" " + side1+ " x " +side2+ " x " +side3);
    }

    //Parameterized constructor
    public Triangle(int max) {
        this(); 
        if (max > 0) {
            initSides(max);
        }
    }


    //Parameterized constructor
    public Triangle (int side1, int side2, int side3) {
        this(); // call the no parameter constructor
        if ((side1 > 0) && (side2 > 0) && (side3 > 0)) {
            this.side1 = side1;
            this.side2 = side2;
            this.side3 = side3;
        }
    }

    //isEquilateral method
    public boolean isEquilateral() {
        if (side1 == side2 && side1 == side3)
        {
            return true;
        }
        else 
        {
            return false;
        }
    }

    public boolean isRight() {
        int a1 = side1*side1;
        int b1 = side2*side2;
        int c1 = side3*side3;
        if(c1== a1+b1 || b1==a1+c1 || a1==b1+c1){
            return true;
        }
        else {
            return false;
        }

    }

}