пятая лаба Java

//Complex.java

package com.company;

import java.util.ArrayList;

public class Complex {


    public Complex()
    {

    }

    public  Complex(Complex val)
    {
        this.real = val.real;
        this.imaginary = val.imaginary;
    }

    public  Complex(double real , double imaginary)
    {
        this.real = real;
        this.imaginary = imaginary;
    }

    public  Complex sum(Complex right)
    {
        this.real+=right.real;
        this.imaginary+= right.imaginary;

        return this;
    }

    public  static  Complex sum(Complex left, Complex right)
    {
        Complex res = new Complex(left);

       return   res.sum(right);
    }

    public  Complex multiply(Complex right)
    {
        this.real = this.real*right.real - this.imaginary*right.imaginary;
        this.imaginary = this.imaginary * right.real + this.real * right.imaginary;

        return this;
    }

    public  static  Complex multiply(Complex left, Complex right)
    {
     Complex res = new Complex(left);

     return res.multiply(right);
    }

    public Complex division(Complex right)
    {
        if (right.magnitude() == 0) throw  new IllegalArgumentException("Division by zero!");
        this.real = (this.real *right.real + this.imaginary * right.imaginary)/(right.real * right.real + right.imaginary*right.imaginary);
        this.imaginary = (this.imaginary * right.real + this.real * right.imaginary)/(right.real * right.real + right.imaginary*right.imaginary);

        return this;
    }

    public  static Complex division (Complex left, Complex right)
    {
        Complex res = new Complex(left);

        return res.division(right);
    }

    private Complex pow(double degree)
    {

        this.real = this.real == 0 ? 0 : Math.pow(this.magnitude(),degree) * Math.cos(degree * this.phase());
        this.imaginary = this.imaginary == 0 ? 0 : Math.pow(this.magnitude(),degree) * Math.sin(degree * this.phase());

        return this;
    }

    public  static  Complex pow(Complex val, double degree)
    {
        return val.pow(degree);
    }

    private ArrayList<Complex>  sqrt(int n)
    {
        ArrayList<Complex> res = new ArrayList<>();

        for (int i = 0; i< n;++i)
        {
            double real = Math.sqrt(this.phase()) * Math.cos((this.phase() + 2 * i * Math.PI)/n);
            double imaginary = Math.sqrt(this.phase()) * Math.sin((this.phase() + 2 * i * Math.PI)/n);

            res.add(new Complex(real,imaginary));
        }

        return res;

    }

    public  static ArrayList<Complex> sqrt(Complex val, int n)
    {
        return val.sqrt(n);
    }

    public  double magnitude()
    {
        if (real > 0)
            return Math.sqrt(real*real+imaginary*imaginary);
        if (real < 0 && imaginary >= 0)  return Math.PI + Math.sqrt(real*real+imaginary*imaginary);
        if ( real < 0 && imaginary < 0) return  -Math.PI + Math.sqrt(real*real+imaginary*imaginary);
        if(real == 0 && imaginary >0) return Math.PI/2;
        if(real == 0 && imaginary <0) return -Math.PI/2;
        return 0;
    }

    public double phase()
    {
        return Math.atan2(imaginary,real);
    }

    @Override
    public String toString() {
        final StringBuffer sb = new StringBuffer("Complex{");
        sb.append("real=").append(real);
        sb.append(", imaginary=").append(imaginary);
        sb.append('}');
        return sb.toString();
    }

    private double real = 0;
    private  double imaginary = 0;
}
//Main.java

package com.company;

import java.util.InputMismatchException;
import java.util.Scanner;

public class Main {

    public static void main(String[] args) {

        double re = 0;
        double im = 0;

        Scanner in = new Scanner(System.in);

        try
        {
            System.out.print("Please enter a real part of the firts complex naumber:");
            re = in.nextDouble();
            System.out.print("Please enter a imaginary part of the firts complex naumber:");
            im = in.nextDouble();
        }
        catch (InputMismatchException ex)
        {
            System.err.println("Error, you should enter a number");
            System.exit(1);
        }

        Complex ob1 = new Complex(re, im);

        try
        {
            System.out.print("Please enter a real part of the second complex number:");
            re = in.nextDouble();
            System.out.print("Please enter a imaginary part of the second complex number:");
            im = in.nextDouble();
        }
        catch (InputMismatchException ex)
        {
            System.err.println("Error, you should enter a number");
            System.exit(2);
        }

        Complex ob2 = new Complex(re, im);

        System.out.println(ob1 + " + " + ob2 + " = " + Complex.sum(ob1, ob2));
        System.out.println(ob1 + " * " + ob2 + " = " + Complex.multiply(ob1, ob2));
        try
        {
            System.out.println(ob1 + " / " + ob2 + " = " + Complex.division(ob1, ob2));
        }
        catch (IllegalArgumentException ex)
        {
            System.err.println(ex.getMessage());
            System.exit(3);
        }

        System.out.println(ob1 + " ^ " + 3 + " = " + Complex.pow(ob1,3));
        System.out.println("sqrt(" + ob1 + ") = " +Complex.sqrt(ob1,3));
    }
}