如何在Java中将分数方程式计算为分数？

import java.math.BigInteger;

class Fraction {
    private BigInteger numerator; // 分子
    private BigInteger denominator; // 分母

    public Fraction(BigInteger numerator, BigInteger denominator) {
        this.numerator = numerator;
        this.denominator = denominator;
        simplify();
    }

    public BigInteger getNumerator() {
        return numerator;
    }

    public BigInteger getDenominator() {
        return denominator;
    }

    private void simplify() {
        BigInteger gcd = numerator.gcd(denominator); // 求最大公约数
        numerator = numerator.divide(gcd);
        denominator = denominator.divide(gcd);
    }

    public Fraction add(Fraction other) {
        BigInteger newNumerator = numerator.multiply(other.getDenominator())
                .add(other.getNumerator().multiply(denominator));
        BigInteger newDenominator = denominator.multiply(other.getDenominator());
        return new Fraction(newNumerator, newDenominator);
    }

    public Fraction subtract(Fraction other) {
        BigInteger newNumerator = numerator.multiply(other.getDenominator())
                .subtract(other.getNumerator().multiply(denominator));
        BigInteger newDenominator = denominator.multiply(other.getDenominator());
        return new Fraction(newNumerator, newDenominator);
    }

    public Fraction multiply(Fraction other) {
        BigInteger newNumerator = numerator.multiply(other.getNumerator());
        BigInteger newDenominator = denominator.multiply(other.getDenominator());
        return new Fraction(newNumerator, newDenominator);
    }

    public Fraction divide(Fraction other) {
        BigInteger newNumerator = numerator.multiply(other.getDenominator());
        BigInteger newDenominator = denominator.multiply(other.getNumerator());
        return new Fraction(newNumerator, newDenominator);
    }

    @Override
    public String toString() {
        return numerator + "/" + denominator;
    }
}

public class Main {
    public static void main(String[] args) {
        Fraction fraction1 = new Fraction(BigInteger.valueOf(3), BigInteger.valueOf(5));
        Fraction fraction2 = new Fraction(BigInteger.valueOf(1), BigInteger.valueOf(2));

        Fraction result = fraction1.add(fraction2);
        System.out.println("Addition: " + result);

        result = fraction1.subtract(fraction2);
        System.out.println("Subtraction: " + result);

        result = fraction1.multiply(fraction2);
        System.out.println("Multiplication: " + result);

        result = fraction1.divide(fraction2);
        System.out.println("Division: " + result);
    }
}