How to call Rational class in Driver class

and use an arraylist to find the max and sort in acceding order?

public class Rational implements Comparable { // Data fields for numerator and denominator private long numerator = 0; private long denominator = 1;

/** Construct a rational with default properties */ public Rational() { this(0, 1); }

/** Construct a rational with specified numerator and denominator */ public Rational(long numerator, long denominator) { long gcd = gcd(numerator, denominator); this.numerator = ((denominator > 0) ? 1 : -1) * numerator / gcd; this.denominator = Math.abs(denominator) / gcd; }

/** Find GCD of two numbers */ private static long gcd(long n, long d) { long n1 = Math.abs(n); long n2 = Math.abs(d); int gcd = 1; for (int k = 1; k <= n1 && k <= n2; k++) { if (n1 % k == 0 && n2 % k == 0) gcd = k; }

return gcd; }

/** Return numerator */ public long getNumerator() { return numerator; } /** Set numerator */ public void setNumerator(long n) { numerator = n; }

/** Return denominator */ public long getDenominator() { return denominator; } /** Set denominator */ public void setDenominator(long d) { denominator = d; }

/** Add a rational number to this rational */ public Rational add(Rational secondRational) { long n = numerator * secondRational.getDenominator() + denominator * secondRational.getNumerator(); long d = denominator * secondRational.getDenominator(); return new Rational(n, d); }

/** Subtract a rational number from this rational */ public Rational subtract(Rational secondRational) { long n = numerator * secondRational.getDenominator() - denominator * secondRational.getNumerator(); long d = denominator * secondRational.getDenominator(); return new Rational(n, d); }

/** Multiply a rational number to this rational */ public Rational multiply(Rational secondRational) { long n = numerator * secondRational.getNumerator(); long d = denominator * secondRational.getDenominator(); return new Rational(n, d); }

/** Divide a rational number from this rational */ public Rational divide(Rational secondRational) { long n = numerator * secondRational.getDenominator(); long d = denominator * secondRational.numerator; return new Rational(n, d); }

@Override public String toString() { if (denominator == 1) return numerator + ""; else return numerator + "/" + denominator; }

@Override // Override the equals method in the Object class public boolean equals(Object other) { if ((this.subtract((Rational)(other))).getNumerator() == 0) return true; else return false; }

@Override // Implement the compareTo method in Comparable public int compareTo(Rational o) { if (this.subtract(o).getNumerator() > 0) return 1; else if (this.subtract(o).getNumerator() < 0) return -1; else return 0; } }