Im modeling a car odometer, by making an odometer class, where when the user makes a new odometer(n), n is the number of counters shown. for instance an odometer(6) would be 000000 and the be incremented through the driver program.

My problem is when i get down to the compareTo method, i cant figure out how to compare the parameter object o to an odometer object to determine whether their mileage is less than equal to or greater than the one being compared. My teacher created a driver program to test our classes, and I have everything else working except comparing the objects. any advice would be great.

this is the driver

and this is my classpublic class OdometerDriver { public static void main(String [] args) { Odometer od6 = new Odometer(), od4 = new Odometer(4); System.out.println("od6 #1: " + od6); System.out.println("od4 #1: " + od4); for (int i = 1; i <= 21993; i++) { od6.inc(); od4.inc(); } System.out.println("od6 #2: " + od6); System.out.println("od4 #2: " + od4); System.out.println("od6 rollovers: " + od6.rollovers()); System.out.println("od4 rollovers: " + od4.rollovers()); System.out.println("od4 total mileage: " + od4.totalMileage()); System.out.println("od4 = od6? " + od4.equals(od6)); System.out.println("od4.compareTo(od6): "+ od4.compareTo(od6)); od4.inc(); System.out.println("od4 #3: " + od4); System.out.println("od4.compareTo(od6): "+ od4.compareTo(od6)); } }

import java.text.*; public class Odometer implements Comparable{ int n; int miles, totalMiles; int rolls; public Odometer(){ this.n = 6; } public Odometer(int n){ this.n = n; if(n < 3 || n > 6){ System.out.println("N is outside the range. Must be 3 - 6."); n = 6; } miles = 0; rolls = 0; totalMiles = 0; } public void inc(){ miles++; if(n == 3){ if(miles > 999){ miles = 0; rolls++; }totalMiles = (miles + (rolls * 1000)); } if(n == 4){ if(miles > 9999){ miles = 0; rolls++; }totalMiles = (miles + (rolls * 10000)); } if(n == 5){ if(miles > 99999){ miles = 0; rolls++; }totalMiles = (miles + (rolls * 100000)); } if(n == 6){ if(miles > 999999){ miles = 0; rolls++; }totalMiles = (miles + (rolls * 1000000)); } } public int currentMileage(){ return miles; } public int totalMileage(){ return totalMiles; } public int rollovers(){ return rolls; } public String toString(){ String value = ""; DecimalFormat df1 = new DecimalFormat("000"); DecimalFormat df2 = new DecimalFormat("0000"); DecimalFormat df3 = new DecimalFormat("00000"); DecimalFormat df4 = new DecimalFormat("000000"); if(n == 3) value = "" + df1.format(miles); else if(n == 4) value = "" + df2.format(miles) + ""; else if(n == 5) value = "" + df3.format(miles); else if(n == 6) value = "" + df4.format(miles); return value; } public int compareTo(Object o){ o = (Odometer)o; if( == ) return 0; else if( > ) return 1; else return -1; // Returns a -1, 0, or 1 as this object is less than, equal to, or // greater than the specified object (the formal argument). Comparison // made on total mileage. } public boolean equals(Object odometer){ if( == ) return true; else return false; // returns true if the total mileage of 2 // odometers are equal (i.e. including rollovers), // false otherwise. Note that odometers of different // lengths can be equal, i.e. have the same // total mileage } public boolean hasRolledOver(){ if(rolls >= 1) return true; else return false; } }