Сортировка массива объектов по дате

this.calendar = Calendar.getInstance();
this.calendar.set(dateYear, dateMouth, dateDay);

    public Calendar getCalendar() {
        return calendar;
    }

import java.text.SimpleDateFormat;
 
class MyClass implements Comparable<MyClass> { 
    private String name;
    private double price;
    private double discount;
    private Calendar date;
    
    public MyClass(String name, double price, double discount, Calendar date) {
        this.name = name;
        this.price = price;
        this.discount = discount;
        this.date = date;
    }
        
    @Override
    public int compareTo(MyClass that) {
        int dtCompare = this.date.compareTo(that.date);
        if (dtCompare != 0) 
            return dtCompare;
        
        int nameCompare = this.name.compareTo(that.name);
        if (nameCompare != 0) 
            return nameCompare;
        
        int priceCompare = Double.compare(this.price, that.price);
        if (priceCompare != 0) 
            return priceCompare;
        
        return Double.compare(this.discount, that.discount);
    }
    
    @Override
    public String toString() {
        return name + ", " + price + ", " + discount + ", " + 
               new SimpleDateFormat("dd.MM.yyyy").format(date.getTime());
    }
}
 
class Tester {
    public static void main(String[] args) {
        Calendar dt1 = Calendar.getInstance();
        dt1.set(2013, Calendar.JUNE, 8);
 
        Calendar dt2 = Calendar.getInstance();
        dt2.set(2013, Calendar.JUNE, 1);
 
        MyClass a = new MyClass("a", 100., 0., dt1);
        MyClass b = new MyClass("b", 100., 0., dt2);   
        MyClass[] arr = new MyClass[2];
        
        arr[0] = a;
        arr[1] = b;
        
        Arrays.sort(arr);
        System.out.println(arr[0]);
        System.out.println(arr[1]);
    }
}

@Override
    public int compareTo(Object object) {

class MyClass implements Comparable<MyClass> { 
    private String name;
    private double price;
    private double discount;
    private Calendar date;
    
    public String getName() {
        return name;
    }
    
    public double getPrice() {
        return price;
    }
    
    public double getDiscount() {
        return discount;
    }
    
    public Calendar getDate() {
        return date;
    }
    
    public MyClass(String name, double price, double discount, Calendar date) {
        this.name = name;
        this.price = price;
        this.discount = discount;
        this.date = date;
    }
        
    @Override
    public int compareTo(MyClass that) {
        int dtCompare = this.date.compareTo(that.date);
        if (dtCompare != 0) 
            return dtCompare;
        
        int nameCompare = this.name.compareTo(that.name);
        if (nameCompare != 0) 
            return nameCompare;
        
        int priceCompare = Double.compare(this.price, that.price);
        if (priceCompare != 0) 
            return priceCompare;
        
        return Double.compare(this.discount, that.discount);
    }
    
    @Override
    public String toString() {
        return name + ", " + price + ", " + discount + ", " + 
               new SimpleDateFormat("dd.MM.yyyy").format(date.getTime());
    }
}
 
class Tester {
    public static void main(String[] args) {
        Calendar dt1 = Calendar.getInstance();
        dt1.set(2013, Calendar.JUNE, 8);
 
        Calendar dt2 = Calendar.getInstance();
        dt2.set(2013, Calendar.JUNE, 1);
 
        MyClass a = new MyClass("a", 100., 0., dt1);
        MyClass b = new MyClass("b", 200., 0., dt2);   
        MyClass c = new MyClass("c", 50., 0., dt2);   
        MyClass[] arr = new MyClass[3];
        
               
        arr[0] = a;
        arr[1] = b;
        arr[2] = c;
        
        MyClassComparator comparator = new MyClassComparator();
        comparator.setCompareMethod(MyClassCompareMethods.BY_NAME);
        
        Arrays.sort(arr, comparator);
        System.out.println("Compare by Name:");
        System.out.println(arr[0]);
        System.out.println(arr[1]);
        System.out.println(arr[2]);
        
        comparator.setCompareMethod(MyClassCompareMethods.BY_DATE);
        
        Arrays.sort(arr, comparator);
        System.out.println("Compare by Date:");
        System.out.println(arr[0]);
        System.out.println(arr[1]);
        System.out.println(arr[2]);
        
        
        comparator.setCompareMethod(MyClassCompareMethods.BY_PRICE);
        
        Arrays.sort(arr, comparator);
        System.out.println("Compare by Price:");
        System.out.println(arr[0]);
        System.out.println(arr[1]);
        System.out.println(arr[2]);
    }
}
 
enum MyClassCompareMethods {
    BY_NAME,
    BY_PRICE,
    BY_DISCOUNT,
    BY_DATE;
}
 
class MyClassComparator implements Comparator<MyClass> {
    private MyClassCompareMethods compareMethod;
    
    public void setCompareMethod(MyClassCompareMethods method) {
        compareMethod = method;
    }
    
    @Override
    public int compare(MyClass o1, MyClass o2) {
        switch (compareMethod) {
            case BY_NAME:
                int nameDiff = o1.getName().compareTo(o2.getName());
                if (nameDiff != 0) 
                    return nameDiff;
                break;
            case BY_PRICE: 
                int priceDiff = Double.compare(o1.getPrice(), o2.getPrice());
                if (priceDiff != 0) 
                    return priceDiff;
                break;
            case BY_DISCOUNT:
                int discountDiff = Double.compare(
                        o1.getDiscount(), o2.getDiscount());
                if (discountDiff != 0) 
                    return discountDiff;
            case BY_DATE:
                int dateDiff = o1.getDate().compareTo(o2.getDate());
        }
        //Если приоритетное сравнение вернуло 0 - сравниваем по умолчанию
        return o1.compareTo(o2);
    }    
}

int priceCompare = Double.compare(this.price, that.price);
        if (priceCompare != 0) 
            return priceCompare;

double d = 2147483650d;
int i = (int)d;
System.out.println("d="+d);
System.out.println("i="+i);

/**
 * @author mutagen
 */
public class WrongComparation {
 
    /**
     * @param args the command line arguments
     */
    public static void main(String[] args) {
        int trueAccumulator = 0;
        int falseAccumulator = 0;
        for (int i = 0; i < Integer.MAX_VALUE; i++) {
            int c = (compare(i, i)) ? trueAccumulator++ : falseAccumulator++;
        }
        System.out.println("false " + falseAccumulator);
        System.out.println("true " + trueAccumulator);
    }
 
    static boolean compare(double a, double b) {
        return (Double.compare(a, b) == 0); 
    }
}