使用java基本语法实现的小程序(从1000年1月1日到9999年12月31日所有的对称日)

前面一篇博文虽然写的也对，但是逻辑有点问题，逻辑不是很清楚，所以又写了一份，更改了下逻辑，做一点小记。

 public class CopyOfCompare
{
    public static void main(String[] args)
    {
        CopyOfCompare cm = new CopyOfCompare();
        int i;//年份
        int j = 0;//月份
        int k;//日
        String date = null;//日期
        //年份
        for (i = 1000; i < 9999; i++)
        {
            //判断是否是闰年
            if (i % 4 == 0 && i % 100 != 0 && i % 400 == 0)//闰年
            {
                for (j = 1; j < 13; j++)
                {
                    switch (j)
                    {
                        case 1:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("01") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("01") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 2:
                            for (k = 1; k < 30; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("02") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("02") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 3:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("03") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("03") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 4:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("04") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("04") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 5:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("05") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("05") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 6:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("06") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("06") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 7:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("07") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("07") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 8:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("08") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("08") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 9:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("09") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("09") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 10:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("10") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("10") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 11:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("11") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("11") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 12:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("12") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("12") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                    }
                }
            }
            else
            {
                for (j = 1; j < 13; j++)
                {
                    switch (j)
                    {
                        case 1:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("01") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("01") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 2:
                            for (k = 1; k < 29; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("02") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("02") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 3:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("03") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("03") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 4:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("04") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("04") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 5:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("05") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("05") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 6:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("06") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("06") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 7:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("07") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("07") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 8:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("08") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("08") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 9:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("09") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("09") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 10:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("10") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("10") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 11:
                            for (k = 1; k < 31; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("11") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("11") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                        case 12:
                            for (k = 1; k < 32; k++)
                            {
                                if (k < 10)
                                {
                                    date = String.valueOf(i) + String.valueOf("12") + String.valueOf("0" + k);
                                    cm.change(date);
                                }
                                else
                                {
                                    date = String.valueOf(i) + String.valueOf("12") + String.valueOf(k);
                                    cm.change(date);
                                }
                            }
                            break;
                    }
                }
            }
        }
    }
   
    protected void change(String date)
    {
        String change = date.substring(4, 8);
        change = new StringBuffer(change).reverse().toString();
        if (change.equals(date.substring(0, 4).toString()))
        {
            System.out.println(date.substring(0, 4) + "年" + date.substring(4, 6) + "月" + date.substring(6, 8) + "日");
        }
    }
}