对于当前月份和日期但年份不同的日期，经过的月份计算未给出正确的结果

我正在尝试计算自特定日期以来经过的月份，该函数工作正常，尽管如果我将今天的日期与过去的不同年份放在一起，它会给我一个月的差异（不到一个月）。

假设对于所有日期，该函数都运行良好，除了：

如果今天是“2014-03-06”（YYYY、MM、DD），并且我将日期处理为“2006-03-06”，则结果会短一个月，但是如果我明天使用相同的日期，结果就好了。想知道我哪里出错了。下面是代码：

public static int months(String d) {

        SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd");
        Date d1 = null;
        try {
            d1 = f.parse(d);
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        //   Date d2 = (getCurrentDate());
        Date d2 = getCurrentDate(); 
        Calendar c1 = Calendar.getInstance();
        c1.setTime(d1);
        Calendar c2 = Calendar.getInstance();
        c2.setTime(d2);
        int diff = 0;
        if (c2.after(c1)) {
            while (c2.after(c1)) {
                c1.add(Calendar.MONTH, 1);
                if (c2.after(c1)) {
                    diff++;
                }
            }
        } else if (c2.before(c1)) {
            while (c2.before(c1)) {
                c1.add(Calendar.MONTH, -1);
                if (c1.before(c2)) {
                    diff--;
                }
            }
        }
        System.out.println(diff);
        return diff;
    }

结果：95 个月。

理想情况下应该是 96 个月。

请不要考虑函数的静态性质，我已将此代码隔离在不同的项目中以进行测试。

这是 c1 和 c2 的值：

java.util.GregorianCalendar[time=1141583400000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Asia/Kolkata",offset=19800000,dstSavings=0,useDaylight=false,transitions=6,lastRule=null],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2006,MONTH=2,WEEK_OF_YEAR=10,WEEK_OF_MONTH=2,DAY_OF_MONTH=6,DAY_OF_YEAR=65,DAY_OF_WEEK=2,DAY_OF_WEEK_IN_MONTH=1,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=0,MILLISECOND=0,ZONE_OFFSET=19800000,DST_OFFSET=0] and c2 is: java.util.GregorianCalendar[time=1394044200000,areFieldsSet=true,areAllFieldsSet=true,lenient=true,zone=sun.util.calendar.ZoneInfo[id="Asia/Kolkata",offset=19800000,dstSavings=0,useDaylight=false,transitions=6,lastRule=null],firstDayOfWeek=1,minimalDaysInFirstWeek=1,ERA=1,YEAR=2014,MONTH=2,WEEK_OF_YEAR=10,WEEK_OF_MONTH=2,DAY_OF_MONTH=6,DAY_OF_YEAR=65,DAY_OF_WEEK=5,DAY_OF_WEEK_IN_MONTH=1,AM_PM=0,HOUR=0,HOUR_OF_DAY=0,MINUTE=0,SECOND=0,MILLISECOND=0,ZONE_OFFSET=19800000,DST_OFFSET=0]
95

我的缺点是 getCurrentDate()：

public static Date getCurrentDate() {
        String DateStr = new SimpleDateFormat("yyyy-MM-dd"/*,
                current*/).format(Calendar.getInstance().getTime());
        //  String DateStr = formattedDate;
        Date date = null;
        try {
            date = new SimpleDateFormat("yyyy-MM-dd"/*, current*/).parse(DateStr);
        } catch (ParseException e) {
            e.printStackTrace();
        }
        java.sql.Date dx = new java.sql.Date(date.getTime());
        return dx;
    }

的比较Calendar after and before还包括时间信息，这可能会将计算抛到最后，导致比较失败......

尝试将值调整为日期边界...例如...

import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class TestMonths {

    public static final String TEST1 = "2006-03-06";
    public static final String TEST2 = "2014-03-06";

    public static void main(String[] args) {
        System.out.println(months(TEST2));
    }

    public static Date getCurrentDate() throws ParseException {

        return new SimpleDateFormat("yyyy-MM-dd").parse(TEST1);

    }

    public static int months(String d) {

        SimpleDateFormat f = new SimpleDateFormat("yyyy-MM-dd");
        Date d1 = null;
        Date d2 = null;
        try {
            d1 = f.parse(d);
            d2 = (getCurrentDate());
        } catch (ParseException e) {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
        Calendar c1 = Calendar.getInstance();
        c1.setTime(d1);
        Calendar c2 = Calendar.getInstance();
        c2.setTime(d2);
        int diff = 0;
        if (c2.after(c1)) {
            System.out.println("After");
            setStartOfDay(c1);
            setEndOfDay(c2);
            while (c2.after(c1)) {
                c1.add(Calendar.MONTH, 1);
                if (c2.after(c1)) {
                    diff++;
                }
            }
        } else if (c2.before(c1)) {
            System.out.println("Before");
            setStartOfDay(c2);
            setEndOfDay(c1);
            while (c2.before(c1)) {
                c1.add(Calendar.MONTH, -1);
                if (c2.before(c1)) {
                    diff--;
                }
            }
        }
        System.out.println(diff);
        return diff;
    }

    public static void setStartOfDay(Calendar cal) {
        cal.set(Calendar.HOUR_OF_DAY, 0);
        cal.set(Calendar.MINUTE, 0);
        cal.set(Calendar.SECOND, 0);
        cal.set(Calendar.MILLISECOND, 0);
    }

    public static void setEndOfDay(Calendar cal) {
        cal.set(Calendar.HOUR_OF_DAY, 23);
        cal.set(Calendar.MINUTE, 59);
        cal.set(Calendar.SECOND, 59);
        cal.set(Calendar.MILLISECOND, 99);
    }
}

ps-我还更正了“之前”分支（其中c2是“之前”c1）因为存在逻辑错误......