DateTools时间插件

package test;

import java.text.DateFormat;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

/**
 * @author ljb
 * @version 1.0 2015-07-10
 */
public class DateTools {
    /**
     * 国际标准
     * 一周是从 周日开始计算
     */
    public static int WEEK_OF_ISO = 0;
    /**
     * 中国标准
     * 一周是重周一开始计算
     */
    public static int WEEK_OF_GBK = 1;
    private int local_GMP = DateTools.WEEK_OF_GBK;

    /**
     * 构造函数默认的每周是从 周一到周日
     */
    public DateTools() {

    }

    /**
     * 构造函数
     *
     * @param GMP 标准类型 WEEK_OF_GBK中国标准 WEEK_OF_ISO国际标准
     */
    public DateTools(int GMP) {
        this.local_GMP = GMP;
    }

    /**
     * 获得当前时间并且以String类型返回。
     *
     * @return 返回的时间格式yyyyMMddHHmmss。
     */
    public String getDate() {
        return getDate("yyyyMMddHHmmss");
    }


    /**
     * 获得当前时间。时间格式根据fmt进行格式化
     *
     * @param fmt 日期格式
     * @return 返回的时间格式根据fmt格式生成
     */
    public String getDate(String fmt) {
        Date myDate = new Date(System.currentTimeMillis());
        SimpleDateFormat sDateformat = new SimpleDateFormat(fmt);
        return sDateformat.format(myDate).toString();
    }


    private Calendar getCal(String strdate, String fmt) {
        Calendar cal = null;
        try {
            if ((strdate != null) && (fmt != null)) {

                SimpleDateFormat nowDate = new SimpleDateFormat(fmt);
                Date d = nowDate.parse(strdate, new ParsePosition(0));
                if (d != null) {
                    cal = Calendar.getInstance();
                    cal.clear();
                    cal.setTime(d);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
        return cal;
    }

    /**
     * 计算 当前日期是本年的第几周
     *
     * @param strdate 计算日期
     * @param fmt     日期格式
     * @return strdate说在年份中有几周，如果strdate的格式为yyyy则默认为当年的1月1日
     */
    public int getWeekOfYear(String strdate, String fmt) {
        int ret = -1;
        try {
            if ((strdate != null) && (fmt != null)) {

                Calendar cal = getCal(strdate, fmt);
                if (cal != null) {

                    ret = cal.get(Calendar.WEEK_OF_YEAR);
                    if (this.local_GMP == DateTools.WEEK_OF_GBK && cal.get(Calendar.DAY_OF_WEEK) == Calendar.SUNDAY) {
                        ret -= 1;
                    }
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ret;
    }

    /**
     * 计算给定日期所在周的全部日期
     *
     * @param strdate 指定日期
     * @param oldfmt  自定日期格式
     * @param newfmt  输出格式
     * @return 结果数组形式输出所在周的日期。指定日期的格式为yyyy或yyyyMM将计算出当年第一周或当月第一周的日期
     */
    public String[] getWeekDay(String strdate, String oldfmt, String newfmt) {
        String[] weekday = new String[7];
        try {
            if ((strdate != null) && (oldfmt != null) && (newfmt != null)) {
                Calendar cal = getCal(strdate, oldfmt);
                if (cal != null) {
                    int dayOfWeek = cal.get(Calendar.DAY_OF_WEEK);
                    dayOfWeek = -dayOfWeek + 1 + this.local_GMP;
                    if (dayOfWeek > 0) {
                        dayOfWeek = -6;
                    }
                    cal.add(Calendar.DATE, dayOfWeek);
                    SimpleDateFormat sdf = new SimpleDateFormat(newfmt);
                    weekday[0] = sdf.format(cal.getTime());
                    for (int i = 1; i < 7; i++) {
                        cal.add(5, 1);
                        weekday[i] = sdf.format(cal.getTime());
                    }
                }
            }
        } catch (IndexOutOfBoundsException iobe) {
            iobe.printStackTrace();
        }
        return weekday;
    }

    /**
     * 计算给定周内的全部日期
     *
     * @param year 年
     * @param week 给定第几周    * @param newfmt    *            返回值格式    * @return 结果数组形式输出所在周的日期。
     */
    public String[] getWeekDate(String year, int week, String newfmt) {
        String[] jweekday = new String[7];
        try {
            if ((year != null) && (year.length() == 4) && (week > 0) && (newfmt != null)) {
                Calendar cal = getCal(year + "0101", "yyyyMMdd");
                if (cal != null) {
                    week--;
                    cal.add(5, week * 7 - cal.get(7) + 2);
                    SimpleDateFormat sdf = new SimpleDateFormat(newfmt);
                    jweekday[0] = sdf.format(cal.getTime());
                    for (int i = 1; i < 7; i++) {
                        cal.add(5, 1);
                        jweekday[i] = sdf.format(cal.getTime());
                    }
                }
            }
        } catch (IndexOutOfBoundsException iobe) {
            iobe.printStackTrace();
        }
        return jweekday;
    }

    /**
     * 计算指定日期是星期几    *    * @param strdate    *            指定日期    * @param oldfmt    *            指定日期格式    * @param fmt    *            输出格式    * @return 返回结果为fmt+结果。
     */
    public String getDayOfWeek(String strdate, String oldfmt, String fmt) {
        String sWeek = null;
        try {
            if ((strdate != null) && (oldfmt != null) && (fmt != null)) {
                Calendar cal = getCal(strdate, oldfmt);
                if (cal != null) {
                    int iWeek = cal.get(7);
                    sWeek = fmt + (iWeek - 1 == 0 ? 7 : iWeek - 1);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return sWeek;
    }

    /**
     * 计算指定年共有多少周    *    * @param year    *            指定年 格式yyyy    * @return 返回周数
     */
    public int getWeekNum(String year) {
        int weeknum = -1;
        try {
            if (year != null) {
                Calendar cal = getCal(year + "1231", "yyyyMMdd");
                if (cal != null) {
                    if (cal.get(3) == 1) cal.add(5, -7);
                    weeknum = cal.get(3);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return weeknum;
    }

    /**
     * 计算两个给定的时间之差    *    * @param startdate    *            开始日期    * @param enddate    *            结束日期    * @param fmt    *            日期格式    * @param refmt    *            返回值格式 ms毫秒 s秒 m分 h小时 d天    * @return 返回值
     */
    public String cntTimeDifference(String startdate, String enddate, String fmt, String refmt) {
        String ret = null;
        try {
            if ((startdate != null) && (enddate != null) && (fmt != null) && (refmt != null)) {
                Date scal = getCal(startdate, fmt).getTime();
                Date ecal = getCal(enddate, fmt).getTime();
                if ((scal == null) || (ecal == null)) {
                    return null;
                } else {
                    long diffMillis = ecal.getTime() - scal.getTime();
                    long diffSecs = diffMillis / 1000L;
                    long diffMins = diffMillis / 60000L;
                    long diffHours = diffMillis / 3600000L;
                    long diffDays = diffMillis / 86400000L;
                    if (refmt.equals("ms")) ret = Long.toString(diffMillis);
                    else if (refmt.equals("s")) ret = Long.toString(diffSecs);
                    else if (refmt.equals("m")) ret = Long.toString(diffMins);
                    else if (refmt.equals("h")) ret = Long.toString(diffHours);
                    else if (refmt.equals("d")) ret = Long.toString(diffDays);
                    else ret = Long.toString(diffHours);
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return ret;
    }

    /**
     * 计算指定日期经过多少分钟后的日期    *    * @param deftime    *            自定日期    * @param oldfmt    *            日期格式    * @param timediff    *            分钟为单位    * @param newfmt    *            返回值的格式    * @return 返回日期，timediff >0向前计算，timediff<0向后计算
     */
    public String getBeforeTime(String deftime, String oldfmt, int timediff, String newfmt) {
        String rq = null;
        try {
            if ((deftime != null) && (!deftime.equals(""))) {
                Calendar cal = getCal(deftime, oldfmt);
                if (cal != null) {
                    cal.add(Calendar.MINUTE, -timediff);
                    SimpleDateFormat sdf = new SimpleDateFormat(newfmt);
                    rq = sdf.format(cal.getTime());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return rq;
    }

    /**
     * 计算指定日期经过多少小时后的日期    *    * @param deftime    *            自定日期    * @param oldfmt    *            日期格式    * @param timediff    *            小时为单位    * @param newfmt    *            返回值的格式    * @return 返回日期，timediff >0向前计算，timediff<0向后计算
     */
    public String getBeforeTimeByH(String deftime, String oldfmt, int timediff, String newfmt) {
        String rq = null;
        try {
            if ((deftime != null) && (!deftime.equals(""))) {
                Calendar cal = getCal(deftime, oldfmt);
                if (cal != null) {
                    cal.add(12, -timediff * 60);
                    SimpleDateFormat sdf = new SimpleDateFormat(newfmt);
                    rq = sdf.format(cal.getTime());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return rq;
    }

    /**
     * 计算指定日期经过多少月后的日期    *    * @param deftime    *            自定日期    * @param oldfmt    *            日期格式    * @param timediff    *            月为单位    * @param newfmt    *            返回值的格式    * @return 返回日期，timediff >0向前计算，timediff<0向后计算
     */
    public String getBeforeTimeByM(String deftime, String oldfmt, int timediff, String newfmt) {
        String rq = null;
        try {
            if ((deftime != null) && (!deftime.equals(""))) {
                Calendar cal = getCal(deftime, oldfmt);
                if (cal != null) {
                    cal.add(2, -timediff);
                    SimpleDateFormat sdf = new SimpleDateFormat(newfmt);
                    rq = sdf.format(cal.getTime());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return rq;
    }

    /**
     * 日期格式化    *    * @param mydate    *            日期    * @param oldfmt    *            旧格式    * @param newfmt    *            新格式    * @return 返回值的格式根据newfmt根式返回
     */
    public String fmtDate(String mydate, String oldfmt, String newfmt) {
        String restr = null;
        try {
            if ((mydate != null) && (oldfmt != null) && (newfmt != null)) {
                SimpleDateFormat newDate = new SimpleDateFormat(newfmt);
                Calendar cal = getCal(mydate, oldfmt);
                if (cal != null) {
                    restr = newDate.format(cal.getTime());
                }
            }
        } catch (Exception e) {
            e.printStackTrace();
        }
        return restr;
    }

    /**
     * 将文字行的date格式成Date类型    * @param mydate    * @param fmt    * @return
     */
    public Date fmtDate(String myDate, String fmt) {
        Date newDate = null;
        if ((myDate != null) && (fmt != null)) {
            Calendar cal = getCal(myDate, fmt);
            newDate = cal.getTime();
        }
        return newDate;
    }

    public String fmtDate(Date myDate, String fmt) {
        String newDate = "";
        SimpleDateFormat sDateformat = new SimpleDateFormat(fmt);
        newDate = sDateformat.format(myDate).toString();
        return newDate;
    }

    public String fmtDate(Long myDate, String fmt) {
        Calendar calendar = Calendar.getInstance();
        calendar.setTimeInMillis(myDate);
        DateFormat formatter = new SimpleDateFormat(fmt);
        return formatter.format(calendar.getTime());
    }   /*public static void main(String[] args){      DateTools dt = new DateTools();      System.out.print(dt.fmtDate(1462878420000l,"yyyy-MM-dd HH:mm:ss"));   }*/

    /**
     * 计算某年某月有多少天     * @param year    * @return
     */
    public int getMonthDays(int year, int month) {
        if (month > 12 || month < 1) {
            throw new RuntimeException("month is error " + month);
        }
        String bigmonth = "1,3,5,7,8,10,12";
        String smallmonth = "4,6,9,11";
        if (bigmonth.indexOf(month + "") > -1) {
            return 31;
        }
        if (smallmonth.indexOf(month + "") > -1) {
            return 30;
        }
        if (year % 400 == 0 || (year % 4 == 0 && year % 100 != 0)) {
            return 29;
        } else {
            return 28;
        }
    }
}