Java工具类DateUtils实例详解

import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;/** * 描述:公共日期工具类 */public class DateUtils {  public static String DATE_FORMAT = "yyyy-MM-dd";  public static String DATE_TIME_FORMAT = "yyyy-MM-dd HH:mm:ss";  public static String DATE_FORMAT_CHINESE = "yyyy年M月d日";  /**   * 获取当前日期   *    *    * @return   *    */  public static String getCurrentDate() {    String datestr = null;    SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT);    datestr = df.format(new Date());    return datestr;  }  /**   * 获取当前日期时间   *    *    * @return   *    */  public static String getCurrentDateTime() {    String datestr = null;    SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_TIME_FORMAT);    datestr = df.format(new Date());    return datestr;  }  /**   * 获取当前日期时间   *    *    * @return   *    */  public static String getCurrentDateTime(String Dateformat) {    String datestr = null;    SimpleDateFormat df = new SimpleDateFormat(Dateformat);    datestr = df.format(new Date());    return datestr;  }  public static String dateToDateTime(Date date) {    String datestr = null;    SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_TIME_FORMAT);    datestr = df.format(date);    return datestr;  }  /**   * 将字符串日期转换为日期格式   *    *    * @param datestr   * @return   *    */  public static Date stringToDate(String datestr) {      if(datestr ==null ||datestr.equals("")){        return null;      }    Date date = new Date();    SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT);    try {      date = df.parse(datestr);    } catch (ParseException e) {      date=DateUtils.stringToDate(datestr,"yyyyMMdd");    }    return date;  }  /**   * 将字符串日期转换为日期格式   * 自定義格式   *    * @param datestr   * @return   *    */  public static Date stringToDate(String datestr, String dateformat) {    Date date = new Date();    SimpleDateFormat df = new SimpleDateFormat(dateformat);    try {      date = df.parse(datestr);    } catch (ParseException e) {      e.printStackTrace();    }    return date;  }  /**   * 将日期格式日期转换为字符串格式   *    *    * @param date   * @return   *    */  public static String dateToString(Date date) {    String datestr = null;    SimpleDateFormat df = new SimpleDateFormat(DateUtils.DATE_FORMAT);    datestr = df.format(date);    return datestr;  }  /**   * 将日期格式日期转换为字符串格式 自定義格式   *    * @param date   * @param dateformat   * @return   */  public static String dateToString(Date date, String dateformat) {    String datestr = null;    SimpleDateFormat df = new SimpleDateFormat(dateformat);    datestr = df.format(date);    return datestr;  }  /**   * 获取日期的DAY值   *    *    * @param date   *      输入日期   * @return   *    */  public static int getDayOfDate(Date date) {    int d = 0;    Calendar cd = Calendar.getInstance();    cd.setTime(date);    d = cd.get(Calendar.DAY_OF_MONTH);    return d;  }  /**   * 获取日期的MONTH值   *    *    * @param date   *      输入日期   * @return   *    */  public static int getMonthOfDate(Date date) {    int m = 0;    Calendar cd = Calendar.getInstance();    cd.setTime(date);    m = cd.get(Calendar.MONTH) + 1;    return m;  }  /**   * 获取日期的YEAR值   *    *    * @param date   *      输入日期   * @return   *    */  public static int getYearOfDate(Date date) {    int y = 0;    Calendar cd = Calendar.getInstance();    cd.setTime(date);    y = cd.get(Calendar.YEAR);    return y;  }  /**   * 获取星期几   *    *    * @param date   *      输入日期   * @return   *    */  public static int getWeekOfDate(Date date) {    int wd = 0;    Calendar cd = Calendar.getInstance();    cd.setTime(date);    wd = cd.get(Calendar.DAY_OF_WEEK) - 1;    return wd;  }  /**   * 获取输入日期的当月第一天   *    *    * @param date   *      输入日期   * @return   *    */  public static Date getFirstDayOfMonth(Date date) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    cd.set(Calendar.DAY_OF_MONTH, 1);    return cd.getTime();  }  /**   * 获得输入日期的当月最后一天   *    * @param date   */  public static Date getLastDayOfMonth(Date date) {    return DateUtils.addDay(DateUtils.getFirstDayOfMonth(DateUtils.addMonth(date, 1)), -1);  }  /**   * 判断是否是闰年   *    *    * @param date   *      输入日期   * @return 是true 否false   *    */  public static boolean isLeapYEAR(Date date) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    int year = cd.get(Calendar.YEAR);    if (year % 4 == 0 && year % 100 != 0 | year % 400 == 0) {      return true;    } else {      return false;    }  }  /**   * 根据整型数表示的年月日，生成日期类型格式   *    * @param year   *      年   * @param month   *      月   * @param day   *      日   * @return   *    */  public static Date getDateByYMD(int year, int month, int day) {    Calendar cd = Calendar.getInstance();    cd.set(year, month-1, day);    return cd.getTime();  }  /**   * 获取年周期对应日   *    * @param date   *      输入日期   * @param iyear   *      年数  負數表示之前   * @return   *    */  public static Date getYearCycleOfDate(Date date, int iyear) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    cd.add(Calendar.YEAR, iyear);    return cd.getTime();  }  /**   * 获取月周期对应日   *    * @param date   *      输入日期   * @param i   * @return   *    */  public static Date getMonthCycleOfDate(Date date, int i) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    cd.add(Calendar.MONTH, i);    return cd.getTime();  }  /**   * 计算 fromDate 到 toDate 相差多少年   *    * @param fromDate   * @param toDate   * @return 年数   *    */  public static int getYearByMinusDate(Date fromDate, Date toDate) {    Calendar df=Calendar.getInstance();    df.setTime(fromDate);    Calendar dt=Calendar.getInstance();    dt.setTime(toDate);    return dt.get(Calendar.YEAR)-df.get(Calendar.YEAR);  }  /**   * 计算 fromDate 到 toDate 相差多少个月   *    * @param fromDate   * @param toDate   * @return 月数   *    */  public static int getMonthByMinusDate(Date fromDate, Date toDate) {    Calendar df=Calendar.getInstance();    df.setTime(fromDate);    Calendar dt=Calendar.getInstance();    dt.setTime(toDate);    return dt.get(Calendar.YEAR)*12+dt.get(Calendar.MONTH)-        (df.get(Calendar.YEAR)*12+df.get(Calendar.MONTH));  }  /**   * 计算 fromDate 到 toDate 相差多少天   *    * @param fromDate   * @param toDate   * @return 天数   *    */  public static long getDayByMinusDate(Object fromDate, Object toDate) {    Date f=DateUtils.chgObject(fromDate);    Date t=DateUtils.chgObject(toDate);    long fd=f.getTime();    long td=t.getTime();    return (td-fd)/(24L * 60L * 60L * 1000L);  }  /**   * 计算年龄   *    * @param birthday   *      生日日期   * @param calcDate   *      要计算的日期点   * @return   *    */  public static int calcAge(Date birthday, Date calcDate) {    int cYear=DateUtils.getYearOfDate(calcDate);    int cMonth=DateUtils.getMonthOfDate(calcDate);    int cDay=DateUtils.getDayOfDate(calcDate);       int bYear=DateUtils.getYearOfDate(birthday);    int bMonth=DateUtils.getMonthOfDate(birthday);    int bDay=DateUtils.getDayOfDate(birthday);    if(cMonth>bMonth||(cMonth==bMonth&&cDay>bDay)){      return cYear-bYear;    }else{      return cYear-1-bYear;    }  }  /**   * 从身份证中获取出生日期   *    * @param idno   *      身份证号码   * @return   *    */  public static String getBirthDayFromIDCard(String idno) {    Calendar cd = Calendar.getInstance();    if (idno.length() == 15) {      cd.set(Calendar.YEAR, Integer.valueOf("19" + idno.substring(6, 8))          .intValue());      cd.set(Calendar.MONTH, Integer.valueOf(idno.substring(8, 10))          .intValue() - 1);      cd.set(Calendar.DAY_OF_MONTH,          Integer.valueOf(idno.substring(10, 12)).intValue());    } else if (idno.length() == 18) {      cd.set(Calendar.YEAR, Integer.valueOf(idno.substring(6, 10))          .intValue());      cd.set(Calendar.MONTH, Integer.valueOf(idno.substring(10, 12))          .intValue() - 1);      cd.set(Calendar.DAY_OF_MONTH,          Integer.valueOf(idno.substring(12, 14)).intValue());    }    return DateUtils.dateToString(cd.getTime());  }  /**   * 在输入日期上增加（+）或减去（-）天数   *    * @param date   *      输入日期   * @param imonth   *      要增加或减少的天数   */  public static Date addDay(Date date, int iday) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    cd.add(Calendar.DAY_OF_MONTH, iday);    return cd.getTime();  }  /**   * 在输入日期上增加（+）或减去（-）月份   *    * @param date   *      输入日期   * @param imonth   *      要增加或减少的月分数   */  public static Date addMonth(Date date, int imonth) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    cd.add(Calendar.MONTH, imonth);    return cd.getTime();  }  /**   * 在输入日期上增加（+）或减去（-）年份   *    * @param date   *      输入日期   * @param imonth   *      要增加或减少的年数   */  public static Date addYear(Date date, int iyear) {    Calendar cd = Calendar.getInstance();    cd.setTime(date);    cd.add(Calendar.YEAR, iyear);    return cd.getTime();  }  /**   * 將OBJECT類型轉換為Date   * @param date   * @return   */  public static Date chgObject(Object date){    if(date!=null&&date instanceof Date){      return (Date)date;    }    if(date!=null&&date instanceof String){      return DateUtils.stringToDate((String)date);    }    return null;  }  public static long getAgeByBirthday(String date){    Date birthday = stringToDate(date, "yyyy-MM-dd");    long sec = new Date().getTime() - birthday.getTime();    long age = sec/(1000*60*60*24)/365;    return age;  }  /**   * @param args   */  public static void main(String[] args) {    //String temp = DateUtil.dateToString(getLastDayOfMonth(new Date()),    ///   DateUtil.DATE_FORMAT_CHINESE);    //String s=DateUtil.dateToString(DateUtil.addDay(DateUtil.addYear(new Date(),1),-1));    long s=DateUtils.getDayByMinusDate("2012-01-01", "2012-12-31");    System.err.println(s);  }}