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x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x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  当硎局
   * @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,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();
  }

  /**
   * OBJECT型DQDate
   * @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);


  }

}