java开发中时间按工具类

package cn.hnedu.util;

import java.io.*;
import java.text.*;
import java.util.*;
import java.sql.Timestamp;
import java.text.DateFormat;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;

public class DateUtils {
  public DateUtils() {
  }

  public final static Calendar myc = Calendar.getInstance();

  public static final int SECOND = 1000;
  public static final int MINUTE = SECOND * 60;
  public static final int HOUR = MINUTE * 60;
  public static final int DAY = HOUR * 24;
  public static final int WEEK = DAY * 7;
  public static final int YEAR = DAY * 365; // or 366 ???

  public static final long GMT_VIETNAM_TIME_OFFSET = HOUR * 8;

  private static long SERVER_TIME_OFFSET = HOUR * 0;

  private static DateFormat ddMMyyyyFormat = new SimpleDateFormat("dd/MM/yyyy");
  private static DateFormat yyyymmddhhmmssFormat = new SimpleDateFormat(
      "yyyy年MM月dd日 kk:mm:ss");
  private static DateFormat mmddhhmmFormat = new SimpleDateFormat(
      "MM月dd日 kk:mm");
  private static DateFormat yyyymmddhhmmFormat = new SimpleDateFormat(
      "yyyy年MM月dd日 kk:mm");
  private static DateFormat dateFormat = SimpleDateFormat.getDateInstance(
      SimpleDateFormat.DEFAULT);
  private static DateFormat datetimeFormat = SimpleDateFormat.
      getDateTimeInstance(SimpleDateFormat.DEFAULT, SimpleDateFormat.DEFAULT);

  /**
   * @return 返回当前时间，返回格式：2003-4-25 14:50:7
   */
  public static String getTime() {
    return getTime("yyyy-MM-dd HH:mm:ss");
  }

  public static Date getDate(String parrten) {
    if (!StringUtils.hasText(parrten)) {
      parrten = "yyyyMMddHH";
    }
    String starttime = DateUtils.getTime(parrten);
    return DateUtils.getStrToDate(starttime, parrten);
  }
 
  public static Date getDate(){
   return getDate("yyyy-MM-dd HH:mm:ss");
  }

  /**
   * 获得当前时间
   * @param parrten 输出的时间格式
   * @return 返回时间
   */
  public static String getTime(String parrten) {
    String timestr;
    if (parrten == null || parrten.equals("")) {
      parrten = "yyyyMMddHHmmss";
    }
    java.text.SimpleDateFormat sdf = new SimpleDateFormat(parrten);
    java.util.Date cday = new Date();
    timestr = sdf.format(cday);
    return timestr;
  }

  /**
   * 时间格式转换
   * @param cday
   * @param parrten
   * @return
   */
  public static String getTime(Date cday, String parrten) {
    String timestr;
    if (parrten == null || parrten.equals("")) {
      parrten = "yyyyMMddHHmmss";
    }
    java.text.SimpleDateFormat sdf = new SimpleDateFormat(parrten);
    timestr = sdf.format(cday);
    return timestr;
  }

  /**
   * 得到昨天的时间
   * @return
   */
  public static String getYestday() {
    String timestr;
    java.util.Calendar cc = myc;
    cc.roll(cc.DAY_OF_YEAR, -1);
    java.text.SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
    timestr = sdf.format(cc.getTime());
    return timestr;
  }

  //将一个时间字符串转换为date型
  public static Date getStrToDate(String time, String parrten) {
    SimpleDateFormat formatter = new SimpleDateFormat(parrten);
    ParsePosition pos = new ParsePosition(0);
    Date dt1 = formatter.parse(time, pos);
    return dt1;
  }

  /**
   * 将时间转换为xxxx年xx月xx日格式
   * @param t1 原时间
   * @param parrten 原时间格式
   * @return
   */
  public static String getTime(String t1, String parrten) {
    SimpleDateFormat formatter = new SimpleDateFormat(parrten);
    SimpleDateFormat formatter2 = new SimpleDateFormat("yyyy年MM月dd日");
    ParsePosition pos = new ParsePosition(0);
    Date dt1 = formatter.parse(t1, pos);
    return formatter2.format(dt1);
  }

  /**
   * 将时间转换为parrten2格式
   * @param t1
   * @param parrten
   * @param parrten2
   * @return
   */
  public static String getTime(String t1, String parrten, String parrten2) {
    SimpleDateFormat formatter = new SimpleDateFormat(parrten);
    SimpleDateFormat formatter2 = new SimpleDateFormat(parrten2);
    ParsePosition pos = new ParsePosition(0);
    Date dt1 = formatter.parse(t1, pos);
    return formatter2.format(dt1);
  }

  /**
   * 比较两个字符串时间的大小
   * @param t1 时间1
   * @param t2 时间2
   * @param parrten 时间格式 :yyyy-MM-dd
   * @return 返回long =0相等，>0 t1>t2，<0 t1<t2
   */
  public static long compareStringTime(String t1, String t2, String parrten) {
    SimpleDateFormat formatter = new SimpleDateFormat(parrten);
    ParsePosition pos = new ParsePosition(0);
    ParsePosition pos1 = new ParsePosition(0);
    Date dt1 = formatter.parse(t1, pos);
    Date dt2 = formatter.parse(t2, pos1);
    long l = dt1.getTime() - dt2.getTime();
    return l;
  }

  //相差的天数
  public static int compareTime(String time1, String time2) {
    long l = compareStringTime(time1, time2, "yyyy-MM-dd");
    long days = l / 1000 / 60 / 60 / 24;
    return (int) days;
  }

  public static synchronized String getDateDDMMYYYY(Date date) {
    return ddMMyyyyFormat.format(date);
  }

  public static synchronized String getDateindex(Date date) {
    return yyyymmddhhmmssFormat.format(date);
  }

  public static synchronized String getDateSearch(Date date) {
    return mmddhhmmFormat.format(date);
  }

  public static synchronized String getDateNoSencond(Date date) {
    return yyyymmddhhmmFormat.format(date);
  }

  public static synchronized String formatDate(Date date) {
    return dateFormat.format(date);
  }

  public static synchronized String formatDateTime(Date date) {
    return datetimeFormat.format(date);
  }

  public static Timestamp getCurrentGMTTimestamp() {
    return new Timestamp(System.currentTimeMillis() - SERVER_TIME_OFFSET);
  }

  public static void updateCurrentGMTTimestamp(Timestamp timeToUpdate) {
    timeToUpdate.setTime(System.currentTimeMillis() - SERVER_TIME_OFFSET);
  }

  public static Date getVietnamDateFromGMTDate(Date date) {
    return new Date(date.getTime() + GMT_VIETNAM_TIME_OFFSET);
  }

  public static Date convertGMTDate(Date gmtDate, int hourOffset) {
    return new Date(gmtDate.getTime() + hourOffset * HOUR);
  }

  public static Timestamp convertGMTTimestamp(Timestamp gmtTimestamp,
                                              int hourOffset) {
    return new Timestamp(gmtTimestamp.getTime() + hourOffset * HOUR);
  }

  public static Timestamp getCurrentGMTTimestampExpiredYear(int offsetYear) {
    //return new Timestamp(System.currentTimeMillis() + offsetYear*(365*24*60*60*1000));
    Calendar now = Calendar.getInstance();
    now.add(Calendar.YEAR, offsetYear);
    return new Timestamp(now.getTime().getTime());
  }

  public static Timestamp getCurrentGMTTimestampExpiredMonth(int offsetMonth) {
    Calendar now = Calendar.getInstance();
    now.add(Calendar.MONTH, offsetMonth);
    return new Timestamp(now.getTime().getTime());
  }

  /**
   * 在当前的日期前加上N天
   * @param day int 天数
   * @return Date
   */
  public static Date addDay(int day) {
    java.util.Date date1 = new Date();
    long Time = (date1.getTime() / 1000) + 60 * 60 * 24 * day;
    date1.setTime(Time * 1000);
    return date1;
  }

  /**
   * 计算两个时间之间的天数
   * @param d1 Date
   * @param d2 Date
   * @return long
   */
  public static long getDaysFromTwoDate(Date d1, Date d2) {
    long day = (d1.getTime() - d2.getTime()) / (24 * 60 * 60 * 1000);
    return day;
  }

  public static Date getLastSunday() {
    String sdate = getTime("yyyy-MM-dd");
    int syear = Integer.parseInt(sdate.substring(0, 4));
    int smonth = Integer.parseInt(sdate.substring(5, 7));
    int sday = Integer.parseInt(sdate.substring(8, 10));
    GregorianCalendar cal = new GregorianCalendar();
    cal.set(syear, smonth, sday);
    int week = cal.get(java.util.Calendar.DAY_OF_WEEK); //1为星期天
    return addDay( - (week + 6));
  }

  public static Date getLastSaturday() {
    String sdate = getTime("yyyy-MM-dd");
    int syear = Integer.parseInt(sdate.substring(0, 4));
    int smonth = Integer.parseInt(sdate.substring(5, 7));
    int sday = Integer.parseInt(sdate.substring(8, 10));
    GregorianCalendar cal = new GregorianCalendar();
    cal.set(syear, smonth, sday);
    int week = cal.get(java.util.Calendar.DAY_OF_WEEK); //1为星期天
    return addDay( - (week));
  }

  public static String getlastMonth() {
    String sdate = getTime("yyyy-MM-dd");
    int syear = Integer.parseInt(sdate.substring(0, 4));
    int smonth = Integer.parseInt(sdate.substring(5, 7));
    smonth = smonth - 1;
    if (smonth == 0) {
      smonth = 12;
      syear = syear - 1;
    }
    return syear + "-" + smonth + "-01";
  }

  public static String getThisMonthStart() {
    String sdate = getTime("yyyy-MM-dd");
    int syear = Integer.parseInt(sdate.substring(0, 4));
    int smonth = Integer.parseInt(sdate.substring(5, 7));
    return syear + "-" + smonth + "-01";
  }

  /**
   * 当日属于一年的第几周
   * @return int
   */
  public static int getWeekOfYeah() {
    Calendar calendar = Calendar.getInstance();
   
    int week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
    return week;
  }

  /**
   * 得到一个星期的开始
   * @return Date
   */
  public static Date weekStart() {
    Date date = new Date();
    Calendar calendar = Calendar.getInstance();
    int week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
    Date dateBegin = new Date();
    dateBegin.setTime(date.getTime() - (long) (week) * 24 * 60 * 60 * 1000);
    return dateBegin;
  }

  /**
   * 得到一个星期的结束
   * @return Date
   */
  public static Date weekEnd() {
    Date date = new Date();
    Calendar calendar = Calendar.getInstance();
    int week = calendar.get(Calendar.DAY_OF_WEEK) - 1;
    Date dateEnd = new Date();
    dateEnd.setTime(date.getTime() + (long) (6 - week) * 24 * 60 * 60 * 1000);
    return dateEnd;
  }

  /**
   * 得到某年第n个星期的星期天
   * @param year int
   * @param week int
   * @return Date
   */
  public static Date getDateByYearAndWeekstart(int year, int week) { //星期日。第一天
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.WEEK_OF_YEAR, week);
    calendar.set(Calendar.DAY_OF_WEEK, 1);
    return calendar.getTime();
  }

  public static String getQuarter(String month) {
      if (!StringUtils.hasText(month) && !StringUtils.isNumeric(month)) {
          month = "1";
      }
      int m = Integer.parseInt(month);
      if (m <= 12 && m >= 10) {
          return "4";
      } else if (m <= 9 && m >= 7) {
          return "3";
      } else if (m <= 6 && m >= 4) {
          return "2";
      } else {
          return "1";
      }
  }

  public static String getQuarter(){
      String month=getTime("M");
      return getQuarter(month);
  }

  public static String getQuarterCn(){
      String month=getTime("M");
      return getQuarterCn(month);
  }

  public static String getQuarterCn(String month) {
      if (!StringUtils.hasText(month) && !StringUtils.isNumeric(month)) {
          month = "1";
      }
      int m = Integer.parseInt(month);
      if (m <= 12 && m >= 10) {
          return "四";
      } else if (m <= 9 && m >= 7) {
          return "三";
      } else if (m <= 6 && m >= 4) {
          return "二";
      } else {
          return "一";
      }
  }

  /**
   * 得到某年第n个星期的星期六
   * @param year int
   * @param week int
   * @return Date
   */
  public static Date getDateByYearAndWeekend(int year, int week) { //星期六。最后一天
    Calendar calendar = Calendar.getInstance();
    calendar.set(Calendar.YEAR, year);
    calendar.set(Calendar.WEEK_OF_YEAR, week);
    calendar.set(Calendar.DAY_OF_WEEK, 0);
    return calendar.getTime();
  }

  public static void main(String args[]) {
   String stime="2007-08-24";
   String etime="2007-08-28";
   //System.out.println(DateUtils.compareTime(etime,stime));
   //System.out.println(DateUtils.getTime("M"));
   Float a=Float.valueOf("1");
   Float b=Float.valueOf("1.9");
  }

}