一个操作时间的类

package com.lhcard.common;

/**
 * <p>Title: 时间格式转化与计算</p>
 */

import java.util.Calendar;
import java.util.Date;
import java.text.*;

public class DateTime {
  public DateTime() {
  }

  /**
   * 取得系统当前时间
   * @return String yyyy-mm-dd
   */
  public static String getCurrentDate() {
    Calendar rightNow = Calendar.getInstance();
    int year = rightNow.get(rightNow.YEAR);
    int month = rightNow.get(rightNow.MONTH) + 1;
    int day = rightNow.get(rightNow.DATE);
    return year + "-" + month + "-" + day;
  }

  /**
   * 取得系统当前时间
   * @return String yyyy年mm月dd日
   */
  public static String getCurrentDate1() {
    Calendar rightNow = Calendar.getInstance();
    int year = rightNow.get(rightNow.YEAR);
    int month = rightNow.get(rightNow.MONTH) + 1;
    int day = rightNow.get(rightNow.DATE);
    return year + "年" + month + "月" + day + "日";
  }

  /**
   * 取得系统当前时间
   * @return String yyyymmdd
   */
  public static String getCurrentDate2() {
    Calendar rightNow = Calendar.getInstance();
    int year = rightNow.get(rightNow.YEAR);
    int month = rightNow.get(rightNow.MONTH) + 1;
    int day = rightNow.get(rightNow.DATE);
    return year + "" + month + "" + day;
  }

  /**
   * 取得系统当前时间
   * @return String yyyy-mm
   */
  public static String getCurrentDate3() {
    Calendar rightNow = Calendar.getInstance();
    int year = rightNow.get(rightNow.YEAR);
    int month = rightNow.get(rightNow.MONTH) + 1;
    //int day = rightNow.get(rightNow.DATE);
    return year + "-" + month;
  }

  /**
   * 取得系统当前时间
   * @return String yyyyMMddhhmmss
   */
  public static String getCurrentDate4() {
     Calendar c = Calendar.getInstance();
         c.add(c.SECOND, 0);

         return "" + c.get(c.YEAR) + "" + (c.get(c.MONTH) + 1) + "" + c.get(c.DATE)+""+c.get(c.HOUR_OF_DAY)+""+c.get(c.MINUTE)+""+c.get(c.SECOND);

}

  /**
   * 取得系统当前时间
   * @return String yyyy-MM-dd hh:mm:ss
   */
 /* public String getCurrentDate5() {
    SimpleDateFormat simpleDateFormat =new SimpleDateFormat("yyyy-MM-dd hh:mm:ss");
    java.util.Date date = new java.util.Date();
    String time = simpleDateFormat.format(date);
    return time;
  }
*/
 /**
 * 取得系统当前时间
 * @return String yyyy-MM-dd hh:mm:ss
 */

    public  static String getCurrentDate5(){
        Calendar c = Calendar.getInstance();
        c.add(c.SECOND, 0);
        return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE)+" "+c.get(c.HOUR_OF_DAY)+":"+c.get(c.MINUTE)+":"+c.get(c.SECOND);
      }

      /**
       * 取得系统当前时间 常用于订单号
       * @return String yyyyMMddhhmmss
       */
      public static String getCurrentDate6() {
         Calendar c = Calendar.getInstance();
             c.add(c.SECOND, 0);
             String year=c.get(c.YEAR)+"";
             return "" + year.subSequence(2,year.length())+ "" + (c.get(c.MONTH) + 1) + "" + c.get(c.DATE)+"-"+c.get(c.HOUR_OF_DAY)+""+c.get(c.MINUTE)+""+c.get(c.SECOND)+"-"+c.get(c.MILLISECOND);

    }

 //YYYYMMDD
     public static String getCurrentDate7() {
          Calendar c = Calendar.getInstance();
              c.add(c.SECOND, 0);
              String year=c.get(c.YEAR)+"";
              int month=c.get(c.MONTH) + 1;
              String strmonth=month+"";
              if(month<10){
                 strmonth="0"+month;
              }
              int day=c.get(c.DATE);
              String strday=day+"";
              if(day<10){
                 strday="0"+day;
              }
              return "" + year+ "" + strmonth + "" + strday;

     }
     //hhmmsswww
     public static String getCurrentDate8() {
          Calendar c = Calendar.getInstance();
              c.add(c.SECOND, 0);
              int hh=c.get(c.HOUR_OF_DAY);
              String strhh=hh+"";
              if(hh<10){
                 strhh="0"+hh;
              }
              int mm=c.get(c.MINUTE);
              String strmm=mm+"";
              if(mm<10){
                 strmm="0"+mm;
              }
              int ss=c.get(c.SECOND);
              String strss=ss+"";
              if(ss<10){
                 strss="0"+ss;
              }
              int www=c.get(c.MILLISECOND);
              String strwww=www+"";
              if(www<10){
                 strwww="00"+www;
              }if(9<www&&www<100){
                 strwww="0"+www;
              }





              return strhh+""+strmm+""+strss+""+strwww;

     }

  /**
   * 取得系统当前时间前n个月的相对应的一天
   * @param n int
   * @return String yyyy-mm-dd
   */
  public static String getNMonthBeforeCurrentDay(int n) {
    Calendar c = Calendar.getInstance();
    c.add(c.MONTH, -n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

  }

  /**
   * 取得系统当前时间后n个月的相对应的一天
   * @param n int
   * @return String  yyyy-mm-dd
   */
  public static String getNMonthAfterCurrentDay(int n) {
    Calendar c = Calendar.getInstance();
    c.add(c.MONTH, n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

  }

  /**
   * 取得系统当前时间前n天
   * @param n int
   * @return String yyyy-mm-dd
   */
  public static String getNDayBeforeCurrentDate(int n) {
    Calendar c = Calendar.getInstance();
    c.add(c.DAY_OF_MONTH, -n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);
  }

  /**
   * 取得系统当前时间后n天
   * @param n int
   * @return String yyyy-mm-dd
   */
  public static String getNDayAfterCurrentDate(int n) {
    Calendar c = Calendar.getInstance();
    c.add(c.DAY_OF_MONTH, n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);
  }
  public String getNDayAfterCurrentDate1(int n) {
    Calendar c = Calendar.getInstance();
    c.add(c.DAY_OF_MONTH, n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE)+" "+c.get(c.HOUR_OF_DAY)+":"+c.get(c.MINUTE)+":"+c.get(c.SECOND);
  }


  //---------------------------------------------------------------------
  //取过去一个时间对应的系统当年的一天
  public static String getCurrentDateAfterPastDate(String sPastDate) {
    if (sPastDate != null && !sPastDate.equals("")) {
      Date date = switchStringToDate(sPastDate);
      Calendar c = Calendar.getInstance();
      c.setTime(date);
      int iPastYear = c.get(c.YEAR);
      Calendar c1 = Calendar.getInstance();
      int iCurrentYear = c1.get(c1.YEAR);
      c.add(c.YEAR, iCurrentYear - iPastYear);
      return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" +
          c.get(c.DATE);
    }
    else {
      return null;
    }
  }

  /**
   * 将一个日期字符串转化成日期
   * @param sDate String
   * @return Date yyyy-mm-dd
   */
  public static Date switchStringToDate(String sDate) {
    Date date = null;
    try {
      SimpleDateFormat df = new SimpleDateFormat("yyyy-MM-dd");
      date = df.parse(sDate);

    }
    catch (Exception e) {
      System.out.println("日期转换失败:" + e.getMessage());
    }
    return date;
  }

  /**
   * 输入两个字符串型的日期，比较两者的大小
   * @param fromDate String
   * @param toDate String
   * @return boolean before为true
   */
  public static boolean compareTwoDateBigOrSmall(String fromDate, String toDate) {
    Date dateFrom = switchStringToDate(fromDate);
    Date dateTo = switchStringToDate(toDate);
    if (dateFrom.before(dateTo)) {
      return true;
    }
    else {
      return false;
    }
  }

  /**
   * 将一个日期字符串转化成Calendar
   * @param sDate String
   * @return Calendar
   */
  public static Calendar switchStringToCalendar(String sDate) {
    Date date = switchStringToDate(sDate);
    Calendar c = Calendar.getInstance();
    c.setTime(date);
    return c;
  }

  /**
   * 将一个日期转化成Calendar
   * @param date Date
   * @return Calendar
   */
  public static Calendar switchStringToCalendar(Date date) {
    Calendar c = Calendar.getInstance();
    c.setTime(date);
    return c;
  }

  public static String string2Date(String dateString)
  throws java.lang.Exception {
    /*DateFormat dateFormat;
    dateFormat = new SimpleDateFormat("yyyy-MM-dd kk:mm:ss");
    dateFormat.setLenient(false);
    java.util.Date timeDate = dateFormat.parse(dateString);//util类型
    //java.sql.Date dateTime = new java.sql.Date(timeDate.getTime());//sql类型
    java.sql.Timestamp dateTime = new java.sql.Timestamp(timeDate.getTime());//Timestamp类型
    */
    SimpleDateFormat newk = new SimpleDateFormat ("yyyy.MM.dd hh:mm:ss");
   SimpleDateFormat old = new SimpleDateFormat("MMM dd hh:mm:ss yyyy");

   String strDate = "Mar 22 00:42:00 2002";
   Date d = old.parse(strDate);
   System.out.println(newk.format(d));

    return newk.format(d);
  }



  /**
   * 取得某个时间前n个月的相对应的一天
   * @param sDate String
   * @param n int
   * @return String yyyy-mm-dd
   */
  public static String getNMonthBeforeOneDay(String sDate, int n) {
    Calendar c = switchStringToCalendar(sDate);
    c.add(c.MONTH, -n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

  }

  //取得某个时间后n个月的相对应的一天
  public static String getNMonthAfterOneDay(String sDate, int n) {
    Calendar c = switchStringToCalendar(sDate);
    c.add(c.MONTH, n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);

  }

  //取得某个时间前n天,格式为yyyy-mm-dd
  public static String getNDayBeforeOneDate(String sDate, int n) {
    Calendar c = switchStringToCalendar(sDate);
    c.add(c.DAY_OF_MONTH, -n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);
  }

  //取得某个时间后n天,格式为yyyy-mm-dd
  public static String getNDayAfterOneDate(String sDate, int n) {
    Calendar c = switchStringToCalendar(sDate);
    c.add(c.DAY_OF_MONTH, n);
    return "" + c.get(c.YEAR) + "-" + (c.get(c.MONTH) + 1) + "-" + c.get(c.DATE);
  }

  //判断系统当前时间是不是润年
  public static boolean isRunNian() {
    java.util.Calendar rightNow = java.util.Calendar.getInstance();
    int year = rightNow.get(rightNow.YEAR);
    if (0 == year % 4 && (year % 100 != 0 || year % 400 == 0)) {
      return true;
    }
    else {
      return false;
    }

  }

  public static void main(String args[]) {
    DateTime a = new DateTime();
    try{
      //System.out.println(a.getNDayAfterCurrentDate(1));
     // System.out.println(a.getNDayAfterCurrentDate(0));
     // System.out.println(a.compareTwoDateBigOrSmall("2005-12-27 11:01:45.0","2005-12-10 13:16:58.0"));
      System.out.println(a.switchStringToDate("2007-1-5"));
    }catch(Exception e){System.err.println();}

  }
}