Java日期工具类

public class DateUtil
{
//默认显示日期的格式
public static final String DATAFORMAT_STR = "yyyy-MM-dd";

//默认显示日期的格式
public static final String YYYY_MM_DATAFORMAT_STR = "yyyy-MM";

//默认显示日期时间的格式
public static final String DATATIMEF_STR = "yyyy-MM-dd HH:mm:ss";

//默认显示简体中文日期的格式
public static final String ZHCN_DATAFORMAT_STR = "yyyy年MM月dd日";

//默认显示简体中文日期时间的格式
public static final String ZHCN_DATATIMEF_STR = "yyyy年MM月dd日HH时mm分ss秒";

//默认显示简体中文日期时间的格式
public static final String ZHCN_DATATIMEF_STR_4yMMddHHmm = "yyyy年MM月dd日HH时mm分";

private static DateFormat dateFormat = null;

private static DateFormat dateTimeFormat = null;

private static DateFormat zhcnDateFormat = null;

private static DateFormat zhcnDateTimeFormat = null;
static
{
dateFormat = new SimpleDateFormat(DATAFORMAT_STR);
dateTimeFormat = new SimpleDateFormat(DATATIMEF_STR);
zhcnDateFormat = new SimpleDateFormat(ZHCN_DATAFORMAT_STR);
zhcnDateTimeFormat = new SimpleDateFormat(ZHCN_DATATIMEF_STR);
}

private static DateFormat getDateFormat(String formatStr)
{
if (formatStr.equalsIgnoreCase(DATAFORMAT_STR))
{
return dateFormat;
}
else
if (formatStr.equalsIgnoreCase(DATATIMEF_STR))
{
return dateTimeFormat;
}
else
if (formatStr.equalsIgnoreCase(ZHCN_DATAFORMAT_STR))
{
return zhcnDateFormat;
}
else
if (formatStr.equalsIgnoreCase(ZHCN_DATATIMEF_STR))
{
return zhcnDateTimeFormat;
}
else
{
return new SimpleDateFormat(formatStr);
}
}

/**
* 按照默认显示日期时间的格式"yyyy-MM-dd HH:mm:ss"，转化dateTimeStr为Date类型
* dateTimeStr必须是"yyyy-MM-dd HH:mm:ss"的形式
* @param dateTimeStr
* @return
*/
public static Date getDate(String dateTimeStr)
{
return getDate(dateTimeStr, DATATIMEF_STR);
}

/**
* 按照默认formatStr的格式，转化dateTimeStr为Date类型
* dateTimeStr必须是formatStr的形式
* @param dateTimeStr
* @param formatStr
* @return
*/
public static Date getDate(String dateTimeStr, String formatStr)
{
try
{
if (dateTimeStr == null || dateTimeStr.equals(""))
{
return null;
}
DateFormat sdf = getDateFormat(formatStr);
java.util.Date d = sdf.parse(dateTimeStr);
return d;
}
catch (ParseException e)
{
throw new RuntimeException(e);
}
}

/**
* 将YYYYMMDD转换成Date日期
* @param date
* @return
* @throws BusinessException
*/
public static Date transferDate(String date) throws Exception
{
if (date == null || date.length() < 1)
return null;

if (date.length() != 8)
throw new Exception("日期格式错误");
String con = "-";

String yyyy = date.substring(0, 4);
String mm = date.substring(4, 6);
String dd = date.substring(6, 8);

int month = Integer.parseInt(mm);
int day = Integer.parseInt(dd);
if (month < 1 || month > 12 || day < 1 || day > 31)
throw new Exception("日期格式错误");

String str = yyyy + con + mm + con + dd;
return DateUtil.getDate(str, DateUtil.DATAFORMAT_STR);
}

/**
* 将YYYY－MM－DD日期转换成yyyymmdd格式字符串
* @param date
* @return
*/
public static String getYYYYMMDDDate(Date date)
{
if (date == null)
return null;
String yyyy = getYear(date) + "";
String mm = getMonth(date) + "";
String dd = getDay(date) + "";

mm = StringUtil.rightAlign(mm, 2, "0");
dd = StringUtil.rightAlign(dd, 2, "0");
return yyyy + mm + dd;
}

/**
* 将YYYY－MM－DD日期转换成YYYYMMDDHHMMSS格式字符串
* @param date
* @return
*/
public static String getYYYYMMDDHHMMSSDate(Date date)
{
if (date == null)
return null;
String yyyy = getYear(date) + "";
String mm = getMonth(date) + "";
String dd = getDay(date) + "";
String hh = getHour(date) + "";
String min = getMin(date) + "";
String ss = getSecond(date) + "";

mm = StringUtil.rightAlign(mm, 2, "0");
dd = StringUtil.rightAlign(dd, 2, "0");
hh = StringUtil.rightAlign(hh, 2, "0");
min = StringUtil.rightAlign(min, 2, "0");
ss = StringUtil.rightAlign(ss, 2, "0");

return yyyy + mm + dd + hh + min + ss;
}

/**
* 将YYYY－MM－DD日期转换成yyyymmdd格式字符串
* @param date
* @return
*/
public static String getYYYYMMDDDate(String date)
{
return getYYYYMMDDDate(getDate(date, DATAFORMAT_STR));
}

/**
* 将Date转换成字符串“yyyy-mm-dd hh:mm:ss”的字符串
* @param date
* @return
*/
public static String dateToDateString(Date date)
{
return dateToDateString(date, DATATIMEF_STR);
}

/**
* 将Date转换成formatStr格式的字符串
* @param date
* @param formatStr
* @return
*/
public static String dateToDateString(Date date, String formatStr)
{
DateFormat df = getDateFormat(formatStr);
return df.format(date);
}

/**
* 返回一个yyyy-MM-dd HH:mm:ss 形式的日期时间字符串中的HH:mm:ss
* @param dateTime
* @return
*/
public static String getTimeString(String dateTime)
{
return getTimeString(dateTime, DATATIMEF_STR);
}

/**
* 返回一个formatStr格式的日期时间字符串中的HH:mm:ss
* @param dateTime
* @param formatStr
* @return
*/
public static String getTimeString(String dateTime, String formatStr)
{
Date d = getDate(dateTime, formatStr);
String s = dateToDateString(d);
return s.substring(DATATIMEF_STR.indexOf('H'));
}

/**
* 获取当前日期yyyy-MM-dd的形式
* @return
*/
public static String getCurDate()
{
//return dateToDateString(new Date(),DATAFORMAT_STR);
return dateToDateString(Calendar.getInstance().getTime(), DATAFORMAT_STR);
}

/**
* 获取当前日期yyyy年MM月dd日的形式
* @return
*/
public static String getCurZhCNDate()
{
return dateToDateString(new Date(), ZHCN_DATAFORMAT_STR);
}

/**
* 获取当前日期时间yyyy-MM-dd HH:mm:ss的形式
* @return
*/
public static String getCurDateTime()
{
return dateToDateString(new Date(), DATATIMEF_STR);
}

/**
* 获取当前日期时间yyyy年MM月dd日HH时mm分ss秒的形式
* @return
*/
public static String getCurZhCNDateTime()
{
return dateToDateString(new Date(), ZHCN_DATATIMEF_STR);
}

/**
* 获取日期d的days天后的一个Date
* @param d
* @param days
* @return
*/
public static Date getInternalDateByDay(Date d, int days)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
now.add(Calendar.DATE, days);
return now.getTime();
}

public static Date getInternalDateByMon(Date d, int months)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
now.add(Calendar.MONTH, months);
return now.getTime();
}

public static Date getInternalDateByYear(Date d, int years)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
now.add(Calendar.YEAR, years);
return now.getTime();
}

public static Date getInternalDateBySec(Date d, int sec)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
now.add(Calendar.SECOND, sec);
return now.getTime();
}

public static Date getInternalDateByMin(Date d, int min)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
now.add(Calendar.MINUTE, min);
return now.getTime();
}

public static Date getInternalDateByHour(Date d, int hours)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
now.add(Calendar.HOUR_OF_DAY, hours);
return now.getTime();
}

/**
* 根据一个日期字符串，返回日期格式，目前支持4种
* 如果都不是，则返回null
* @param DateString
* @return
*/
public static String getFormateStr(String DateString)
{
String patternStr1 = "[0-9]{4}-[0-9]{1,2}-[0-9]{1,2}"; //"yyyy-MM-dd"
String patternStr2 = "[0-9]{4}-[0-9]{1,2}-[0-9]{1,2}\\s[0-9]{1,2}:[0-9]{1,2}:[0-9]{1,2}"; //"yyyy-MM-dd HH:mm:ss";
String patternStr3 = "[0-9]{4}年[0-9]{1,2}月[0-9]{1,2}日";//"yyyy年MM月dd日"
String patternStr4 = "[0-9]{4}年[0-9]{1,2}月[0-9]{1,2}日[0-9]{1,2}时[0-9]{1,2}分[0-9]{1,2}秒";//"yyyy年MM月dd日HH时mm分ss秒"

Pattern p = Pattern.compile(patternStr1);
Matcher m = p.matcher(DateString);
boolean b = m.matches();
if (b)
return DATAFORMAT_STR;
p = Pattern.compile(patternStr2);
m = p.matcher(DateString);
b = m.matches();
if (b)
return DATATIMEF_STR;

p = Pattern.compile(patternStr3);
m = p.matcher(DateString);
b = m.matches();
if (b)
return ZHCN_DATAFORMAT_STR;

p = Pattern.compile(patternStr4);
m = p.matcher(DateString);
b = m.matches();
if (b)
return ZHCN_DATATIMEF_STR;
return null;
}

/**
* 将一个"yyyy-MM-dd HH:mm:ss"字符串，转换成"yyyy年MM月dd日HH时mm分ss秒"的字符串
* @param dateStr
* @return
*/
public static String getZhCNDateTime(String dateStr)
{
Date d = getDate(dateStr);
return dateToDateString(d, ZHCN_DATATIMEF_STR);
}

/**
* 将一个"yyyy-MM-dd"字符串，转换成"yyyy年MM月dd日"的字符串
* @param dateStr
* @return
*/
public static String getZhCNDate(String dateStr)
{
Date d = getDate(dateStr, DATAFORMAT_STR);
return dateToDateString(d, ZHCN_DATAFORMAT_STR);
}

/**
* 将dateStr从fmtFrom转换到fmtTo的格式
* @param dateStr
* @param fmtFrom
* @param fmtTo
* @return
*/
public static String getDateStr(String dateStr, String fmtFrom, String fmtTo)
{
Date d = getDate(dateStr, fmtFrom);
return dateToDateString(d, fmtTo);
}

/**
* 比较两个"yyyy-MM-dd HH:mm:ss"格式的日期，之间相差多少毫秒,time2-time1
* @param time1
* @param time2
* @return
*/
public static long compareDateStr(String time1, String time2)
{
Date d1 = getDate(time1);
Date d2 = getDate(time2);
return d2.getTime() - d1.getTime();
}

/**
* 将小时数换算成返回以毫秒为单位的时间
* @param hours
* @return
*/
public static long getMicroSec(BigDecimal hours)
{
BigDecimal bd;
bd = hours.multiply(new BigDecimal(3600 * 1000));
return bd.longValue();
}

/**
* 获取Date中的分钟
* @param d
* @return
*/
public static int getMin(Date d)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
return now.get(Calendar.MINUTE);
}

/**
* 获取Date中的小时(24小时)
* @param d
* @return
*/
public static int getHour(Date d)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
return now.get(Calendar.HOUR_OF_DAY);
}

/**
* 获取Date中的秒
* @param d
* @return
*/
public static int getSecond(Date d)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
return now.get(Calendar.SECOND);
}

/**
* 获取xxxx-xx-xx的日
* @param d
* @return
*/
public static int getDay(Date d)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
return now.get(Calendar.DAY_OF_MONTH);
}

/**
* 获取月份，1-12月
* @param d
* @return
*/
public static int getMonth(Date d)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
return now.get(Calendar.MONTH) + 1;
}

/**
* 获取19xx,20xx形式的年
* @param d
* @return
*/
public static int getYear(Date d)
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
now.setTime(d);
return now.get(Calendar.YEAR);
}

/**
* 得到d的上个月的年份+月份,如200505
* @return
*/
public static String getYearMonthOfLastMon(Date d)
{
Date newdate = getInternalDateByMon(d, -1);
String year = String.valueOf(getYear(newdate));
String month = String.valueOf(getMonth(newdate));
return year + month;
}

/**
* 得到当前日期的年和月如200509
* @return String
*/
public static String getCurYearMonth()
{
Calendar now = Calendar.getInstance(TimeZone.getDefault());
String DATE_FORMAT = "yyyyMM";
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat(DATE_FORMAT);
sdf.setTimeZone(TimeZone.getDefault());
return (sdf.format(now.getTime()));
}

public static Date getNextMonth(String year, String month)
{
String datestr = year + "-" + month + "-01";
Date date = getDate(datestr, DATAFORMAT_STR);
return getInternalDateByMon(date, 1);
}

public static Date getLastMonth(String year, String month)
{
String datestr = year + "-" + month + "-01";
Date date = getDate(datestr, DATAFORMAT_STR);
return getInternalDateByMon(date, -1);
}

/**
* 得到日期d，按照页面日期控件格式，如"2001-3-16"
* @param d
* @return
*/
public static String getSingleNumDate(Date d)
{
return dateToDateString(d, DATAFORMAT_STR);
}

/**
* 得到d半年前的日期,"yyyy-MM-dd"
* @param d
* @return
*/
public static String getHalfYearBeforeStr(Date d)
{
return dateToDateString(getInternalDateByMon(d, -6), DATAFORMAT_STR);
}

/**
* 得到当前日期D的月底的前/后若干天的时间,<0表示之前，>0表示之后
* @param d
* @param days
* @return
*/
public static String getInternalDateByLastDay(Date d, int days)
{

return dateToDateString(getInternalDateByDay(d, days), DATAFORMAT_STR);
}

/**
* 日期中的年月日相加
*  @param field int  需要加的字段  年 月 日
* @param amount int 加多少
* @return String
*/
public static String addDate(int field, int amount)
{
int temp = 0;
if (field == 1)
{
temp = Calendar.YEAR;
}
if (field == 2)
{
temp = Calendar.MONTH;
}
if (field == 3)
{
temp = Calendar.DATE;
}

String Time = "";
try
{
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd");
Calendar cal = Calendar.getInstance(TimeZone.getDefault());
cal.add(temp, amount);
Time = sdf.format(cal.getTime());
return Time;
}
catch (Exception e)
{
e.printStackTrace();
return null;
}

}

/**
* 获得系统当前月份的天数
* @return
*/
public static int getCurentMonthDay()
{
Date date = Calendar.getInstance().getTime();
return getMonthDay(date);
}

/**
* 获得指定日期月份的天数
* @return
*/
public static int getMonthDay(Date date)
{
Calendar c = Calendar.getInstance();
c.setTime(date);
return c.getActualMaximum(Calendar.DAY_OF_MONTH);

}

/**
* 获得指定日期月份的天数  yyyy-mm-dd
* @return
*/
public static int getMonthDay(String date)
{
Date strDate = getDate(date, DATAFORMAT_STR);
return getMonthDay(strDate);

}

public static String getStringDate(Calendar cal)
{

SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
return format.format(cal.getTime());
}

/**
* @param args
*/
public static void main(String[] args)
{
// //System.out.print(DateUtil.getDate("04:04:04","HH:mm:ss"));
// System.out.print("\n"+DateUtil.getCurZhCNDateTime());
// System.out.print("\n"+getFormateStr(DateUtil.getCurDate()));
// System.out.print("\n"+compareDateStr("1900-1-1 1:1:2","1900-1-1 1:1:3"));
// System.out.print("\n"+getDay(new Date()));
// System.out.print("\n"+getMonth(new Date()));
// System.out.print("\n"+getYear(new Date()));
// System.out.print("\n"+getMin(new Date()));
//// System.out.print("\n"+new Date().getSeconds());
/*Date d1 = new Date(2007,11,30);
Date d2 = new Date(2007,12,1);
if(d2.compareTo(d1)>0){
   System.out.println("d2大于d1");
}else{
   System.out.println("d2小于d1");
}*/


System.out.println(addDate(1, 1));
System.out.println(addDate(2, 1));
System.out.println(addDate(3, 1));

System.out.println(getYYYYMMDDHHMMSSDate(new Date()));

System.out.println(getCurentMonthDay());

}

}