java日期工具类（Long型，Date型，yyyyMMdd型）等

import java.sql.Timestamp;
import java.text.ParsePosition;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
import java.util.regex.Pattern;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class DateUtils {
protected static Log logger = LogFactory.getLog(DateUtils.class);

// 格式：年－月－日 小时：分钟：秒
public static final String FORMAT_ONE = "yyyy-MM-dd HH:mm:ss";

// 格式：年－月－日 小时：分钟
public static final String FORMAT_TWO = "yyyy-MM-dd HH:mm";

// 格式：年月日 小时分钟秒
public static final String FORMAT_THREE = "yyyyMMdd-HHmmss";

// 格式：年－月－日
public static final String LONG_DATE_FORMAT = "yyyy-MM-dd";

// 格式：月－日
public static final String SHORT_DATE_FORMAT = "MM-dd";

// 格式：小时：分钟：秒
public static final String LONG_TIME_FORMAT = "HH:mm:ss";

//格式：年-月
public static final String MONTG_DATE_FORMAT = "yyyy-MM";

// 年的加减
public static final int SUB_YEAR = Calendar.YEAR;

// 月加减
public static final int SUB_MONTH = Calendar.MONTH;

// 天的加减
public static final int SUB_DAY = Calendar.DATE;

// 小时的加减
public static final int SUB_HOUR = Calendar.HOUR;

// 分钟的加减
public static final int SUB_MINUTE = Calendar.MINUTE;

// 秒的加减
public static final int SUB_SECOND = Calendar.SECOND;

static final String dayNames[] = { "星期日", "星期一", "星期二", "星期三", "星期四","星期五", "星期六" };

@SuppressWarnings("unused")
private static final SimpleDateFormat timeFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");

public DateUtils() {}

/**
* 把符合日期格式的字符串转换为日期类型
*
* @param dateStr
* @return
*/
public static java.util.Date stringtoDate(String dateStr, String format) {
Date d = null;
SimpleDateFormat formater = new SimpleDateFormat(format);
try {
formater.setLenient(false);
d = formater.parse(dateStr);
} catch (Exception e) {
// log.error(e);
d = null;
}
return d;
}

/**
* 把符合日期格式的字符串转换为日期类型
*/
public static java.util.Date stringtoDate(String dateStr, String format,
ParsePosition pos) {
Date d = null;
SimpleDateFormat formater = new SimpleDateFormat(format);
try {
formater.setLenient(false);
d = formater.parse(dateStr, pos);
} catch (Exception e) {
d = null;
}
return d;
}

/**
* 把日期转换为字符串
*
* @param date
* @return
*/
public static String dateToString(java.util.Date date, String format) {
String result = "";
SimpleDateFormat formater = new SimpleDateFormat(format);
try {
result = formater.format(date);
} catch (Exception e) {
// log.error(e);
}
return result;
}

/**
* 获取当前时间的指定格式
*
* @param format
* @return
*/
public static String getCurrDate(String format) {
return dateToString(new Date(), format);
}

/**
*
* @param dateStr
* @param amount
* @return
*/
public static String dateSub(int dateKind, String dateStr, int amount) {
Date date = stringtoDate(dateStr, FORMAT_ONE);
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
calendar.add(dateKind, amount);
return dateToString(calendar.getTime(), FORMAT_ONE);
}

/**
* 两个日期相减
*
* @param firstTime
* @param secTime
* @return 相减得到的秒数
*/
public static long timeSub(String firstTime, String secTime) {
long first = stringtoDate(firstTime, FORMAT_ONE).getTime();
long second = stringtoDate(secTime, FORMAT_ONE).getTime();
return (second - first) / 1000;
}

/**
* 获得某月的天数
*
* @param year
*          int
* @param month
*          int
* @return int
*/
public static int getDaysOfMonth(String year, String month) {
int days = 0;
if (month.equals("1") || month.equals("3") || month.equals("5")
|| month.equals("7") || month.equals("8") || month.equals("10")
|| month.equals("12")) {
days = 31;
} else if (month.equals("4") || month.equals("6") || month.equals("9")
|| month.equals("11")) {
days = 30;
} else {
if ((Integer.parseInt(year) % 4 == 0 && Integer.parseInt(year) % 100 != 0)
|| Integer.parseInt(year) % 400 == 0) {
days = 29;
} else {
days = 28;
}
}

return days;
}

/**
* 获取某年某月的天数
*
* @param year
*          int
* @param month
*          int 月份[1-12]
* @return int
*/
public static int getDaysOfMonth(int year, int month) {
Calendar calendar = Calendar.getInstance();
calendar.set(year, month - 1, 1);
return calendar.getActualMaximum(Calendar.DAY_OF_MONTH);
}

/**
* 获得当前日期
*
* @return int
*/
public static int getToday() {
Calendar calendar = Calendar.getInstance();
return calendar.get(Calendar.DATE);
}

/**
* 获得当前月份
*
* @return int
*/
public static int getToMonth() {
Calendar calendar = Calendar.getInstance();
return calendar.get(Calendar.MONTH) + 1;
}

/**
* 获得当前年份
*
* @return int
*/
public static int getToYear() {
Calendar calendar = Calendar.getInstance();
return calendar.get(Calendar.YEAR);
}

/**
* 返回日期的天
*
* @param date
*          Date
* @return int
*/
public static int getDay(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.get(Calendar.DATE);
}

/**
* 返回日期的年
*
* @param date
*          Date
* @return int
*/
public static int getYear(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.get(Calendar.YEAR);
}

/**
* 返回日期的月份，1-12
*
* @param date
*          Date
* @return int
*/
public static int getMonth(Date date) {
Calendar calendar = Calendar.getInstance();
calendar.setTime(date);
return calendar.get(Calendar.MONTH) + 1;
}

/**
* 计算两个日期相差的天数，如果date2 > date1 返回正数，否则返回负数
*
* @param date1
*          Date
* @param date2
*          Date
* @return long
*/
public static long dayDiff(Date date1, Date date2) {
return (date2.getTime() - date1.getTime()) / 86400000;
}

/**
* 比较两个日期的年差
*
* @param befor
* @param after
* @return
*/
public static int yearDiff(String before, String after) {
Date beforeDay = stringtoDate(before, LONG_DATE_FORMAT);
Date afterDay = stringtoDate(after, LONG_DATE_FORMAT);
return getYear(afterDay) - getYear(beforeDay);
}

/**
* 比较指定日期与当前日期的差
*
* @param befor
* @param after
* @return
*/
public static int yearDiffCurr(String after) {
Date beforeDay = new Date();
Date afterDay = stringtoDate(after, LONG_DATE_FORMAT);
return getYear(beforeDay) - getYear(afterDay);
}

/**
* 比较指定日期与当前日期的差
* @param before
* @return
*/
public static long dayDiffCurr(String before) {
Date currDate = DateUtils.stringtoDate(currDay(), LONG_DATE_FORMAT);
Date beforeDate = stringtoDate(before, LONG_DATE_FORMAT);
return (currDate.getTime() - beforeDate.getTime()) / 86400000;

}

/**
* 获取每月的第一周
* @param year
* @param month
* @return
*/
public static int getFirstWeekdayOfMonth(int year, int month) {
Calendar c = Calendar.getInstance();
c.setFirstDayOfWeek(Calendar.SATURDAY); // 星期天为第一天
c.set(year, month - 1, 1);
return c.get(Calendar.DAY_OF_WEEK);
}

/**
* 获取每月的最后一周
* @param year
* @param month
* @return
*/
public static int getLastWeekdayOfMonth(int year, int month) {
Calendar c = Calendar.getInstance();
c.setFirstDayOfWeek(Calendar.SATURDAY); // 星期天为第一天
c.set(year, month - 1, getDaysOfMonth(year, month));
return c.get(Calendar.DAY_OF_WEEK);
}

/**
* 获得当前日期字符串，格式"yyyy-MM-dd HH:mm:ss"
*
* @return
*/
public static String getNow() {
Calendar today = Calendar.getInstance();
return dateToString(today.getTime(), FORMAT_ONE);
}

/**
* 根据生日获取星座
*
* @param birth
*          YYYY-mm-dd
* @return
*/
public static String getAstro(String birth) {
if (!isDate(birth)) {
birth = "2000" + birth;
}
if (!isDate(birth)) {
return "";
}
int month = Integer.parseInt(birth.substring(birth.indexOf("-") + 1,
birth.lastIndexOf("-")));
int day = Integer.parseInt(birth.substring(birth.lastIndexOf("-") + 1));
String s = "魔羯水瓶双鱼牡羊金牛双子巨蟹狮子处女天秤天蝎射手魔羯";
int[] arr = { 20, 19, 21, 21, 21, 22, 23, 23, 23, 23, 22, 22 };
int start = month * 2 - (day < arr[month - 1] ? 2 : 0);
return s.substring(start, start + 2) + "座";
}

/**
* 判断日期是否有效,包括闰年的情况
*
* @param date
*          YYYY-mm-dd
* @return
*/
public static boolean isDate(String date) {
StringBuffer reg = new StringBuffer("^((\\d{2}(([02468][048])|([13579][26]))-?((((0?");
reg.append("[13578])|(1[02]))-?((0?[1-9])|([1-2][0-9])|(3[01])))");
reg.append("|(((0?[469])|(11))-?((0?[1-9])|([1-2][0-9])|(30)))|");
reg.append("(0?2-?((0?[1-9])|([1-2][0-9])))))|(\\d{2}(([02468][12");
reg.append("35679])|([13579][01345789]))-?((((0?[13578])|(1[02]))");
reg.append("-?((0?[1-9])|([1-2][0-9])|(3[01])))|(((0?[469])|(11))");
reg.append("-?((0?[1-9])|([1-2][0-9])|(30)))|(0?2-?((0?[");
reg.append("1-9])|(1[0-9])|(2[0-8]))))))");
Pattern p = Pattern.compile(reg.toString());
return p.matcher(date).matches();
}

/**
* 取得指定日期过 months 月后的日期 (当 months 为负数表示指定月之前);
*
* @param date
*          日期 为null时表示当天
* @param month
*          相加(相减)的月数
*/
public static Date nextMonth(Date date, int months) {
Calendar cal = Calendar.getInstance();
if (date != null) {
cal.setTime(date);
}
cal.add(Calendar.MONTH, months);
return cal.getTime();
}

/**
* 取得指定日期过 day 天后的日期 (当 day 为负数表示指日期之前);
*
* @param date
*          日期 为null时表示当天
* @param month
*          相加(相减)的月数
*/
public static Date nextDay(Date date, int day) {
Calendar cal = Calendar.getInstance();
if (date != null) {
cal.setTime(date);
}
cal.add(Calendar.DAY_OF_YEAR, day);
return cal.getTime();
}

/**
* 取得距离今天 day 日的日期
* @param day
* @param format
* @return
* @author chenyz
*/
public static String nextDay(int day, String format) {
Calendar cal = Calendar.getInstance();
cal.setTime(new Date());
cal.add(Calendar.DAY_OF_YEAR, day);
return dateToString(cal.getTime(), format);
}

/**
* 取得指定日期过 day 周后的日期 (当 day 为负数表示指定月之前)
*
* @param date
*          日期 为null时表示当天
*/
public static Date nextWeek(Date date, int week) {
Calendar cal = Calendar.getInstance();
if (date != null) {
cal.setTime(date);
}
cal.add(Calendar.WEEK_OF_MONTH, week);
return cal.getTime();
}

/**
* 获取当前的日期(yyyy-MM-dd)
*/
public static String currDay() {
return DateUtils.dateToString(new Date(), DateUtils.LONG_DATE_FORMAT);
}

/**
* 获取昨天的日期
*
* @return
*/
public static String befoDay() {
return befoDay(DateUtils.LONG_DATE_FORMAT);
}

/**
* 根据时间类型获取昨天的日期
* @param format
* @return
* @author chenyz
*/
public static String befoDay(String format) {
return DateUtils.dateToString(DateUtils.nextDay(new Date(), -1), format);
}

/**
* 获取明天的日期
*/
public static String afterDay() {
return DateUtils.dateToString(DateUtils.nextDay(new Date(), 1),
DateUtils.LONG_DATE_FORMAT);
}

/**
* 取得当前时间距离1900/1/1的天数
*
* @return
*/
public static int getDayNum() {
int daynum = 0;
GregorianCalendar gd = new GregorianCalendar();
Date dt = gd.getTime();
GregorianCalendar gd1 = new GregorianCalendar(1900, 1, 1);
Date dt1 = gd1.getTime();
daynum = (int) ((dt.getTime() - dt1.getTime()) / (24 * 60 * 60 * 1000));
return daynum;
}

/**
* getDayNum的逆方法(用于处理Excel取出的日期格式数据等)
*
* @param day
* @return
*/
public static Date getDateByNum(int day) {
GregorianCalendar gd = new GregorianCalendar(1900, 1, 1);
Date date = gd.getTime();
date = nextDay(date, day);
return date;
}

/** 针对yyyy-MM-dd HH:mm:ss格式,显示yyyymmdd */
public static String getYmdDateCN(String datestr) {
if (datestr == null)
return "";
if (datestr.length() < 10)
return "";
StringBuffer buf = new StringBuffer();
buf.append(datestr.substring(0, 4)).append(datestr.substring(5, 7))
.append(datestr.substring(8, 10));
return buf.toString();
}

/**
* 获取本月第一天
*
* @param format
* @return
*/
public static String getFirstDayOfMonth(String format) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.DATE, 1);
return dateToString(cal.getTime(), format);
}

/**
* 获取本月最后一天
*
* @param format
* @return
*/
public static String getLastDayOfMonth(String format) {
Calendar cal = Calendar.getInstance();
cal.set(Calendar.DATE, 1);
cal.add(Calendar.MONTH, 1);
cal.add(Calendar.DATE, -1);
return dateToString(cal.getTime(), format);
}

/**
* @desc: 获取系统 Timestamp，如（2014-12-18 17:35:46.651）
* @return Timestamp
*/
public static Timestamp getCurrentSysTimestamp(){
Timestamp d = new Timestamp(System.currentTimeMillis());
return d;
}

//----------------------------------------以下是(Long和Date)(Long和yyyy-MM-dd)转换---------------------------------------------------

/**
* 获取当前时间的秒数 1970/01/01至今的秒数，,等于new Date().getTime()/1000
* @param date
* @return
* @throws Exception
*/
public static long getNowTimeStamp()
{
long stamp = 0L;
Date date1 = new Date();
Date date2 = null;
try {
date2 = (new SimpleDateFormat("yyyy/MM/dd HH:mm:ss")).parse("1970/01/01 08:00:00");
} catch (Exception e) {
e.printStackTrace();
}
stamp = (date1.getTime() - date2.getTime()) / 1000L;
return stamp;
}

/**
* 获取当前时间的毫秒数 1970/01/01至今的毫秒数,等于new Date().getTime()
* @param date
* @return
* @throws Exception
*/
public static long getNowTimeStampMs(){
long stamp = 0L;
Date date1 = new Date();
Date date2 = null;
try {
date2 = (new SimpleDateFormat("yyyy/MM/dd HH:mm:ss")).parse("1970/01/01 08:00:00");
} catch (Exception e) {
e.printStackTrace();
}
stamp = (date1.getTime() - date2.getTime());
return stamp;
}

/**
* 时间转换成秒 1970/01/01至今的秒数（Date转long），等于new Date().getTime()/1000
* @param date
* @return
* @throws Exception
*/
public static long getTimeStampByDate(Date date)
{
long stamp = 0L;
Date date1 = date;
Date date2 = null;
try {
date2 = (new SimpleDateFormat("yyyy/MM/dd HH:mm:ss")).parse("1970/01/01 08:00:00");
stamp = (date1.getTime() - date2.getTime()) / 1000L;
} catch (Exception e) {
stamp = 0L;
}

return stamp;
}

/**
* 时间转换成秒 1970/01/01至今的豪秒数（Date转long）
* @param date
* @return
* @throws Exception
*/
public static long getTimeStampMsByDate(Date date)
{
long stamp = 0L;
Date date1 = date;
Date date2 = null;
try {
date2 = (new SimpleDateFormat("yyyy/MM/dd HH:mm:ss")).parse("1970/01/01 08:00:00");
stamp = (date1.getTime() - date2.getTime());
} catch (Exception e) {
stamp = 0L;
}

return stamp;
}

/**
* 将时间由秒转换成指定格式，如(long转：yyyy-MM-dd HH:mm:ss)
* @param second
* @param format
* @return
* @throws Exception
*/
public static String getYYYYByTimeStamp(Long second, String format)
{
if(second==null||second==0){
return "";
}
Date da = null;
try {
da = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")).parse("1970-01-01 08:00:00");
} catch (Exception e) {
e.printStackTrace();
}
Date date = new Date(da.getTime() + second * 1000L);
return (new SimpleDateFormat(format)).format(date);
}
/**
* 将时间由毫秒转换成指定格式，如(long转：yyyy-MM-dd HH:mm:ss)
* @param second
* @param format
* @return
* @throws Exception
*/
public static String getYYYYbyTimeStampMs(Long second, String format)
{
if(second==null||second==0){
return "";
}
Date da = null;
try {
da = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss")).parse("1970-01-01 08:00:00");
} catch (Exception e) {
e.printStackTrace();
}
Date date = new Date(da.getTime() + second );
return (new SimpleDateFormat(format)).format(date);
}

/**
* 1970/01/01至今的秒数转换成Date
* @param TimeStamp
* @return
*/
public static Date getDateByTimeStamp(Long TimeStamp){
return new Date(TimeStamp*1000);
}

/**
* 1970/01/01至今的豪秒数转换成Date
* @param TimeStampMs
* @return
*/
public static Date getDateByTimeStampMs(Long TimeStampMs){
return new Date(TimeStampMs);
}

}