JAVA各种时间类型的取得

package com.hello.test;import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;import java.util.GregorianCalendar;import java.util.Locale;import java.util.MissingResourceException;import java.util.ResourceBundle;import org.apache.log4j.Logger;public class DateUtil {private static Logger log = Logger.getLogger(DateUtil.class);private static String defaultDatePattern = null;private static String timePattern = "HH:mm";public static Date getSystemTime() {Calendar now = Calendar.getInstance();return now.getTime();}public static synchronized String getDatePattern() {Locale locale = Locale.CHINA; // LocaleContextHolder.getLocale();try {defaultDatePattern = ResourceBundle.getBundle("yyyy-MM-dd", locale).getString("date.format");} catch (MissingResourceException mse) {defaultDatePattern = "yyyy-MM-dd";}return defaultDatePattern;}public static final String getDate(Date aDate) {SimpleDateFormat df = null;String returnValue = "";if (aDate != null) {df = new SimpleDateFormat(getDatePattern());returnValue = df.format(aDate);}return (returnValue);}public static final Date convertStringToDate(String aMask, String strDate) {SimpleDateFormat df = null;Date date = null;df = new SimpleDateFormat(aMask);if (log.isDebugEnabled()) {log.debug("converting '" + strDate + "' to date with mask '" + aMask + "'");}try {date = df.parse(strDate);} catch (ParseException pe) {log.error("ParseException: " + pe);}return (date);}public static String getTimeNow(Date theTime) {return getDateTime(timePattern, theTime);}public static Calendar getToday() throws ParseException {Date today = new Date();SimpleDateFormat df = new SimpleDateFormat(getDatePattern());// This seems like quite a hack (date -> string -> date),// but it works ;-)String todayAsString = df.format(today);Calendar cal = new GregorianCalendar();cal.setTime(convertStringToDate(todayAsString));return cal;}public static Date getMonday(Date date) {Calendar c = Calendar.getInstance();c.setTime(date);if (c.get(Calendar.DAY_OF_WEEK) == 1) {date = DateUtil.addDays(date, -7);c.setTime(date);}c.set(Calendar.DAY_OF_WEEK, Calendar.MONDAY);String mondayString = DateUtil.format(c.getTime(), "yyyy-MM-dd");mondayString = mondayString + " 00:00:00";return convertStringToDate("yyyy-MM-dd HH:mm:ss", mondayString);}public static Date getFriday(Date date) {Calendar c = Calendar.getInstance();c.setTime(date);c.set(Calendar.DAY_OF_WEEK, Calendar.FRIDAY);String fridayString = format(c.getTime(), "yyyy-MM-dd");fridayString = fridayString + " 23:59:59";return convertStringToDate("yyyy-MM-dd HH:mm:ss", fridayString);}public static final String getDateTime(String aMask, Date aDate) {SimpleDateFormat df = null;String returnValue = "";if (aDate == null) {log.error("aDate is null!");} else {df = new SimpleDateFormat(aMask);returnValue = df.format(aDate);}return (returnValue);}public static final String convertDateToString(Date aDate) {return getDateTime(getDatePattern(), aDate);}public static Date convertStringToDate(String strDate) {Date aDate = null;try {if (log.isDebugEnabled()) {log.debug("converting date with pattern: " + getDatePattern());}aDate = convertStringToDate(getDatePattern(), strDate);} catch (Exception pe) {log.error("Could not convert '" + strDate + "' to a date, throwing exception");}return aDate;}public static int dayDiff(Date first, Date second) {long msPerDay = 1000 * 60 * 60 * 24;long diff = (first.getTime() / msPerDay) - (second.getTime() / msPerDay);Long convertLong = new Long(diff);return convertLong.intValue();}public static long dayDiffMilSecond(Date first, Date second) {long diff = first.getTime() - second.getTime();Long convertLong = new Long(diff);return convertLong;}public static String format(Date date, String pattern) {if (date == null)return "";SimpleDateFormat formatter = new SimpleDateFormat(pattern);return formatter.format(date);}static public final Date addDays(Date target, int days) {long msPerDay = 1000 * 60 * 60 * 24; // 一天的毫秒数long msTarget = target.getTime(); // 返回从一个特定的日期（1970。。）到现在经过的毫秒数。long msSum = msTarget + (msPerDay * days);Date result = new Date();result.setTime(msSum); // 根据毫秒设置日期return result;}public static Date beforeDays(Date target, int days) {long msPerDay = 1000 * 60 * 60 * 24; // 一天的毫秒数long msTarget = target.getTime(); // 返回从一个特定的日期（1970。。）到现在经过的毫秒数。long msSum = msTarget - (msPerDay * days);Date result = new Date();result.setTime(msSum); // 根据毫秒设置日期return result;}public static Date formatString(String time, String format) {try {SimpleDateFormat formater = new SimpleDateFormat(format);return formater.parse(time);} catch (Exception e) {return null;}}public static Date getFirstDateOfMonth(Date date) {Calendar calendar = Calendar.getInstance();calendar.setTime(date);calendar.set(Calendar.DAY_OF_MONTH, 1);calendar.set(Calendar.HOUR_OF_DAY, 0);calendar.set(Calendar.MINUTE, 0);calendar.set(Calendar.SECOND, 0);return calendar.getTime();}public static Date getLastlyDateOfMonth(Date date) {Calendar calendar = Calendar.getInstance();calendar.setTime(date);int month = calendar.get(Calendar.MONTH);calendar.set(Calendar.MONTH, month + 1);calendar.set(Calendar.DAY_OF_MONTH, 1);calendar.set(Calendar.HOUR_OF_DAY, 23);calendar.set(Calendar.MINUTE, 59);calendar.set(Calendar.SECOND, 59);calendar.add(Calendar.DAY_OF_MONTH, -1);return calendar.getTime();}public static Date getFirstDateOfNextMonth(Date date) {Calendar calendar = Calendar.getInstance();calendar.setTime(date);int month = calendar.get(Calendar.MONTH);calendar.set(Calendar.MONTH, month + 1);calendar.set(Calendar.DAY_OF_MONTH, 1);calendar.set(Calendar.HOUR_OF_DAY, 0);calendar.set(Calendar.MINUTE, 0);calendar.set(Calendar.SECOND, 0);return calendar.getTime();}public static String getCurrentDayPath() {SimpleDateFormat sdf = new SimpleDateFormat("yyyy");Date now = new Date();String filePath = sdf.format(now) + "/";sdf = new SimpleDateFormat("MM");filePath += sdf.format(now) + "/";sdf = new SimpleDateFormat("dd");filePath += sdf.format(now) + "/";return filePath;}}

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