DateUtil时间工具类

 package utils;

 import java.text.ParseException;
 import java.text.SimpleDateFormat;
 import java.util.Calendar;
 import java.util.Date;
 import java.util.GregorianCalendar;

 public final class DateUtil{

 /** 默认的年月日 */
 public static final String defaultPattern = "yyyy-MM-dd";

 /** hour12HMSPattern年月日 时分秒 12小时制*/
 public static final String hour12HMSPattern = "yyyy-MM-dd hh:mm:ss";

 /** hour12HMPattern年月日 时分 12小时制*/
 public static final String hour12HMPattern = "yyyy-MM-dd hh:mm";

 /** hour12HPattern年月日 时 12小时制*/
 public static final String hour12HPattern = "yyyy-MM-dd hh";

 /** hour24HMSPattern年月日 时分秒 24小时制 */
 public static final String hour24HMSPattern = "yyyy-MM-dd HH:mm:ss";

 /** hour24HMPattern年月日 时分 24小时制*/
 public static final String hour24HMPattern = "yyyy-MM-dd HH:mm";

 /** hour24HPattern年月日 时 24小时制*/
 public static final String hour24HPattern = "yyyy-MM-dd HH";

 public static String daysBetween(Date startDate, Date endDate) {
 float d = endDate.getTime() - startDate.getTime();
 float dd = d / 86400000f;
 int ddd = (int)dd;

 float hh = (dd - ddd) * 24;
 int hhh = (int)hh;

 float mm = (hh - hhh) * 60;
 int mmm = (int)mm;

 float ss = (mm - mmm) * 60;
 int sss = (int)ss;
 return ddd + "天" + hhh + "小时" + mmm + "分" + sss + "秒";
 } 

 /**
 * 返回预设Format的当前日期字符串
 */
 public static String getToday() {
 Date today = new Date();
 return format(today);
 }

 public static String getYestoday() {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(new Date());
 cal1.add(Calendar.DATE, -1);
 return format(cal1.getTime());
 }

 public static String getTheDayBeforeYestoday() {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(new Date());
 cal1.add(Calendar.DATE, -2);
 return format(cal1.getTime());
 }

 public static String getPreviousDay3() {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(new Date());
 cal1.add(Calendar.DATE, -3);
 return format(cal1.getTime());
 }

 public static String getPreviousDay4() {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(new Date());
 cal1.add(Calendar.DATE, -4);
 return format(cal1.getTime());
 }

 /**
 * 用预设Format格式化Date成字符串
 */
 public static String format(Date date) {
 return format(date, defaultPattern);
 }

 /**
 * 使用参数Format格式化Date成字符串
 */
 public static String format(Date date, String pattern) {
 String returnValue = "";

 if (date != null) {
 SimpleDateFormat df = new SimpleDateFormat(pattern);
 returnValue = df.format(date);
 }

 return (returnValue);
 }

 /**
 * 使用预设格式将字符串转为Date
 */
 public static Date parse(String strDate) throws ParseException {
 return parse(strDate, defaultPattern);
 }

 public static Date parse(String strDate, String pattern)
 throws ParseException {
 SimpleDateFormat df = new SimpleDateFormat(pattern);
 return df.parse(strDate);
 }

 /**
 * 在日期上增加数个整月
 */
 public static Date addMonth(Date date, int n) {
 Calendar cal = Calendar.getInstance();
 cal.setTime(date);
 cal.add(Calendar.MONTH, n);
 return cal.getTime();
 }

 /**
 * 在日期上增加日
 */
 public static Date addDay(Date date, int n) {
 Calendar cal = Calendar.getInstance();
 cal.setTime(date);
 cal.add(Calendar.DATE, n);
 return cal.getTime();
 }

 public static String formatDateTime(Date date) {
 SimpleDateFormat outFormat = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");
 return outFormat.format(date);
 }

 @SuppressWarnings("static-access")
 public static String getEndOfMonth(String year, String month) {
 Calendar cal = Calendar.getInstance();
 cal.set(cal.YEAR, Integer.parseInt(year));
 cal.set(cal.MONTH, Integer.parseInt(month) - 1);
 return cal.getActualMaximum(cal.DAY_OF_MONTH) + "";
 }

 public static String addDays(String sdate, int n) throws ParseException
 {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(parse(sdate, defaultPattern));
 cal1.add(Calendar.DATE, n);
 return format(cal1.getTime());

 }

 public static String getFirstOfMonth() throws ParseException {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(new Date());
 cal1.set(5, 1);
 return format(cal1.getTime());

 }

 public static String getFirstOfMonth(String sDate) throws ParseException {
 Calendar cal1 = Calendar.getInstance();
 cal1.setTime(parse(sDate, defaultPattern));
 cal1.set(5, 1);
 return format(cal1.getTime());

 }

 /**
 * 获取年
 *
 * @param sdate
 * @return String
 */
 public static String getYear(String sdate) {
 String[] date = sdate.split("-");
 return date[0];
 }

 /**
 * 获取月
 *
 * @param sdate
 * @return String
 */
 public static String getMonth(String sdate) {
 String[] date = sdate.split("-");
 return date[1];
 }

 public static String getCurrentYear() {
 Calendar cale = Calendar.getInstance();
 return Integer.toString(cale.get(Calendar.YEAR));
 }

 public static String getCurrentMonth() {
 Calendar cale = Calendar.getInstance();
 int month = cale.get(Calendar.MONTH);
 month++;
 String sMonth = Integer.toString(month);
 if (month < 10)
 sMonth = "0" + month;
 return sMonth;
 }

 /**
 * 获取天
 *
 * @param sdate
 * @return String
 */
 public static String getDay(String sdate) {
 String[] date = sdate.split("-");
 return date[2];
 }

 public static String getFullDate(String date) {
 if (date != null && date.length() == 1)
 return "0" + date;
 return date;
 }

 public static String getSimpleDateString(String sdate) {
 return sdate.replace("-", "");
 }

 //把日期从字符弄转成日期型
 public static Date convertStringToDate(String pattern, String strDate)
 throws ParseException {
 Date aDate = null;
 aDate = parse(strDate, pattern);
 return aDate;
 }

 //根据指定格式得到当前日期的字符串
 public static String getTodayDate(String aMask){
 Date date = new Date();
 return getDateTime(aMask,date);
 }

 //根据指定格式得到指定日期的字符串
 public static String getDateTime(String aMask, Date aDate) {
 SimpleDateFormat df = null;
 String returnValue = "";
 df = new SimpleDateFormat(aMask);
 returnValue = df.format(aDate);
 return (returnValue);
 }

 public static int getYear() {
 Calendar c = Calendar.getInstance();
 int yy = c.get(Calendar.YEAR);
 return yy;
 }

 public static int getMonth() {
 Calendar c = Calendar.getInstance();
 int month = c.get(Calendar.MONTH);
 return month+1;
 } 

 public static int getDate() {
 Calendar c = Calendar.getInstance();
 int date = c.get(Calendar.DATE);
 return date;
 }

 public static int getHour() {
 Calendar c = Calendar.getInstance();
 int hour = c.get(Calendar.HOUR_OF_DAY);
 return hour;
 }

 public static int getSecond() {
 Calendar c = Calendar.getInstance();
 int second = c.get(Calendar.SECOND);
 return second;
 }

 public static int getMinute() {
 Calendar c = Calendar.getInstance();
 int minute = c.get(Calendar.MINUTE);
 return minute;
 } 

 public static String getCurDateTime() {
 return getCurDate() + " " + getCurTime();
 }

 public static String getCurDate() {
 String fullDate = getCurYearMonth();
 int temp = getDate();
 if(temp < 10){
 fullDate += "-0" + temp;
 }else{
 fullDate += "-" + temp;
 }
 return fullDate;
 }

 public static String getCurYearMonth() {
 String fullDate = String.valueOf(getYear());
 int temp = getMonth();
 if(temp < 10){
 fullDate += "-0" + temp;
 }else{
 fullDate += "-" + temp;
 }
 return fullDate;
 }

 public static String getCurTime() {
 String time = getCurHourMinute();
 int temp = getSecond();
 if(temp < 10){
 time += ":0" + temp;
 }else{
 time += ":" + temp;
 }
 return time;
 }

 public static String getCurHourMinute() {
 String time;
 int temp = getHour();
 if(temp < 10){
 time = "0" + temp + ":";
 }else{
 time = temp + ":";
 }
 temp = getMinute();
 if(temp < 10){
 time += "0" + temp;
 }else{
 time += temp;
 }
 return time;
 }
 /**
 *
 * @Description: 获取当前时间
 * @param @return
 * @return StringBuffer
 * @throws
 * @author ningpeng
 * @date 2016年1月8日
 */
 public static StringBuffer getNow()
 {
 Date date = new Date();
 Calendar c = new GregorianCalendar();
 c.setTime(date);
 int year = c.get(Calendar.YEAR);
 int month = c.get(Calendar.MONTH)+1;
 int day = c.get(Calendar.DATE);
 int hour = c.get(Calendar.HOUR_OF_DAY);
 int minute = c.get(Calendar.MINUTE);
 int seconds = c.get(Calendar.SECOND);
 StringBuffer buff = new StringBuffer();
 buff.append(year).append(month).append(day).append(hour).append(minute).append(seconds).toString();
 return buff;
 }

 public static String DateFormat(Date date) {
 Calendar c=Calendar.getInstance();
 c.setTime(date);
 c.get(java.util.Calendar.HOUR_OF_DAY);
 String pattern="yyyy-MM-dd";
 if(c.get(java.util.Calendar.HOUR_OF_DAY)!=0){
 pattern="yyyy-MM-dd hh";
 }else if(c.get(java.util.Calendar.MINUTE)!=0){
 pattern="yyyy-MM-dd hh:mm";
 }else if(c.get(java.util.Calendar.SECOND)!=0){
 pattern="yyyy-MM-dd hh:mm:ss";
 }
 return new SimpleDateFormat(pattern).format(date);
 }

 public static void main(String[] args){
 System.out.println(getMonth());
 }
 }