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());
}
}