本來以為有了date4j就萬事無休了，結果在工作的時候發覺有不少腳步僅僅需要兩三個簡單的class執行一下就可以完成任務了。也就是說即使是date4j，相對于這兩三個甚至是一個class來說還是過于臃腫了。于是乎自己寫了個簡單的日期封裝類。
package com.kohri.date;
import java.text.DateFormat;
import java.text.ParseException;
import java.text.SimpleDateFormat;
import java.util.Calendar;
import java.util.Date;
import java.util.GregorianCalendar;
/**
* @descriped a simple class for date
* @author Kohri
* @date 2012/4/22
* @version 1.0
*/public class SimpleDate {
private static String defaultFormat = "yyyy-MM-dd HH:mm:ss";
private static SimpleDateFormat sf =
null ;
private static Calendar cal = Calendar.getInstance();
private static Date date =
null;
/**
* get current date time (default 'yyyy-MM-dd HH:mm:ss')
* @return string
*/ public static String getDateNow() {
sf =
new SimpleDateFormat(defaultFormat);
String currentTime = "";
currentTime = sf.format(
new Date());
return currentTime;
}
/**
* get year (default now)
* @return int
*/ public static int getYear(){
int currentYear = cal.get(Calendar.YEAR);
return currentYear;
}
/**
* get mon (default now)
* @return int
*/ public static int getMonth(){
int currentMonth = cal.get(Calendar.MONTH) + 1;
return currentMonth;
}
/**
* get day of month (default now)
* @return int
*/ public static int getDay(){
int currentDayOfMonth = cal.get(Calendar.DAY_OF_MONTH);
return currentDayOfMonth;
}
/**
* get hours (default now)
* @return int
*/ public static int getHours(){
int currentHours = cal.get(Calendar.HOUR_OF_DAY);
return currentHours;
}
/**
* get minutes (default now)
* @return int
*/ public static int getMinutes(){
int currentMinute = cal.get(Calendar.MINUTE);
return currentMinute;
}
/**
* get seconds (default now)
* @return int
*/ public static int getSeconds(){
int currentSecond = cal.get(Calendar.SECOND);
return currentSecond;
}
/**
* string change to date
* @param strDate
* @param dateFormat
* @return date
*/ public static Date toDate(String strDate, String dateFormat){
if(strDate ==
null || strDate.length() == 0){
return null;
}
Date date =
null;
DateFormat df =
new SimpleDateFormat(dateFormat);
try {
date = df.parse(strDate);
}
catch (ParseException e) {
e.printStackTrace();
}
return date;
}
/**
* Returns this Calendar's time value in milliseconds
* @param p_date
* @return long
*/ public static long getMillisOfDate(Date date) {
cal.setTime(date);
return cal.getTimeInMillis();
}
/**
* compare two date
* return the greater date
* if equals return null
* @param strStartDate
* @param strEndDate
* @return date
*/ public static Date getGreaterDate(String strStartDate, String strEndDate){
Date date =
null;
Date startDate = toDate(strStartDate, "yyyy-MM-dd");
Date endDate = toDate(strEndDate, "yyyy-MM-dd");
long startTime = getMillisOfDate(startDate);
long endTime = getMillisOfDate(endDate);
if((startTime - endTime) > 0){
return startDate;
}
else if((endTime - startTime) > 0){
return endDate;
}
return date;
}
/**
* get days between 2 different date
* @param strStartDate less date (yyyy-MM-dd)
* @param strEndDate greater date (yyyy-MM-dd)
* @return long
*/ public static long getDaysOftwoDiffDate(String strStartDate, String strEndDate){
Date startDate = toDate(strStartDate, "yyyy-MM-dd");
Date endDate = toDate(strEndDate, "yyyy-MM-dd");
long startTime = getMillisOfDate(startDate);
long endTime = getMillisOfDate(endDate);
long betweenDays = (
long) ((endTime - startTime) / ( 1000 * 60 * 60 * 24 ));
return betweenDays;
}
/**
* get weeks between 2 different date
* @param strStartDate less date (yyyy-MM-dd)
* @param strEndDate greater date (yyyy-MM-dd)
* @return long
*/ public static long getWeeksOfTwoDiffDate(String strStartDate, String strEndDate){
return getDaysOftwoDiffDate(strStartDate, strEndDate) / 7;
}
/**
* get months between 2 different date
* @param strStartDate less date (yyyy-MM-dd)
* @param strEndDate greater date (yyyy-MM-dd)
* @return long
*/ public static long getMonthsOfTwoDiffDate(String strStartDate, String strEndDate){
return getDaysOftwoDiffDate(strStartDate, strEndDate) / 30;
}
/**
* get years between 2 different date
* @param strStartDate less date (yyyy-MM-dd)
* @param strEndDate greater date (yyyy-MM-dd)
* @return long
*/ public static long getYearsOfTwoDiffDate(String strStartDate, String strEndDate){
return getDaysOftwoDiffDate(strStartDate, strEndDate) / 365;
}
/**
* add date
* @param date
* @param count
* @param field Calendar.YEAR(MONTH
..)
* @param format DateFormat(yyyy-MM-dd)
* @return string
*/ public static String addDate(Date date,
int count,
int field,String format){
cal.setTime(date);
int year = getYear();
int month = getMonth() - 1;
int day = getDay();
int hours = getHours();
int minutes = getMinutes();
int seconds = getSeconds();
Calendar calendar =
new GregorianCalendar(year, month, day, hours, minutes, seconds);
calendar.add(field,count);
DateFormat df =
new SimpleDateFormat(format);
String tmpDate = df.format(calendar.getTime());
if(date == null){
cal.setTime(new Date());
}else{
cal.setTime(date);
}
return tmpDate;
}
/**
* calendar settime
* @param date
*/ private static void setCalTime(Date date){
if(date !=
null){
cal.setTime(date);
}
}
//setter getter
public static String getDefaultFormat() {
return defaultFormat;
}
public static void setDefaultFormat(String defaultFormat) {
SimpleDate.defaultFormat = defaultFormat;
}
public static Date getDate() {
return date;
}
public static void setDate(Date date) {
SimpleDate.date = date;
setCalTime(date);
}
}