?

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

/**
?* @author dengdahong214
?*
?* TODO 要更改此生成的類型注釋的模板，請轉至 窗口 － 首選項 － Java － 代碼樣式 － 代碼模板
?*/
public class DateUtil {
??? public static final int MILLISECONDS_PER_SECOND = 1000;
??? public static final int MILLISECONDS_PER_DAY = 86400000;
??? public static final int MILLISECONDS_PER_HOUR = 3600000;
??? public static final int MILLISECONDS_PER_MINUTE = 60000;

??? /*
???? * 日期按指定格式轉化成字符串
???? */
??? public static String dateToStr(String aMask,Date date){
??????? SimpleDateFormat df = new SimpleDateFormat(aMask);
??????? String dateAsString = df.format(date);
??????? return dateAsString;
??? }
??? public static String getCurrentTime(){
??????? return getToday("HH:mm:ss");
??? }
??? /*
???? * 按指定格式返回當天日期的字符串形式
???? */
??? public static String getToday(String aMask){
??????? Date today = new Date();
??????? String todayAsString = dateToStr(aMask,today);
??????? return todayAsString;
??? }
??? /*
???? * 按默認格式返回當天日期的字符串形式
???? */
??? public static String getToday(){
??????? return getToday("yyyy-MM-dd");
??? }
??? /*
???? * 把字符串按指定格式轉化成Date
???? */
??? public static Date strToDate(String aMask,String strDate) {
??????? SimpleDateFormat format = new SimpleDateFormat(aMask);
??????? Date date = null;
??????? try {
??????????? date = format.parse(strDate);
??????? } catch (ParseException e) {
??????????? e.printStackTrace();
??????? }
??????? return date;
??? }
??? /*
???? * 把字符串按默認格式轉化成Date
???? */
??? public static Date strToDate(String strDate) {
??????? return strToDate("yyyy-MM-dd",strDate);
??? }
??? /*
???? * 日期相減得到的毫秒數
???? */
??? public static long sub(String aMask,String strBeginDate, String strEndDate) {
??????? long dateRange=0;
??????? int num = 0;
??????? Date beginDate = strToDate(aMask,strBeginDate);
??????? Date endDate = strToDate(aMask,strEndDate);
??????? dateRange = endDate.getTime() - beginDate.getTime();
??????? return dateRange;
??? }
??? /*
???? * 日期相減得到的毫秒數
???? */
??? public static long sub(String strBeginDate, String strEndDate) {
??????? long dateRange=0;
??????? int num = 0;
??????? Date beginDate = strToDate(strBeginDate);
??????? Date endDate = strToDate(strEndDate);
??????? dateRange = endDate.getTime() - beginDate.getTime();
??????? return dateRange;
??? }
??? /*
???? * 日期相減得到的天數
???? */
??? public static String subToDay(String strBeginDate, String strEndDate){
??????? String dayNum = "";
??????? long dateRange = sub(strBeginDate,strEndDate);
??????? dayNum = ""+(dateRange/MILLISECONDS_PER_DAY);
??????? return dayNum;
??? }
??? /*
???? * 日期相減得到的秒數
???? */
??? public static String subToSecond(String aMask,String strBeginDate, String strEndDate){
??????? String secNum = "";
??????? long dateRange = sub(aMask,strBeginDate,strEndDate);
??????? secNum = ""+(dateRange/MILLISECONDS_PER_SECOND);
??????? return secNum;
??? }
??? public static String subToSecond(String strBeginDate, String strEndDate){
??????? String secNum = "";
??????? long dateRange = sub("yyyy-MM-dd HH:mm:ss",strBeginDate,strEndDate);
??????? secNum = ""+(dateRange/MILLISECONDS_PER_SECOND);
??????? return secNum;
??? }
??? public static void main(String[] args) {
??????? System.out.println("按默認格式返回今天日期:"+getToday());
??????? System.out.println("按指定格式返回今天日期:"+getToday("yyyy-MM-dd HH:mm:ss"));
??????? System.out.println("日期相差天數:"+subToDay("2006-08-02 23:02:01", "2006-08-03 01:02:01"));
??????? System.out.println("日期相差秒數:"+subToSecond("2006-08-02 23:02:01", "2006-08-03 01:02:01"));
??????? System.out.println("當前時間:"+getCurrentTime());
??? }
}