这篇文章主要介绍了Java实现的日期处理类,结合完整实例形式分析了Java针对日期的获取、运算、转换等相关操作技巧,需要的朋友可以参考下
本文实例讲述了Java实现的日期处理类。分享给大家供大家参考，具体如下：
开发中常常要使用日期，先小结如下，以备后用。
import java.text.ParseException;import java.text.SimpleDateFormat;import java.util.Calendar;import java.util.Date;public class FormatTime { private final static SimpleDateFormat sdf=new SimpleDateFormat("yyyyMMdd"); private final static SimpleDateFormat sdfymdhm = new SimpleDateFormat("yyyyMMddHHmmss"); private final static SimpleDateFormat sdfymdhms = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss"); /** * * @Title: getCurrentDay * @Description: TODO 获取当天时间(20161109) * @return */ public static String getCurrentDay(){ return sdf.format(new Date()); } /** * * @Title: fTime2 * @Description: TODO 获取time这个日期以前dayAgo天的日期 * @return */ public static String fTime(String time,int dayAgo){ Date date = null; try { date = sdf.parse(time); } catch (ParseException e) { throw new RuntimeException(e); } Calendar calendar = Calendar.getInstance(); calendar.setTime(date); if(dayAgo>0){ calendar.add(Calendar.DAY_OF_MONTH, -dayAgo);//前15天数据 date = calendar.getTime(); calendar.setTime(date); } int year=calendar.get(Calendar.YEAR); int month=calendar.get(Calendar.MONTH) + 1; int day = calendar.get(Calendar.DAY_OF_MONTH); String mon=""; String d=""; if(month<10){ mon="0"+month; }else{ mon=month+""; } if(day<10){ d="0"+day; }else{ d=""+day; } String ret=year+""+mon+""+d; return ret; } /** * * @Title: fTime2 * @Description: TODO 获取time这个日期以后dayAfter天的日期 * @return */ public static String fTime2(String time,int dayAfter){ Date date = null; try { date = sdf.parse(time); } catch (ParseException e) { throw new RuntimeException(e); } Calendar calendar = Calendar.getInstance(); calendar.setTime(date); if(dayAfter>0){ calendar.add(Calendar.DAY_OF_MONTH, +dayAfter);//后15天数据 date = calendar.getTime(); calendar.setTime(date); } int year=calendar.get(Calendar.YEAR); int month=calendar.get(Calendar.MONTH) + 1; int day = calendar.get(Calendar.DAY_OF_MONTH); String mon=""; String d=""; if(month<10){ mon="0"+month; }else{ mon=month+""; } if(day<10){ d="0"+day; }else{ d=""+day; } String ret=year+""+mon+""+d; return ret; } /** * * @Title: getDefaultTime * @Description: TODO 获取昨天的日期 * @return */ public static String getDefaultTime(){ Calendar calendar = Calendar.getInstance(); calendar.add(Calendar.DAY_OF_MONTH, -1);//前1天 Date date = calendar.getTime(); String time=sdf.format(date); return time; } /** * * @Title: getSunday * @Description: TODO 获取最近一个星期天 * @return */ public static String getSunday(){ SimpleDateFormat f = new SimpleDateFormat("yyyyMMdd"); Calendar c = Calendar.getInstance(); c.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY); return f.format(c.getTime()); } /** * * @Title: getMonthFirstDay * @Description: TODO 获取本月第一天 * @return */ public static String getCurrentMonthFirstDay(){ Calendar cal_1=Calendar.getInstance();//获取当前日期 cal_1.add(Calendar.MONTH, 0); cal_1.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天 String firstDay = sdf.format(cal_1.getTime()); return firstDay; } /** * * @Title: getMonthFirstDay * @Description: TODO 获取上月第一天 * @return */ public static String getPreviousMonthFirstDay(){ //获取当前月第一天： Calendar c = Calendar.getInstance(); c.add(Calendar.MONTH, -1); c.set(Calendar.DAY_OF_MONTH,1);//设置为1号,当前日期既为本月第一天 String first = sdf.format(c.getTime()); return first; } /** * * @Title: getMonthFirstDay * @Description: TODO 获取上月最后一天 * @return */ public static String getPreviousMonthLastDay(){ //获取当前月最后一天 Calendar ca = Calendar.getInstance(); ca.set(Calendar.DAY_OF_MONTH,0);// String lastDay = sdf.format(ca.getTime()); return lastDay; } /** * * @Title: getCurrentMonthLastDay * @Description: TODO 获取指定时间最后一天 * @return */ public static String getCurrentMonthLastDay(String time){ Date date =null; try { date= sdf.parse(time); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } //获取当前月最后一天 Calendar ca = Calendar.getInstance(); ca.setTime(date); ca.set(Calendar.DAY_OF_MONTH, ca.getActualMaximum(Calendar.DAY_OF_MONTH)); // String lastDay = sdf.format(ca.getTime()); return lastDay; } /*** * * @Title: getCurrentWeekDay * @Description: TODO 获取本周周一 */ public static String getCurrentMonday(){ Calendar cal = Calendar.getInstance(); cal.setFirstDayOfWeek(Calendar.MONDAY);//将每周第一天设为星期一，默认是星期天 cal.add(Calendar.DATE, 0); cal.set(Calendar.DAY_OF_WEEK,Calendar.MONDAY); String monday = sdf.format(cal.getTime()); return monday; } /*** * * @Title: getPreviousSunday * @Description: TODO 获取上周周日 */ public static String getPreviousSunday(){ Calendar cal = Calendar.getInstance(); cal.setFirstDayOfWeek(Calendar.MONDAY);//将每周第一天设为星期一，默认是星期天 cal.add(Calendar.DATE, -1*7); cal.set(Calendar.DAY_OF_WEEK, Calendar.SUNDAY); String sunday =sdf.format(cal.getTime()); return sunday; } /** * * @Title: getMiniSencond * @Description: TODO 将日期转换为毫秒数 * @param str * @return */ public static String getMiniSencond(String str){ long millionSeconds=0; try { millionSeconds = sdfymdhm.parse(str).getTime();//毫秒 } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return millionSeconds+""; } /** * * @Title: getDateSencond * @Description: TODO 将日期转换为毫秒数 * @param str * @return */ public static long getDateSencond(String str){ long millionSeconds=0; try { millionSeconds = sdfymdhms.parse(str).getTime();//毫秒 } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return millionSeconds; } /** * 计算日期相差天数 * @param str1 * @param str2 * @return */ public static int getDistanceOfTwoDate(String str1,String str2){ int result=0; try{ Date date1 = sdf.parse(str1); Date date2 =sdf.parse(str2); Calendar aCalendar = Calendar.getInstance(); aCalendar.setTime(date1); int day1 = aCalendar.get(Calendar.DAY_OF_YEAR); aCalendar.setTime(date2); int day2 = aCalendar.get(Calendar.DAY_OF_YEAR); result = day1-day2; }catch(Exception e){ e.printStackTrace(); } return result; } /** * * @Title: long2Date * @Description: TODO long 转日期(年-月-日 时-分-秒) * @param timestamp * @return */ public static String longToDate(Long msecond){ Date date = new Date(msecond); return sdfymdhms.format(date); }}
以上就是Java中日期处理类的实现实例分享的详细内容，更多请关注其它相关文章！
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