日期操作方法讲解与实现
取得指定月份的第一天与取得指定月份的最后一天
/***取得指定月份的第一天**@paramstrdateString*@returnString*/publicStringgetMonthBegin(Stringstrdate){java.util.Datedate=parseFormatDate(strdate);returnformatDateByFormat(date,"yyyy-MM")+"-01";}/***取得指定月份的最后一天**@paramstrdateString*@returnString*/publicStringgetMonthEnd(Stringstrdate){java.util.Datedate=parseFormatDate(getMonthBegin(strdate));Calendarcalendar=Calendar.getInstance();calendar.setTime(date);calendar.add(Calendar.MONTH,1);calendar.add(Calendar.DAY_OF_YEAR,-1);returnformatDate(calendar.getTime());}/***常用的格式化日期**@paramdateDate*@returnString*/publicStringformatDate(java.util.Datedate){returnformatDateByFormat(date,"yyyy-MM-dd");}/***以指定的格式来格式化日期**@paramdateDate*@paramformatString*@returnString*/publicStringformatDateByFormat(java.util.Datedate,Stringformat){Stringresult="";if(date!=null){try{SimpleDateFormatsdf=newSimpleDateFormat(format);result=sdf.format(date);}catch(Exceptionex){LOGGER.info("date:"+date);ex.printStackTrace();}}returnresult;}//—————————————————————packagecom.app.util;/***日期操作**@authorxxx*@version2.0jdk1.4.0tomcat5.1.0*UpdatedDate:2005/03/10*/publicclassDateUtil{/***格式化日期**@paramdateStr*字符型日期*@paramformat*格式*@return返回日期*/publicstaticjava.util.DateparseDate(StringdateStr,Stringformat){java.util.Datedate=null;try{java.text.DateFormatdf=newjava.text.SimpleDateFormat(format);Stringdt=Normal.parse(dateStr).replaceAll("-","/");if((!dt.equals(""))&&(dt.length()<format.length())){dt+=format.substring(dt.length()).replaceAll("[YyMmDdHhSs]","0");}date=(java.util.Date)df.parse(dt);}catch(Exceptione){}returndate;}publicstaticjava.util.DateparseDate(StringdateStr){returnparseDate(dateStr,"yyyy/MM/dd");}publicstaticjava.util.DateparseDate(java.sql.Datedate){returndate;}publicstaticjava.sql.DateparseSqlDate(java.util.Datedate){if(date!=null)returnnewjava.sql.Date(date.getTime());elsereturnnull;}publicstaticjava.sql.DateparseSqlDate(StringdateStr,Stringformat){java.util.Datedate=parseDate(dateStr,format);returnparseSqlDate(date);}publicstaticjava.sql.DateparseSqlDate(StringdateStr){returnparseSqlDate(dateStr,"yyyy/MM/dd");}publicstaticjava.sql.TimestampparseTimestamp(StringdateStr,Stringformat){java.util.Datedate=parseDate(dateStr,format);if(date!=null){longt=date.getTime();returnnewjava.sql.Timestamp(t);}elsereturnnull;}publicstaticjava.sql.TimestampparseTimestamp(StringdateStr){returnparseTimestamp(dateStr,"yyyy/MM/ddHH:mm:ss");}/***格式化输出日期**@paramdate*日期*@paramformat*格式*@return返回字符型日期*/publicstaticStringformat(java.util.Datedate,Stringformat){Stringresult="";try{if(date!=null){java.text.DateFormatdf=newjava.text.SimpleDateFormat(format);result=df.format(date);}}catch(Exceptione){}returnresult;}publicstaticStringformat(java.util.Datedate){returnformat(date,"yyyy/MM/dd");}/***返回年份**@paramdate*日期*@return返回年份*/publicstaticintgetYear(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.get(java.util.Calendar.YEAR);}/***返回月份**@paramdate*日期*@return返回月份*/publicstaticintgetMonth(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.get(java.util.Calendar.MONTH)+1;}/***返回日份**@paramdate*日期*@return返回日份*/publicstaticintgetDay(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.get(java.util.Calendar.DAY_OF_MONTH);}/***返回小时**@paramdate*日期*@return返回小时*/publicstaticintgetHour(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.get(java.util.Calendar.HOUR_OF_DAY);}/***返回分钟**@paramdate*日期*@return返回分钟*/publicstaticintgetMinute(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.get(java.util.Calendar.MINUTE);}/***返回秒钟**@paramdate*日期*@return返回秒钟*/publicstaticintgetSecond(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.get(java.util.Calendar.SECOND);}/***返回毫秒**@paramdate*日期*@return返回毫秒*/publicstaticlonggetMillis(java.util.Datedate){java.util.Calendarc=java.util.Calendar.getInstance();c.setTime(date);returnc.getTimeInMillis();}/***返回字符型日期**@paramdate*日期*@return返回字符型日期*/publicstaticStringgetDate(java.util.Datedate){returnformat(date,"yyyy/MM/dd");}/***返回字符型时间**@paramdate*日期*@return返回字符型时间*/publicstaticStringgetTime(java.util.Datedate){returnformat(date,"HH:mm:ss");}/***返回字符型日期时间**@paramdate*日期*@return返回字符型日期时间*/publicstaticStringgetDateTime(java.util.Datedate){returnformat(date,"yyyy/MM/ddHH:mm:ss");}/***日期相加**@paramdate*日期*@paramday*天数*@return返回相加后的日期*/publicstaticjava.util.DateaddDate(java.util.Datedate,intday){java.util.Calendarc=java.util.Calendar.getInstance();c.setTimeInMillis(getMillis(date)+((long)day)*24*3600*1000);returnc.getTime();}/***日期相减**@paramdate*日期*@paramdate1*日期*@return返回相减后的日期*/publicstaticintdiffDate(java.util.Datedate,java.util.Datedate1){return(int)((getMillis(date)-getMillis(date1))/(24*3600*1000));}}
我来个简单点的,也许有点用敢于奋斗的人，心中不怕困难。
