import java.text.DateFormat;   
    import java.text.ParsePosition;   
    import java.text.SimpleDateFormat;   
    import java.util.Calendar;   
    import java.util.Date;   
    import java.util.GregorianCalendar;   
      
    public class TimeTest {   
        //用來全域性控制 上一週，本週，下一週的週數變化   
        private  int weeks = 0;   
        private int MaxDate;//一月最大天數   
        private int MaxYear;//一年最大天數   
           
           
        /**  
         * @param args  
         */  
        public static void main(String[] args) {   
            TimeTest tt = new TimeTest();   
            System.out.println("獲取當天日期:"+tt.getNowTime("yyyy-MM-dd"));   
            System.out.println("獲取本週一日期:"+tt.getMondayOFWeek());   
            System.out.println("獲取本週日的日期~:"+tt.getCurrentWeekday());   
            System.out.println("獲取上週一日期:"+tt.getPreviousWeekday());   
            System.out.println("獲取上週日日期:"+tt.getPreviousWeekSunday());   
            System.out.println("獲取下週一日期:"+tt.getNextMonday());   
            System.out.println("獲取下週日日期:"+tt.getNextSunday());   
            System.out.println("獲得相應周的週六的日期:"+tt.getNowTime("yyyy-MM-dd"));   
            System.out.println("獲取本月第一天日期:"+tt.getFirstDayOfMonth());   
            System.out.println("獲取本月最後一天日期:"+tt.getDefaultDay());   
            System.out.println("獲取上月第一天日期:"+tt.getPreviousMonthFirst());   
            System.out.println("獲取上月最後一天的日期:"+tt.getPreviousMonthEnd());   
            System.out.println("獲取下月第一天日期:"+tt.getNextMonthFirst());   
            System.out.println("獲取下月最後一天日期:"+tt.getNextMonthEnd());   
            System.out.println("獲取本年的第一天日期:"+tt.getCurrentYearFirst());   
            System.out.println("獲取本年最後一天日期:"+tt.getCurrentYearEnd());   
            System.out.println("獲取去年的第一天日期:"+tt.getPreviousYearFirst());   
            System.out.println("獲取去年的最後一天日期:"+tt.getPreviousYearEnd());   
            System.out.println("獲取明年第一天日期:"+tt.getNextYearFirst());   
            System.out.println("獲取明年最後一天日期:"+tt.getNextYearEnd());   
            System.out.println("獲取本季度第一天到最後一天:"+tt.getThisSeasonTime(11));   
            System.out.println("獲取兩個日期之間間隔天數2008-12-1~2008-9.29:"+TimeTest.getTwoDay("2008-12-1","2008-9-29"));   
        }   
           
           
        /**  
            * 得到二個日期間的間隔天數  
            */  
        public static String getTwoDay(String sj1, String sj2) {   
            SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");   
            long day = 0;   
            try {   
             java.util.Date date = myFormatter.parse(sj1);   
             java.util.Date mydate = myFormatter.parse(sj2);   
             day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);   
            } catch (Exception e) {   
             return "";   
            }   
            return day + "";   
        }   
      
      
        /**  
            * 根據一個日期，返回是星期幾的字串  
            *   
            * @param sdate  
            * @return  
            */  
        public static String getWeek(String sdate) {   
            // 再轉換為時間   
            Date date = TimeTest.strToDate(sdate);   
            Calendar c = Calendar.getInstance();   
            c.setTime(date);   
            // int hour=c.get(Calendar.DAY_OF_WEEK);   
            // hour中存的就是星期幾了，其範圍 1~7   
            // 1=星期日 7=星期六，其他類推   
            return new SimpleDateFormat("EEEE").format(c.getTime());   
        }   
      
        /**  
            * 將短時間格式字串轉換為時間 yyyy-MM-dd   
            *   
            * @param strDate  
            * @return  
            */  
        public static Date strToDate(String strDate) {   
            SimpleDateFormat formatter = new SimpleDateFormat("yyyy-MM-dd");   
            ParsePosition pos = new ParsePosition(0);   
            Date strtodate = formatter.parse(strDate, pos);   
            return strtodate;   
        }   
      
        /**  
            * 兩個時間之間的天數  
            *   
            * @param date1  
            * @param date2  
            * @return  
            */  
        public static long getDays(String date1, String date2) {   
            if (date1 == null || date1.equals(""))   
             return 0;   
            if (date2 == null || date2.equals(""))   
             return 0;   
            // 轉換為標準時間   
            SimpleDateFormat myFormatter = new SimpleDateFormat("yyyy-MM-dd");   
            java.util.Date date = null;   
            java.util.Date mydate = null;   
            try {   
             date = myFormatter.parse(date1);   
             mydate = myFormatter.parse(date2);   
            } catch (Exception e) {   
            }   
            long day = (date.getTime() - mydate.getTime()) / (24 * 60 * 60 * 1000);   
            return day;   
        }   
      
      
      
           
        // 計算當月最後一天,返回字串   
        public String getDefaultDay(){     
           String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
           Calendar lastDate = Calendar.getInstance();   
           lastDate.set(Calendar.DATE,1);//設為當前月的1號   
           lastDate.add(Calendar.MONTH,1);//加一個月，變為下月的1號   
           lastDate.add(Calendar.DATE,-1);//減去一天，變為當月最後一天   
              
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
        // 上月第一天   
        public String getPreviousMonthFirst(){     
           String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
           Calendar lastDate = Calendar.getInstance();   
           lastDate.set(Calendar.DATE,1);//設為當前月的1號   
           lastDate.add(Calendar.MONTH,-1);//減一個月，變為下月的1號   
           //lastDate.add(Calendar.DATE,-1);//減去一天，變為當月最後一天   
              
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
        //獲取當月第一天   
        public String getFirstDayOfMonth(){     
           String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
           Calendar lastDate = Calendar.getInstance();   
           lastDate.set(Calendar.DATE,1);//設為當前月的1號   
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
        // 獲得本週星期日的日期     
        public String getCurrentWeekday() {   
            weeks = 0;   
            int mondayPlus = this.getMondayPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE, mondayPlus+6);   
            Date monday = currentDate.getTime();   
               
            DateFormat df = DateFormat.getDateInstance();   
            String preMonday = df.format(monday);   
            return preMonday;   
        }   
           
           
        //獲取當天時間    
        public String getNowTime(String dateformat){   
            Date   now   =   new   Date();      
            SimpleDateFormat   dateFormat   =   new   SimpleDateFormat(dateformat);//可以方便地修改日期格式      
            String  hehe  = dateFormat.format(now);      
            return hehe;   
        }   
           
        // 獲得當前日期與本週日相差的天數   
        private int getMondayPlus() {   
            Calendar cd = Calendar.getInstance();   
            // 獲得今天是一週的第幾天，星期日是第一天，星期二是第二天......   
            int dayOfWeek = cd.get(Calendar.DAY_OF_WEEK)-1;         //因為按中國禮拜一作為第一天所以這裡減1   
            if (dayOfWeek == 1) {   
                return 0;   
            } else {   
                return 1 - dayOfWeek;   
            }   
        }   
           
        //獲得本週一的日期   
        public String getMondayOFWeek(){   
             weeks = 0;   
             int mondayPlus = this.getMondayPlus();   
             GregorianCalendar currentDate = new GregorianCalendar();   
             currentDate.add(GregorianCalendar.DATE, mondayPlus);   
             Date monday = currentDate.getTime();   
                
             DateFormat df = DateFormat.getDateInstance();   
             String preMonday = df.format(monday);   
             return preMonday;   
        }   
           
      //獲得相應周的週六的日期   
        public String getSaturday() {   
            int mondayPlus = this.getMondayPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks + 6);   
            Date monday = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preMonday = df.format(monday);   
            return preMonday;   
        }   
           
     // 獲得上週星期日的日期   
        public String getPreviousWeekSunday() {   
            weeks=0;   
            weeks--;   
            int mondayPlus = this.getMondayPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE, mondayPlus+weeks);   
            Date monday = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preMonday = df.format(monday);   
            return preMonday;   
        }   
      
     // 獲得上週星期一的日期   
        public String getPreviousWeekday() {   
            weeks--;   
            int mondayPlus = this.getMondayPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7 * weeks);   
            Date monday = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preMonday = df.format(monday);   
            return preMonday;   
        }   
           
        // 獲得下週星期一的日期   
        public String getNextMonday() {   
            weeks++;   
            int mondayPlus = this.getMondayPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7);   
            Date monday = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preMonday = df.format(monday);   
            return preMonday;   
        }   
           
     // 獲得下週星期日的日期   
        public String getNextSunday() {   
               
            int mondayPlus = this.getMondayPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE, mondayPlus + 7+6);   
            Date monday = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preMonday = df.format(monday);   
            return preMonday;   
        }   
           
           
           
        private int getMonthPlus(){   
            Calendar cd = Calendar.getInstance();   
            int monthOfNumber = cd.get(Calendar.DAY_OF_MONTH);   
            cd.set(Calendar.DATE, 1);//把日期設定為當月第一天    
            cd.roll(Calendar.DATE, -1);//日期回滾一天，也就是最後一天    
            MaxDate=cd.get(Calendar.DATE);    
            if(monthOfNumber == 1){   
                return -MaxDate;   
            }else{   
                return 1-monthOfNumber;   
            }   
        }   
           
      //獲得上月最後一天的日期   
        public String getPreviousMonthEnd(){   
            String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
           Calendar lastDate = Calendar.getInstance();   
          lastDate.add(Calendar.MONTH,-1);//減一個月   
          lastDate.set(Calendar.DATE, 1);//把日期設定為當月第一天    
          lastDate.roll(Calendar.DATE, -1);//日期回滾一天，也就是本月最後一天    
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
      //獲得下個月第一天的日期   
        public String getNextMonthFirst(){   
            String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
           Calendar lastDate = Calendar.getInstance();   
          lastDate.add(Calendar.MONTH,1);//減一個月   
          lastDate.set(Calendar.DATE, 1);//把日期設定為當月第一天    
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
      //獲得下個月最後一天的日期   
        public String getNextMonthEnd(){   
            String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
           Calendar lastDate = Calendar.getInstance();   
          lastDate.add(Calendar.MONTH,1);//加一個月   
          lastDate.set(Calendar.DATE, 1);//把日期設定為當月第一天    
          lastDate.roll(Calendar.DATE, -1);//日期回滾一天，也就是本月最後一天    
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
        //獲得明年最後一天的日期   
        public String getNextYearEnd(){   
            String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
          Calendar lastDate = Calendar.getInstance();   
          lastDate.add(Calendar.YEAR,1);//加一個年   
          lastDate.set(Calendar.DAY_OF_YEAR, 1);   
         lastDate.roll(Calendar.DAY_OF_YEAR, -1);   
           str=sdf.format(lastDate.getTime());   
           return str;     
        }   
           
      //獲得明年第一天的日期   
        public String getNextYearFirst(){   
            String str = "";   
           SimpleDateFormat sdf=new SimpleDateFormat("yyyy-MM-dd");       
      
          Calendar lastDate = Calendar.getInstance();   
          lastDate.add(Calendar.YEAR,1);//加一個年   
          lastDate.set(Calendar.DAY_OF_YEAR, 1);   
               str=sdf.format(lastDate.getTime());   
          return str;     
               
        }   
           
      //獲得本年有多少天   
        private int getMaxYear(){   
            Calendar cd = Calendar.getInstance();   
            cd.set(Calendar.DAY_OF_YEAR,1);//把日期設為當年第一天   
            cd.roll(Calendar.DAY_OF_YEAR,-1);//把日期回滾一天。   
            int MaxYear = cd.get(Calendar.DAY_OF_YEAR);    
            return MaxYear;   
        }   
           
        private int getYearPlus(){   
            Calendar cd = Calendar.getInstance();   
            int yearOfNumber = cd.get(Calendar.DAY_OF_YEAR);//獲得當天是一年中的第幾天   
            cd.set(Calendar.DAY_OF_YEAR,1);//把日期設為當年第一天   
            cd.roll(Calendar.DAY_OF_YEAR,-1);//把日期回滾一天。   
            int MaxYear = cd.get(Calendar.DAY_OF_YEAR);   
            if(yearOfNumber == 1){   
                return -MaxYear;   
            }else{   
                return 1-yearOfNumber;   
            }   
        }   
      //獲得本年第一天的日期   
        public String getCurrentYearFirst(){   
            int yearPlus = this.getYearPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE,yearPlus);   
            Date yearDay = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preYearDay = df.format(yearDay);   
            return preYearDay;   
        }   
           
           
      //獲得本年最後一天的日期 *   
        public String getCurrentYearEnd(){   
            Date date = new Date();   
            SimpleDateFormat   dateFormat   =   new   SimpleDateFormat("yyyy");//可以方便地修改日期格式      
            String  years  = dateFormat.format(date);      
            return years+"-12-31";   
        }   
           
           
      //獲得上年第一天的日期 *   
        public String getPreviousYearFirst(){   
            Date date = new Date();   
            SimpleDateFormat   dateFormat   =   new   SimpleDateFormat("yyyy");//可以方便地修改日期格式      
            String  years  = dateFormat.format(date); int years_value = Integer.parseInt(years);     
            years_value--;   
            return years_value+"-1-1";   
        }   
           
      //獲得上年最後一天的日期   
        public String getPreviousYearEnd(){   
            weeks--;   
            int yearPlus = this.getYearPlus();   
            GregorianCalendar currentDate = new GregorianCalendar();   
            currentDate.add(GregorianCalendar.DATE,yearPlus+MaxYear*weeks+(MaxYear-1));   
            Date yearDay = currentDate.getTime();   
            DateFormat df = DateFormat.getDateInstance();   
            String preYearDay = df.format(yearDay);   
            getThisSeasonTime(11);   
            return preYearDay;   
        }   
           
      //獲得本季度   
        public String getThisSeasonTime(int month){   
            int array[][] = {{1,2,3},{4,5,6},{7,8,9},{10,11,12}};   
            int season = 1;   
            if(month>=1&&month<=3){   
                season = 1;   
            }   
            if(month>=4&&month<=6){   
                season = 2;   
            }   
            if(month>=7&&month<=9){   
                season = 3;   
            }   
            if(month>=10&&month<=12){   
                season = 4;   
            }   
            int start_month = array[season-1][0];   
            int end_month = array[season-1][2];   
               
            Date date = new Date();   
            SimpleDateFormat   dateFormat   =   new   SimpleDateFormat("yyyy");//可以方便地修改日期格式      
            String  years  = dateFormat.format(date);      
            int years_value = Integer.parseInt(years);   
               
            int start_days =1;//years+"-"+String.valueOf(start_month)+"-1";//getLastDayOfMonth(years_value,start_month);   
            int end_days = getLastDayOfMonth(years_value,end_month);   
            String seasonDate = years_value+"-"+start_month+"-"+start_days+";"+years_value+"-"+end_month+"-"+end_days;   
            return seasonDate;   
               
        }   
           
        /**  
         * 獲取某年某月的最後一天  
         * @param year 年  
         * @param month 月  
         * @return 最後一天  
         */  
       private int getLastDayOfMonth(int year, int month) {   
             if (month == 1 || month == 3 || month == 5 || month == 7 || month == 8  
                       || month == 10 || month == 12) {   
                   return 31;   
             }   
             if (month == 4 || month == 6 || month == 9 || month == 11) {   
                   return 30;   
             }   
             if (month == 2) {   
                   if (isLeapYear(year)) {   
                       return 29;   
                   } else {   
                       return 28;   
                   }   
             }   
             return 0;   
       }   
       /**  
        * 是否閏年  
        * @param year 年  
        * @return   
        */  
      public boolean isLeapYear(int year) {   
            return (year % 4 == 0 && year % 100 != 0) || (year % 400 == 0);   
      }   
    }  

l另外的一種方法

    /**  
         * 獲取系統時間  
         * @return  
         */  
        public String getDate(){   
               
             Calendar ca = Calendar.getInstance();   
              int year = ca.get(Calendar.YEAR);//獲取年份   
              int month=ca.get(Calendar.MONTH);//獲取月份    
              int day=ca.get(Calendar.DATE);//獲取日   
              int minute=ca.get(Calendar.MINUTE);//分    
              int hour=ca.get(Calendar.HOUR);//小時    
              int second=ca.get(Calendar.SECOND);//秒   
                 
              String date = year + "年" + (month + 1 )+ "月" + day + "日"+ hour + "時" + minute + "分" + second + "秒";   
      
      
              return date;   
               
        }