java擷取時間、擷取日期

 java獲得毫秒 ：System.currentTimeMillis()  java獲得納秒 ：System.nanoTime() (用於擷取很精確的時間，推薦！) java獲得當前日期：    GregorianCalendar date_1=(GregorianCalendar)Calendar.getInstance();    java.sql.Date date_2= new java.sql.Date(date_1.getTime().getTime());  ---------------------------------------------------------------------------------------import java.text.ParseException;  import java.text.SimpleDateFormat;  import java.util.Calendar;  import java.util.Date;        public class DateTest {      public static void main(String[] args) throws ParseException {          Calendar now = Calendar.getInstance();          System.out.println("年: " + now.get(Calendar.YEAR));          System.out.println("月: " + (now.get(Calendar.MONTH) + 1));          System.out.println("日: " + now.get(Calendar.DAY_OF_MONTH));          System.out.println("時: " + now.get(Calendar.HOUR_OF_DAY));          System.out.println("分: " + now.get(Calendar.MINUTE));          System.out.println("秒: " + now.get(Calendar.SECOND));          System.out.println("目前時間毫秒數：" + now.getTimeInMillis());          System.out.println(now.getTime());            Date d = new Date();          System.out.println(d);          SimpleDateFormat sdf = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");          //SimpleDateFormat sdf = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss");         String dateNowStr = sdf.format(d);          System.out.println("格式化後的日期：" + dateNowStr);                    String str = "2012-08-20 17:52:07";  //要跟上面定義的格式一樣          Date today = sdf.parse(str);          System.out.println("字串轉成日期：" + today);      } }  輸出結果：年: 2012月: 8日: 20時: 17分: 53秒: 46目前時間毫秒數：1345456426312Mon Aug 20 17:53:46 CST 2012Mon Aug 20 17:53:46 CST 2012格式化後的日期：2012-08-20 17:53:46字串轉成日期：Mon Aug 20 17:52:07 CST 2012---------------------------------------------------------------------------------------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 {      //用來全域控制 上一周，本周，下一周的周數變化      private  int weeks = 0;      private int MaxDate;//一月最大天數      private int MaxYear;//一年最大天數      public static void main(String[] args) {          TimeTest tt = new TimeTest();          System.out.println("擷取當天日期:"+tt.getNowTime("yyyy-MM-dd"));          System.out.println("擷取本周一日期:"+tt.getMondayOFWeek());          System.out.println("擷取本周日的日期:"+tt.getCurrentWeekday());          System.out.println("擷取上周一日期:"+tt.getPreviousWeekday());          System.out.println("擷取上周日日期:"+tt.getPreviousWeekSunday());          System.out.println("擷取下周一日期:"+tt.getNextMonday());          System.out.println("擷取下周日日期:"+tt.getNextSunday());          System.out.println("獲得相應周的周六的日期:"+tt.getNowTime("yyyy-MM-dd"));          System.out.println("擷取本月第一天日期:"+tt.getFirstDayOfMonth());          System.out.println("擷取本月最後一天日期:"+tt.getDefaultDay());          System.out.println("擷取上月第一天日期:"+tt.getPreviousMonthFirst());          System.out.println("擷取上月最後一天的日期:"+tt.getPreviousMonthEnd());          System.out.println("擷取下月第一天日期:"+tt.getNextMonthFirst());          System.out.println("擷取下月最後一天日期:"+tt.getNextMonthEnd());        System.out.println("擷取本年有多少天:"+tt.getMaxYear());          System.out.println("擷取本年的第一天日期:"+tt.getCurrentYearFirst());          System.out.println("擷取本年最後一天日期:"+tt.getCurrentYearEnd());          System.out.println("擷取去年的第一天日期:"+tt.getPreviousYearFirst());          System.out.println("擷取去年的最後一天日期:"+tt.getPreviousYearEnd());          System.out.println("擷取明年第一天日期:"+tt.getNextYearFirst());          System.out.println("擷取明年最後一天日期:"+tt.getNextYearEnd());          System.out.println("擷取本季度第一天到最後一天:"+tt.getThisSeasonTime(11));          System.out.println("擷取兩個日期之間間隔天數2011-12-1~2012-7.29:"+TimeTest.getTwoDay("2012-7-29","2011-12-1"));      }                  /**         * 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         */      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          */      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         */      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;        }            //擷取當月第一天      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;        }            // 獲得本周星期日的日期        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;      }                  //擷取當天時間       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;      }            // 獲得當前日期與本周日相差的天數      private int getMondayPlus() {          Calendar cd = Calendar.getInstance();          // 獲得今天是一周的第幾天，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;          }      }            //獲得本周一的日期      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;      }          //獲得相應周的周六的日期      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;      }         // 獲得上周星期日的日期      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;      }     // 獲得上周星期一的日期      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;      }            // 獲得下周星期一的日期      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;      }         // 獲得下周星期日的日期      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);//日期復原一天，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);//日期復原一天，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);//日期復原一天，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);//把日期復原一天。          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);//把日期復原一天。          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;                }            /**      * 擷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);    }  }