Android時間戳與字符串相互轉換 Calendar

時間戳在開發中用到的非常頻繁，這裏做下筆記，總結下項目裏的遇到的關於時間戳轉換的問題

public class DataUtils {
    private static String mYear; // 當前年
    private static String mMonth; // 月
    private static String mDay;
    private static String mWay;


    /**
     * 獲取當前日期幾月幾號
     */
    public static String getDateString() {


        final Calendar c = Calendar.getInstance();
        c.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
        mMonth = String.valueOf(c.get(Calendar.MONTH) + 1);// 獲取當前月份
        mDay = String.valueOf(c.get(Calendar.DAY_OF_MONTH));// 獲取當前月份的日期號碼
        if(Integer.parseInt(mDay) > MaxDayFromDay_OF_MONTH(Integer.parseInt(mYear),(Integer.parseInt(mMonth)))){
            mDay = String.valueOf(MaxDayFromDay_OF_MONTH(Integer.parseInt(mYear),(Integer.parseInt(mMonth))));
        }
        return mMonth + "月" + mDay + "日";
    }


    /**
     * 獲取當前年月日
     *
     * @return
     */
    public static String StringData() {


        final Calendar c = Calendar.getInstance();
        c.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
        mYear = String.valueOf(c.get(Calendar.YEAR));// 獲取當前年份
        mMonth = String.valueOf(c.get(Calendar.MONTH) + 1);// 獲取當前月份
        mDay = String.valueOf(c.get(Calendar.DAY_OF_MONTH));// 獲取當前月份的日期號碼
        if(Integer.parseInt(mDay) > MaxDayFromDay_OF_MONTH(Integer.parseInt(mYear),(Integer.parseInt(mMonth)))){
            mDay = String.valueOf(MaxDayFromDay_OF_MONTH(Integer.parseInt(mYear),(Integer.parseInt(mMonth))));
        }
        return mYear + "-" + (mMonth.length()==1?"0"+mMonth:mMonth) + "-" + (mDay.length()==1?"0"+mDay:mDay);
    }


    /**
     * 根據當前日期獲得是星期幾
     *
     * @return
     */
    public static String getWeek(String time) {
        String Week = "";


        SimpleDateFormat format = new SimpleDateFormat("yyyy-MM-dd");
        Calendar c = Calendar.getInstance();
        try {


            c.setTime(format.parse(time));


        } catch (ParseException e) {
            e.printStackTrace();
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 1) {
            Week += "周天";
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 2) {
            Week += "週一";
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 3) {
            Week += "週二";
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 4) {
            Week += "週三";
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 5) {
            Week += "週四";
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 6) {
            Week += "週五";
        }
        if (c.get(Calendar.DAY_OF_WEEK) == 7) {
            Week += "週六";
        }
        return Week;
    }


    /**
     * 獲取今天往後一週的日期（幾月幾號）
     */
    public static List<String> getSevendate() {
        List<String> dates = new ArrayList<String>();
        final Calendar c = Calendar.getInstance();
        c.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));


        for (int i = 0; i < 7; i++) {
            mYear = String.valueOf(c.get(Calendar.YEAR));// 獲取當前年份
            mMonth = String.valueOf(c.get(Calendar.MONTH) + 1);// 獲取當前月份
            if (mMonth.length()<2)
                mMonth="0"+ mMonth;
            mDay = String.valueOf(c.get(Calendar.DAY_OF_MONTH) + i);// 獲取當前日份的日期號碼
            if(Integer.parseInt(mDay) > MaxDayFromDay_OF_MONTH(Integer.parseInt(mYear),(i+1))){
                mDay = String.valueOf(MaxDayFromDay_OF_MONTH(Integer.parseInt(mYear),(i+1)));
            }
            String date = mMonth + "-" + mDay ;
            dates.add(date);
        }
        return dates;
    }


    /**
     * 獲取今天往後一週的集合
     */
    public static List<String> get7week() {
        String week = "";
        List<String> weeksList = new ArrayList<String>();
        List<String> dateList = get7date();
        for (String s : dateList) {
            if (s.equals(StringData())) {
                week = "今天";
            } else {
                week = getWeek(s);
            }
            weeksList.add(week);
        }
        return weeksList;
    }


    public static List<String> get7date() {
        List<String> dates = new ArrayList<String>();
        final Calendar c = Calendar.getInstance();
        c.setTimeZone(TimeZone.getTimeZone("GMT+8:00"));
        java.text.SimpleDateFormat sim = new java.text.SimpleDateFormat(
                "yyyy-MM-dd");
        String date = sim.format(c.getTime());
        dates.add(date);
        for (int i = 0; i < 6; i++) {
            c.add(java.util.Calendar.DAY_OF_MONTH, 1);
            date = sim.format(c.getTime());
            dates.add(date);
        }
        return dates;
    }

    /**得到當年當月的最大日期**/
    public static int MaxDayFromDay_OF_MONTH(int year,int month){
        Calendar time=Calendar.getInstance();
        time.clear();
        time.set(Calendar.YEAR,year);
        time.set(Calendar.MONTH,month-1);//注意,Calendar對象默認一月爲0
        int day=time.getActualMaximum(Calendar.DAY_OF_MONTH);//本月份的天數
        return day;
    }
}

Calendar 的 month 從 0 開始，也就是全年 12 個月由 0 ~ 11 進行表示。

而 Calendar.DAY_OF_WEEK 定義和值如下：

Calendar.SUNDAY = 1
Calendar.MONDAY = 2
Calendar.TUESDAY = 3
Calendar.WEDNESDAY = 4
Calendar.THURSDAY = 5
Calendar.FRIDAY = 6
Calendar.SATURDAY = 7

/ 字符串轉換日期格式  
    // DateFormat fmtDateTime = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss");  
    // 接收傳入參數  
    // String strDate = args[1];  
    // 得到日期格式對象  
    // Date date = fmtDateTime.parse(strDate);  
  
    // 完整顯示今天日期時間  
    String str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(new Date());  
    System.out.println(str);  
  
    // 創建 Calendar 對象  
    Calendar calendar = Calendar.getInstance();  
  
    try  
    {  
      // 對 calendar 設置時間的方法  
      // 設置傳入的時間格式  
      SimpleDateFormat dateFormat = new SimpleDateFormat("yyyy-M-d H:m:s");  
      // 指定一個日期  
      Date date = dateFormat.parse("2013-6-1 13:24:16");  
      // 對 calendar 設置爲 date 所定的日期  
      calendar.setTime(date);  
  
      // 按特定格式顯示剛設置的時間  
      str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());  
      System.out.println(str);  
    }  
    catch (ParseException e)  
    {  
      e.printStackTrace();  
    }  
  
    // 或者另一種設置 calendar 方式  
    // 分別爲 year, month, date, hourOfDay, minute, second  
    calendar = Calendar.getInstance();  
    calendar.set(2013, 1, 2, 17, 35, 44);  
    str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());  
    System.out.println(str);  
  
    // Calendar 取得當前時間的方法  
    // 初始化 (重置) Calendar 對象  
    calendar = Calendar.getInstance();  
    // 或者用 Date 來初始化 Calendar 對象  
    calendar.setTime(new Date());  
  
    // setTime 類似上面一行  
    // Date date = new Date();  
    // calendar.setTime(date);  
  
    str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SSS")).format(calendar.getTime());  
    System.out.println(str);  
  
    // 顯示年份  
    int year = calendar.get(Calendar.YEAR);  
    System.out.println("year is = " + String.valueOf(year));  
  
    // 顯示月份 (從0開始, 實際顯示要加一)  
    int month = calendar.get(Calendar.MONTH);  
    System.out.println("nth is = " + (month + 1));  
  
    // 本週幾  
    int week = calendar.get(Calendar.DAY_OF_WEEK);  
    System.out.println("week is = " + week);  
  
    // 今年的第 N 天  
    int DAY_OF_YEAR = calendar.get(Calendar.DAY_OF_YEAR);  
    System.out.println("DAY_OF_YEAR is = " + DAY_OF_YEAR);  
  
    // 本月第 N 天  
    int DAY_OF_MONTH = calendar.get(Calendar.DAY_OF_MONTH);  
    System.out.println("DAY_OF_MONTH = " + String.valueOf(DAY_OF_MONTH));  
  
    // 3小時以後  
    calendar.add(Calendar.HOUR_OF_DAY, 3);  
    int HOUR_OF_DAY = calendar.get(Calendar.HOUR_OF_DAY);  
    System.out.println("HOUR_OF_DAY + 3 = " + HOUR_OF_DAY);  
  
    // 當前分鐘數  
    int MINUTE = calendar.get(Calendar.MINUTE);  
    System.out.println("MINUTE = " + MINUTE);  
  
    // 15 分鐘以後  
    calendar.add(Calendar.MINUTE, 15);  
    MINUTE = calendar.get(Calendar.MINUTE);  
    System.out.println("MINUTE + 15 = " + MINUTE);  
  
    // 30分鐘前  
    calendar.add(Calendar.MINUTE, -30);  
    MINUTE = calendar.get(Calendar.MINUTE);  
    System.out.println("MINUTE - 30 = " + MINUTE);  
  
    // 格式化顯示  
    str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());  
    System.out.println(str);  
  
    // 重置 Calendar 顯示當前時間  
    calendar.setTime(new Date());  
    str = (new SimpleDateFormat("yyyy-MM-dd HH:mm:ss:SS")).format(calendar.getTime());  
    System.out.println(str);  
  
    // 創建一個 Calendar 用於比較時間  
    Calendar calendarNew = Calendar.getInstance();  
  
    // 設定爲 5 小時以前，後者大，顯示 -1  
    calendarNew.add(Calendar.HOUR, -5);  
    System.out.println("時間比較：" + calendarNew.compareTo(calendar));  
  
    // 設定7小時以後，前者大，顯示 1  
    calendarNew.add(Calendar.HOUR, +7);  
    System.out.println("時間比較：" + calendarNew.compareTo(calendar));  
  
    // 退回 2 小時，時間相同，顯示 0  
    calendarNew.add(Calendar.HOUR, -2);  
    System.out.println("時間比較：" + calendarNew.compareTo(calendar));