Android開發中常用到的一些工具類整理

在開發過程中我們為了代碼簡單重用，常常會對經常用的方法進行一下簡單封裝，方便下次使用。下面就分享一下開發中常用的一些工具類的整理。

時間工具類

/**
   * 日期操作的工具類
*/
public class DateUtil {
   private DateUtil(){
   }
/**
 * 初始化一些時間設置格式
 */
public static final SimpleDateFormat FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss", Locale.CHINA);
public static final SimpleDateFormat FORMAT_DATE = new SimpleDateFormat("yyyy-MM-dd",Locale.CHINA);
public static final SimpleDateFormat FORMAT_TIME = new SimpleDateFormat("HH:mm",Locale.CHINA);

private static final Calendar INSTANCE = Calendar.getInstance();
public static int getYear(){
    return INSTANCE.get(Calendar.YEAR);
}
public static int getMonth(){
    return INSTANCE.get(Calendar.MONTH);
}
public static int getDay(){
    return INSTANCE.get(Calendar.DAY_OF_MONTH);
}
public static int getHours(){
    return INSTANCE.get(Calendar.HOUR_OF_DAY);
}
public static int getMinutes(){
    return INSTANCE.get(Calendar.MINUTE);
}
public static int getSeconds(){
    return INSTANCE.get(Calendar.SECOND);
}

/**
 * 獲取N天前、N天後的 日期
 *
 * @param nowDate
 *            當前日期;
 * @param dayAddNum
 *            正數：N天前，負數：N天後;
 * @return
 */
public static Date getAddDay(Date nowDate, int dayAddNum) {
    Calendar tday = new GregorianCalendar();
    tday.setTime(nowDate);
    tday.add(Calendar.DAY_OF_MONTH, dayAddNum);
    Date preDate = tday.getTime();
    return preDate;
}
/**
 * 獲取N天前、N天後的 日期
 * @param nowDate  當前時間戳;
 * @param dayAddNum 正數：N天前，負數：N天後;
 * @return
 */
public static Date getAddDay(long nowDate, int dayAddNum){
    return getAddDay(new Date(nowDate), dayAddNum);
}

/**
 * 時間格式化
 * @param format
 * @param time
 * @return
 */
public static String formatDate(String format,Long time) {
    return formatDate(new SimpleDateFormat(format, Locale.CHINA), time);
}
/**
 * 時間格式化
 * @param format
 * @param time
 * @return
 */
public static String formatDate(SimpleDateFormat format,Long time) {
    if(null==time || time<=0) return "";
    return format.format(new Date(String.valueOf(time).length() == 13 ? time : time * 1000));
}

/**
 * 將秒轉換為（ 分：秒 格式）
 * @param time 單位：秒
 * @return
 */
public static String getTimeFromInt(int time) {
    if (time <= 0) return "00:00";
    int secondnd = time / 60;
    int million = time % 60;
    String f = secondnd >= 10 ? String.valueOf(secondnd) : "0" + String.valueOf(secondnd);
    String m = million >= 10 ? String.valueOf(million) : "0" + String.valueOf(million);
    return f + ":" + m;
}

/**
 * 根據月份獲得最大天數
 * @param year 年
 * @param month 月
 * @return 最大天數
 */
public static int getMaxDayByMonth(int year,int month){
    Calendar time=Calendar.getInstance();//使用默認時區和語言環境獲得一個日歷
    //注意：在使用set方法之前，必須先調用clear（），否則很多信息會繼承自系統當前的時間
    time.clear();
    time.set(Calendar.YEAR,year);
    time.set(Calendar.MONTH,month);//注意Calendar對象默認一月是為零的
    int day=time.getActualMaximum(Calendar.DAY_OF_MONTH);//獲得本月份的天數
    return day;
}

/**
 * 根據日期獲得星期
 */
public static String getWeek(Date d) {
    final String dayNames[] = { "星期日", "星期一", "星期二", "星期三", "星期四", "星期五","星期六" };
    Calendar calendar = Calendar.getInstance();
    calendar.setTime(d);
    int dayOfWeek = calendar.get(Calendar.DAY_OF_WEEK) - 1;
    if (dayOfWeek < 0)
        dayOfWeek = 0;
    return (dayNames[dayOfWeek]);
}

/**
 * 時間格式化（剛剛、幾分鐘前、幾小時前、昨天、前天、年-月-日）
 * @param time
 * @return
 */
public static String getShortTime(long time) {
    String shortstring = "";
    if (time == 0)
        return shortstring;

    long now = Calendar.getInstance().getTimeInMillis();
    long datetime = (now - time) / 1000;
    if (datetime > 365 * 24 * 60 * 60) {
        shortstring = FORMAT_DATE.format(new Date(time));
    } else if (datetime > 24 * 60 * 60 && ((int) (datetime / (24 * 60 * 60)))==2){
        shortstring = "前天";
    } else if (datetime > 24 * 60 * 60 && ((int) (datetime / (24 * 60 * 60)))==1){
        shortstring = "昨天";
    } else if (datetime > 60 * 60) {
        shortstring = (int) (datetime / (60 * 60)) + "小時前";
    } else if (datetime > 60) {
        shortstring = (int) (datetime / (60)) + "分鐘前";
    } else {
        shortstring = "剛剛";
    }
    return shortstring;
}
/**
 * 時間格式化(秒，分，小時，天)
 * @param time
 * @return
 */
public static String getShortTime2(long time) {
    String shortstring = "";
    if (time == 0)
        return shortstring;

    long now = Calendar.getInstance().getTimeInMillis();
    long datetime = (now - time) / 1000; // 秒
    if (datetime > 24 * 60 * 60) {
        shortstring = (int) (datetime / (24 * 60 * 60)) + "天";
    } else if (datetime > 60 * 60) {
        shortstring = (int) (datetime / (60 * 60)) + "小時";
    } else if (datetime > 60) {
        shortstring = (int) (datetime / (60)) + "分鐘";
    } else {
        shortstring = (int) datetime + "秒";
    }
    return shortstring;
}
/**
 * 獲取當前日期上一周的開始日期 （周日）
 */
public static String previousWeekByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month - 1, day);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    if (1 == dayWeek) {
        cal.add(Calendar.DAY_OF_MONTH, -1);
    }
    cal.setFirstDayOfWeek(Calendar.SUNDAY);//設置一個星期的第一天，按中國的習慣一個星期的第一天是星期一
    int s = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - s);//根據日歷的規則，給當前日期減往星期幾與一個星期第一天的差值
    cal.add(Calendar.WEEK_OF_YEAR, -1);
    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
}
/**
 * 獲取當前日期上一周的結束日期 （周六）
 */
public static String previousWeekEndDayByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month - 1, day);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    if (1 == dayWeek) {
        cal.add(Calendar.DAY_OF_MONTH, -1);
    }
    cal.setFirstDayOfWeek(Calendar.SUNDAY);//設置一個星期的第一天，按中國的習慣一個星期的第一天是星期一
    int s = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    cal.add(Calendar.DATE, cal.getFirstDayOfWeek() + (6 - s));
    cal.add(Calendar.WEEK_OF_YEAR, -1);
    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
}
/**
 * 獲取當前日期當前一周的開始日期 （周日）
 */
public static String getCurrentWeekFirstDayByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month - 1, day);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    if (1 == dayWeek) {
        cal.add(Calendar.DAY_OF_MONTH, -1);
    }
    cal.setFirstDayOfWeek(Calendar.SUNDAY);//設置一個星期的第一天，按中國的習慣一個星期的第一天是星期一
    int s = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    cal.add(Calendar.DATE, cal.getFirstDayOfWeek() - s);//根據日歷的規則，給當前日期減往星期幾與一個星期第一天的差值

    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
}
/**
 * 獲取當前日期當前一周的結束日期 （周六）
 */
public static String getCurrentWeekEndDayByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month - 1, day);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    int dayWeek = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    if (1 == dayWeek) {
        cal.add(Calendar.DAY_OF_MONTH, -1);
    }
    cal.setFirstDayOfWeek(Calendar.SUNDAY);//設置一個星期的第一天，按中國的習慣一個星期的第一天是星期一
    int s = cal.get(Calendar.DAY_OF_WEEK);//獲得當前日期是一個星期的第幾天
    cal.add(Calendar.DATE, cal.getFirstDayOfWeek() + (6 - s));

    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
}
/**
 * 返回上一個月的第一天
 *
 * @return 20120201
 */
public static String previousMonthByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month - 2, 1);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
}
/**
 * 返回下一個月的第一天
 *
 * @return 20120401
 */
public static String nextMonthByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month, 1);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
}
/**
 * 返回當前月的第一天
 *
 * @return 20120101
 */
public static String getCurrentMonthFirstDayByDate(String date) {
    int year = Integer.parseInt(date.substring(0, 4));
    int month = Integer.parseInt(date.substring(4, 6));
    int day = Integer.parseInt(date.substring(6));
    Calendar calendar = Calendar.getInstance();
    calendar.set(year, month - 1, 1);
    Date newdate = calendar.getTime();
    SimpleDateFormat sdf = new SimpleDateFormat("yyyyMMdd");
    Calendar cal = Calendar.getInstance();
    cal.setTime(newdate);
    String imptimeBegin = sdf.format(cal.getTime());
    return imptimeBegin;
  }
}