Android日期工具类DateHelper
一个工具类，可以得到指定月份的天数，可以得到以前或以后多少天、周、月、年的日期等。
yne7
10年前发布
一个工具类，可以得到指定月份的天数，可以得到以前或以后多少天、周、月、年的日期等。
import android.annotation.SuppressLint; import android.text.TextUtils; import java.text.ParseException; import java.text.SimpleDateFormat; import java.util.Calendar; import java.util.Date; @SuppressLint("SimpleDateFormat") public class DateHelper { private static DateHelper util; public static DateHelper getInstance() { if (util == null) { util = new DateHelper(); } return util; } private DateHelper() { super(); } public SimpleDateFormat date_Formater_1 = new SimpleDateFormat( "yyyy-MM-dd HH:mm:ss"); public SimpleDateFormat date_Formater_2 = new SimpleDateFormat("yyyy-MM-dd"); public Date getDate(String dateStr) { Date date = new Date(); if (TextUtils.isEmpty(dateStr)) { return date; } try { date = date_Formater_1.parse(dateStr); return date; } catch (ParseException e) { e.printStackTrace(); } return date; } public String getDataString_1(Date date) { if (date == null) { date = new Date(); } String str = date_Formater_1.format(date); return str; } public String getDataString_2(Date date) { if (date == null) { date = new Date(); } String str = date_Formater_2.format(date); return str; } /** * 将日期变成常见中文格式 * * @param date * @return */ public String getRencentTime(String date) { Date time = getDate(date); if (time == null) { return "一个月前"; } String ftime = ""; Calendar cal = Calendar.getInstance(); String curDate = date_Formater_2.format(cal.getTime()); String paramDate = date_Formater_2.format(time); if (curDate.equals(paramDate)) { int hour = (int) ((cal.getTimeInMillis() - time.getTime()) / 3600000); if (hour == 0) ftime = Math.max( (cal.getTimeInMillis() - time.getTime()) / 60000, 1) + "分钟前"; else ftime = hour + "小时前"; return ftime; } long lt = time.getTime() / 86400000; long ct = cal.getTimeInMillis() / 86400000; int days = (int) (ct - lt); if (days == 0) { int hour = (int) ((cal.getTimeInMillis() - time.getTime()) / 3600000); if (hour == 0) ftime = Math.max( (cal.getTimeInMillis() - time.getTime()) / 60000, 1) + "分钟前"; else ftime = hour + "小时前"; } else if (days == 1) { ftime = "昨天"; } else if (days == 2) { ftime = "前天"; } else if (days > 2 && days <= 10) { ftime = days + "天前"; } else if (days > 10) { ftime = "一个月前"; } else { ftime = date_Formater_2.format(time); } return ftime; } /** * 日期时间格式转换 * * @param typeFrom * 原格式 * @param typeTo * 转为格式 * @param value * 传入的要转换的参数 * @return */ public String stringDateToStringData(String typeFrom, String typeTo, String value) { String re = value; SimpleDateFormat sdfFrom = new SimpleDateFormat(typeFrom); SimpleDateFormat sdfTo = new SimpleDateFormat(typeTo); try { re = sdfTo.format(sdfFrom.parse(re)); } catch (ParseException e) { // TODO Auto-generated catch block e.printStackTrace(); } return re; } /** * 得到这个月有多少天 * * @param year * @param month * @return */ public int getMonthLastDay(int year, int month) { if (month == 0) { return 0; } Calendar a = Calendar.getInstance(); a.set(Calendar.YEAR, year); a.set(Calendar.MONTH, month - 1); a.set(Calendar.DATE, 1);// 把日期设置为当月第一天 a.roll(Calendar.DATE, -1);// 日期回滚一天，也就是最后一天 int maxDate = a.get(Calendar.DATE); return maxDate; } /** * 得到年份 * * @return */ public String getCurrentYear() { Calendar c = Calendar.getInstance(); return c.get(Calendar.YEAR) + ""; } /** * 得到月份 * * @return */ public String getCurrentMonth() { Calendar c = Calendar.getInstance(); return (c.get(Calendar.MONTH) + 1) + ""; } /** * 获得当天的日期 * * @return */ public String getCurrDay() { Calendar c = Calendar.getInstance(); return c.get(Calendar.DAY_OF_MONTH) + ""; } /** * 得到几天/周/月/年后的日期，整数往后推,负数往前移动 * * @param calendar * @param calendarType * Calendar.DATE,Calendar.WEEK_OF_YEAR,Calendar.MONTH,Calendar. * YEAR * @param next * @return */ public String getDayByDate(Calendar calendar, int calendarType, int next) { calendar.add(calendarType, next); Date date = calendar.getTime(); String dateString = date_Formater_1.format(date); return dateString; } } String dataStr = DateHelper.getInstance().getDataString_1(null); String toStringData = DateHelper.getInstance().stringDateToStringData("yyyy-MM-dd HH:mm:ss", "yyyy-MM-dd", dataStr); String date = DateHelper.getInstance().getDayByDate( Calendar.getInstance(), Calendar.DATE, 1); String week = DateHelper.getInstance().getDayByDate( Calendar.getInstance(), Calendar.WEEK_OF_YEAR, 1); String month = DateHelper.getInstance().getDayByDate( Calendar.getInstance(), Calendar.MONTH, 1); String year = DateHelper.getInstance().getDayByDate( Calendar.getInstance(), Calendar.YEAR, 1); int lastDay = DateHelper.getInstance().getMonthLastDay(2015, 2); System.out.println(dataStr); System.out.println(toStringData); System.out.println(date); System.out.println(week); System.out.println(month); System.out.println(year); System.out.println("2月有"+lastDay+"天");