Android开发记录19-朋友圈动态发布时间计算

calendar.getTimeInMillis()

// 获取去年的年份
	public static int getLastYear() {
		Calendar c = Calendar.getInstance();
		c.add(Calendar.YEAR, -1);
		return c.get(Calendar.YEAR);
	}
	
	// 获取下一年年份
	public static int getNextYear() {
		Calendar c = Calendar.getInstance();
		c.add(Calendar.YEAR, 1);
		return c.get(Calendar.YEAR);
	}

// 获取上一个月的月份
	public static int getLastMonth() {
		Calendar c = Calendar.getInstance();
		c.add(Calendar.MONTH, -1);
		return c.get(Calendar.MONTH) + 1;
	}
	
	// 获取下一个月的月份
	public static int getNextMonth() {
		Calendar c = Calendar.getInstance();
		c.add(Calendar.MONTH, 1);
		return c.get(Calendar.MONTH) + 1;
	}

	private static SimpleDateFormat DATE_FORMAT_TILL_SECOND = new SimpleDateFormat(
			"yyyy-MM-dd HH:mm:ss");

/**
	 * 日期字符串转换为Date
	 * @param dateStr
	 * @param format
	 * @return
	 */
	public static Date strToDate(String dateStr, String format) {
		Date date = null;

		if (!TextUtils.isEmpty(dateStr)) {
			DateFormat df = new SimpleDateFormat(format);
			try {
				date = df.parse(dateStr);
			} catch (ParseException e) {
				e.printStackTrace();
			}
		}
		return date;
	}
	

/**
	 * 日期转换为字符串
	 * @param timeStr
	 * @param format
	 * @return
	 */
	public static String dateToString(String timeStr, String format) {
		// 判断是否是今年
		Date date = DateHelper.strToDate(timeStr, format);
		Calendar calendar = Calendar.getInstance();
		calendar.setTime(date);
		// 如果是今年的话，才去“xx月xx日”日期格式
		if (calendar.get(Calendar.YEAR) == getYear()) {
			return DATE_FORMAT_TILL_DAY_CURRENT_YEAR.format(date);
		}
		
		return DATE_FORMAT_TILL_DAY_CH.format(date);
	}

/**
	 * 日期逻辑
	 * @param dateStr 日期字符串
	 * @return
	 */
	public static String timeLogic(String dateStr) {
		Calendar calendar = Calendar.getInstance();
		calendar.get(Calendar.DAY_OF_MONTH);
		long now = calendar.getTimeInMillis();
		Date date = strToDate(dateStr, DATE_FORMAT);
		calendar.setTime(date);
		long past = calendar.getTimeInMillis();
		
		// 相差的秒数
		long time = (now - past) / 1000;
		
		StringBuffer sb = new StringBuffer();
		if (time > 0 && time < 60) { // 1小时内
			return sb.append(time + "秒前").toString();
		} else if (time > 60 && time < 3600) {
			return sb.append(time / 60+"分钟前").toString();
		} else if (time >= 3600 && time < 3600 * 24) {
			return sb.append(time / 3600 +"小时前").toString();
		}else if (time >= 3600 * 24 && time < 3600 * 48) {
			return sb.append("昨天").toString();
		}else if (time >= 3600 * 48 && time < 3600 * 72) {
			return sb.append("前天").toString();
		}else if (time >= 3600 * 72) {
			return dateToString(dateStr, DATE_FORMAT);
		}
		return dateToString(dateStr, DATE_FORMAT);
	}