我有:
String date = "2010-10-9 12:00:00";
我想解析该字符串,然后从当前日期/时间中减去该日期/时间,以便我可以输出类似于“2 天前”的字符串。
最佳答案
这是我正在使用的辅助类,它扩展了 Android 的标准 DateUtils。它有一个高级逻辑,对于今天的时间戳,它会显示秒或分钟或小时,而对于其他时间戳,它会显示日期。
您可以在 getTimeDiffString
方法中根据需要调整逻辑。作为参数,您将解析您在上述代码中获取的 Date date = formatter.parse(dateString);
的时间戳。
代码逻辑符合您从 Facebook 或 Twitter 了解到的“时间戳显示”。
public class DateTimeUtils extends DateUtils {
private static String mTimestampLabelYesterday;
private static String mTimestampLabelToday;
private static String mTimestampLabelJustNow;
private static String mTimestampLabelMinutesAgo;
private static String mTimestampLabelHoursAgo;
private static String mTimestampLabelHourAgo;
/**
* Singleton contructor, needed to get access to the application context & strings for i18n
* @param context Context
* @return DateTimeUtils singleton instanec
* @throws Exception
*/
public static DateTimeUtils getInstance(Context context) {
mCtx = context;
if (instance == null) {
instance = new DateTimeUtils();
mTimestampLabelYesterday = context.getResources().getString(R.string.WidgetProvider_timestamp_yesterday);
mTimestampLabelToday = context.getResources().getString(R.string.WidgetProvider_timestamp_today);
mTimestampLabelJustNow = context.getResources().getString(R.string.WidgetProvider_timestamp_just_now);
mTimestampLabelMinutesAgo = context.getResources().getString(R.string.WidgetProvider_timestamp_minutes_ago);
mTimestampLabelHoursAgo = context.getResources().getString(R.string.WidgetProvider_timestamp_hours_ago);
mTimestampLabelHourAgo = context.getResources().getString(R.string.WidgetProvider_timestamp_hour_ago);
}
return instance;
}
/**
* Checks if the given date is yesterday.
*
* @param date - Date to check.
* @return TRUE if the date is yesterday, FALSE otherwise.
*/
public static boolean isYesterday(long date) {
final Calendar currentDate = Calendar.getInstance();
currentDate.setTimeInMillis(date);
final Calendar yesterdayDate = Calendar.getInstance();
yesterdayDate.add(Calendar.DATE, -1);
return yesterdayDate.get(Calendar.YEAR) == currentDate.get(Calendar.YEAR) && yesterdayDate.get(Calendar.DAY_OF_YEAR) == currentDate.get(Calendar.DAY_OF_YEAR);
}
public static String[] weekdays = new DateFormatSymbols().getWeekdays(); // get day names
public static final long millisInADay = 1000 * 60 * 60 * 24;
...
/**
* Displays a user-friendly date difference string
* @param timedate Timestamp to format as date difference from now
* @return Friendly-formatted date diff string
*/
public String getTimeDiffString(long timedate) {
Calendar startDateTime = Calendar.getInstance();
Calendar endDateTime = Calendar.getInstance();
endDateTime.setTimeInMillis(timedate);
long milliseconds1 = startDateTime.getTimeInMillis();
long milliseconds2 = endDateTime.getTimeInMillis();
long diff = milliseconds1 - milliseconds2;
long hours = diff / (60 * 60 * 1000);
long minutes = diff / (60 * 1000);
minutes = minutes - 60 * hours;
long seconds = diff / (1000);
boolean isToday = DateTimeUtils.isToday(timedate);
boolean isYesterday = DateTimeUtils.isYesterday(timedate);
if (hours > 0 && hours < 12) {
return hours==1? String.format(mTimestampLabelHourAgo,hours) : String.format(mTimestampLabelHoursAgo,hours);
} else if (hours <= 0) {
if (minutes > 0)
return String.format(mTimestampLabelMinutesAgo,minutes);
else {
return mTimestampLabelJustNow;
}
} else if (isToday) {
return mTimestampLabelToday;
} else if (isYesterday) {
return mTimestampLabelYesterday;
} else if (startDateTime.getTimeInMillis() - timedate < millisInADay * 6) {
return weekdays[endDateTime.get(Calendar.DAY_OF_WEEK)];
} else {
return formatDateTime(mCtx, timedate, DateUtils.FORMAT_NUMERIC_DATE);
}
}
}
而 strings.xml 包含:
<string name="WidgetProvider_timestamp_today">Today</string>
<string name="WidgetProvider_timestamp_yesterday">Yesterday</string>
<string name="WidgetProvider_timestamp_hour_ago">%s hour ago</string>
<string name="WidgetProvider_timestamp_hours_ago">%s hours ago</string>
<string name="WidgetProvider_timestamp_minutes_ago">%s minutes ago</string>
<string name="WidgetProvider_timestamp_just_now">Just now</string>
关于Java(Android) 将 SQLite 日期转换为 "x days ago",我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/3910042/