Android日期時間格式國際化

在做多語言版本的時候，日期時間的格式話是一個很頭疼的事情，幸好Android提供了DateFormate，可以根據指定的語言區域的默認格式來格式化。直接貼代碼：
public static CharSequence formatTimeInListForOverSeaUser(
final Context context, final long time, final boolean simple,
Locale locale) {
final GregorianCalendar now = new GregorianCalendar();

// special time
if (time < MILLSECONDS_OF_HOUR) {
return "";
}

// today
final GregorianCalendar today = new GregorianCalendar(
now.get(GregorianCalendar.YEAR),
now.get(GregorianCalendar.MONTH),
now.get(GregorianCalendar.DAY_OF_MONTH));
final long in24h = time - today.getTimeInMillis();
if (in24h > 0 && in24h <= MILLSECONDS_OF_DAY) {
java.text.DateFormat df = java.text.DateFormat.getTimeInstance(
java.text.DateFormat.SHORT, locale);
return "" + df.format(time);
}

// yesterday
final long in48h = time - today.getTimeInMillis() + MILLSECONDS_OF_DAY;
if (in48h > 0 && in48h <= MILLSECONDS_OF_DAY) {
return simple ? context.getString(R.string.fmt_pre_yesterday)
: context.getString(R.string.fmt_pre_yesterday)
+ " "
+ java.text.DateFormat.getTimeInstance(
java.text.DateFormat.SHORT, locale).format(
time);
}

final GregorianCalendar target = new GregorianCalendar();
target.setTimeInMillis(time);

// same week
if (now.get(GregorianCalendar.YEAR) == target
.get(GregorianCalendar.YEAR)
&& now.get(GregorianCalendar.WEEK_OF_YEAR) == target
.get(GregorianCalendar.WEEK_OF_YEAR)) {
java.text.SimpleDateFormat sdf = new java.text.SimpleDateFormat("E", locale);
final String dow = "" + sdf.format(time);
return simple ? dow : dow
+ java.text.DateFormat.getTimeInstance(
java.text.DateFormat.SHORT, locale).format(time);
}

// same year
if (now.get(GregorianCalendar.YEAR) == target
.get(GregorianCalendar.YEAR)) {
return simple ? java.text.DateFormat.getDateInstance(
java.text.DateFormat.SHORT, locale).format(time)
: java.text.DateFormat.getDateTimeInstance(
java.text.DateFormat.SHORT,
java.text.DateFormat.SHORT, locale).format(time);
}

return simple ? java.text.DateFormat.getDateInstance(
java.text.DateFormat.SHORT, locale).format(time)
: java.text.DateFormat.getDateTimeInstance(
java.text.DateFormat.SHORT, java.text.DateFormat.SHORT,
locale).format(time);
}

注意這裏用的是java.text.DateFormat，還有另外一個java.text.format.DateFormat,後者不能指定locale。
詳細介紹見：http://developer.android.com/reference/java/text/DateFormat.html