Added a Formatter parameter to DateUtils.formatDateRange
DateUtils.formatDateRange is using String.format which isn't efficient for
formatting large number of strings. I have added the Formatter parameter which
allows the caller to reuse the formatter of subsequent calls for faster
performance.
diff --git a/api/current.xml b/api/current.xml
index eeeab80..c92b018 100644
--- a/api/current.xml
+++ b/api/current.xml
@@ -126565,6 +126565,27 @@
<parameter name="flags" type="int">
</parameter>
</method>
+<method name="formatDateRange"
+ return="java.util.Formatter"
+ abstract="false"
+ native="false"
+ synchronized="false"
+ static="true"
+ final="false"
+ deprecated="not deprecated"
+ visibility="public"
+>
+<parameter name="context" type="android.content.Context">
+</parameter>
+<parameter name="formatter" type="java.util.Formatter">
+</parameter>
+<parameter name="startMillis" type="long">
+</parameter>
+<parameter name="endMillis" type="long">
+</parameter>
+<parameter name="flags" type="int">
+</parameter>
+</method>
<method name="formatDateTime"
return="java.lang.String"
abstract="false"
diff --git a/core/java/android/text/format/DateUtils.java b/core/java/android/text/format/DateUtils.java
index 1a4eb699..9dd8ceb 100644
--- a/core/java/android/text/format/DateUtils.java
+++ b/core/java/android/text/format/DateUtils.java
@@ -25,7 +25,9 @@
import java.util.Calendar;
import java.util.Date;
+import java.util.Formatter;
import java.util.GregorianCalendar;
+import java.util.Locale;
import java.util.TimeZone;
/**
@@ -1040,6 +1042,31 @@
/**
* Formats a date or a time range according to the local conventions.
+ * <p>
+ * Note that this is a convenience method. Using it involves creating an
+ * internal {@link java.util.Formatter} instance on-the-fly, which is
+ * somewhat costly in terms of memory and time. This is probably acceptable
+ * if you use the method only rarely, but if you rely on it for formatting a
+ * large number of dates, consider creating and reusing your own
+ * {@link java.util.Formatter} instance and use the version of
+ * {@link #formatDateRange(Context, long, long, int) formatDateRange}
+ * that takes a {@link java.util.Formatter}.
+ *
+ * @param context the context is required only if the time is shown
+ * @param startMillis the start time in UTC milliseconds
+ * @param endMillis the end time in UTC milliseconds
+ * @param flags a bit mask of options See
+ * {@link #formatDateRange(Context, long, long, int) formatDateRange}
+ * @return a string containing the formatted date/time range.
+ */
+ public static String formatDateRange(Context context, long startMillis,
+ long endMillis, int flags) {
+ Formatter f = new Formatter(new StringBuilder(50), Locale.getDefault());
+ return formatDateRange(context, f, startMillis, endMillis, flags).toString();
+ }
+
+ /**
+ * Formats a date or a time range according to the local conventions.
*
* <p>
* Example output strings (date formats in these examples are shown using
@@ -1181,14 +1208,17 @@
* instead of "December 31, 2008".
*
* @param context the context is required only if the time is shown
+ * @param formatter the Formatter used for formatting the date range.
+ * Note: be sure to call setLength(0) on StringBuilder passed to
+ * the Formatter constructor unless you want the results to accumulate.
* @param startMillis the start time in UTC milliseconds
* @param endMillis the end time in UTC milliseconds
* @param flags a bit mask of options
*
- * @return a string containing the formatted date/time range.
+ * @return the formatter with the formatted date/time range appended to the string buffer.
*/
- public static String formatDateRange(Context context, long startMillis,
- long endMillis, int flags) {
+ public static Formatter formatDateRange(Context context, Formatter formatter, long startMillis,
+ long endMillis, int flags) {
Resources res = Resources.getSystem();
boolean showTime = (flags & FORMAT_SHOW_TIME) != 0;
boolean showWeekDay = (flags & FORMAT_SHOW_WEEKDAY) != 0;
@@ -1423,8 +1453,7 @@
if (noMonthDay && startMonthNum == endMonthNum) {
// Example: "January, 2008"
- String startDateString = startDate.format(defaultDateFormat);
- return startDateString;
+ return formatter.format("%s", startDate.format(defaultDateFormat));
}
if (startYear != endYear || noMonthDay) {
@@ -1436,10 +1465,9 @@
// The values that are used in a fullFormat string are specified
// by position.
- dateRange = String.format(fullFormat,
+ return formatter.format(fullFormat,
startWeekDayString, startDateString, startTimeString,
endWeekDayString, endDateString, endTimeString);
- return dateRange;
}
// Get the month, day, and year strings for the start and end dates
@@ -1476,12 +1504,11 @@
// The values that are used in a fullFormat string are specified
// by position.
- dateRange = String.format(fullFormat,
+ return formatter.format(fullFormat,
startWeekDayString, startMonthString, startMonthDayString,
startYearString, startTimeString,
endWeekDayString, endMonthString, endMonthDayString,
endYearString, endTimeString);
- return dateRange;
}
if (startDay != endDay) {
@@ -1496,12 +1523,11 @@
// The values that are used in a fullFormat string are specified
// by position.
- dateRange = String.format(fullFormat,
+ return formatter.format(fullFormat,
startWeekDayString, startMonthString, startMonthDayString,
startYearString, startTimeString,
endWeekDayString, endMonthString, endMonthDayString,
endYearString, endTimeString);
- return dateRange;
}
// Same start and end day
@@ -1522,6 +1548,7 @@
} else {
// Example: "10:00 - 11:00 am"
String timeFormat = res.getString(com.android.internal.R.string.time1_time2);
+ // Don't use the user supplied Formatter because the result will pollute the buffer.
timeString = String.format(timeFormat, startTimeString, endTimeString);
}
}
@@ -1545,7 +1572,7 @@
fullFormat = res.getString(com.android.internal.R.string.time_date);
} else {
// Example: "Oct 9"
- return dateString;
+ return formatter.format("%s", dateString);
}
}
} else if (showWeekDay) {
@@ -1554,16 +1581,15 @@
fullFormat = res.getString(com.android.internal.R.string.time_wday);
} else {
// Example: "Tue"
- return startWeekDayString;
+ return formatter.format("%s", startWeekDayString);
}
} else if (showTime) {
- return timeString;
+ return formatter.format("%s", timeString);
}
// The values that are used in a fullFormat string are specified
// by position.
- dateRange = String.format(fullFormat, timeString, startWeekDayString, dateString);
- return dateRange;
+ return formatter.format(fullFormat, timeString, startWeekDayString, dateString);
}
/**
