improved performance of DateUtil.isCellDateFormatted(), see Bugzilla 48425

git-svn-id: https://svn.apache.org/repos/asf/poi/trunk@893105 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Yegor Kozlov 2009-12-22 07:52:55 +00:00
parent c89aeaee12
commit 3bbde4880c
3 changed files with 60 additions and 20 deletions

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@ -34,6 +34,7 @@
<changes>
<release version="3.7-SNAPSHOT" date="2010-??-??">
<action dev="POI-DEVELOPERS" type="fix">48425 - improved performance of DateUtil.isCellDateFormatted() </action>
<action dev="POI-DEVELOPERS" type="fix">47215 - fixed InterfaceEndRecord to tolerate unexpected record contents </action>
<action dev="POI-DEVELOPERS" type="fix">48415 - improved javadoc on HSSPicture.resize() </action>
<action dev="POI-DEVELOPERS" type="add">added Ant target to install artifacts in local repository </action>

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@ -47,6 +47,13 @@ public class DateUtil {
private static final Pattern TIME_SEPARATOR_PATTERN = Pattern.compile(":");
/**
* The following patterns are used in {@link #isADateFormat(int, String)}
*/
private static final Pattern date_ptrn1 = Pattern.compile("^\\[\\$\\-.*?\\]");
private static final Pattern date_ptrn2 = Pattern.compile("^\\[[a-zA-Z]+\\]");
private static final Pattern date_ptrn3 = Pattern.compile("^[yYmMdDhHsS\\-/,. :\\\\]+[ampAMP/]*$");
/**
* Given a Date, converts it into a double representing its internal Excel representation,
* which is the number of days since 1/1/1900. Fractional days represent hours, minutes, and seconds.
@ -181,6 +188,7 @@ public class DateUtil {
calendar.set(GregorianCalendar.MILLISECOND, millisecondsInDay);
}
/**
* Given a format ID and its format String, will check to see if the
* format represents a date format or not.
@ -206,13 +214,16 @@ public class DateUtil {
}
String fs = formatString;
/*
Normalize the format string. The code below is equivalent
to the following consecutive regexp replacements:
// Translate \- into just -, before matching
fs = fs.replaceAll("\\\\-","-");
// And \, into ,
fs = fs.replaceAll("\\\\,",",");
// And \. into .
fs = fs.replaceAll("\\\\.",".");
fs = fs.replaceAll("\\\\\\.",".");
// And '\ ' into ' '
fs = fs.replaceAll("\\\\ "," ");
@ -220,22 +231,45 @@ public class DateUtil {
// switching stuff, which we can ignore
fs = fs.replaceAll(";@", "");
The code above was reworked as suggested in bug 48425:
simple loop is more efficient than consecutive regexp replacements.
*/
StringBuilder sb = new StringBuilder();
for(int i = 0; i < fs.length(); i++){
char c = fs.charAt(i);
if(i < fs.length() - 1){
char nc = fs.charAt(i + 1);
if(c == '\\'){
switch (nc){
case '-':
case ',':
case '.':
case ' ':
case '\\':
//skip current '\' and continue to the next char
continue;
}
} else if (c == ';' && nc == '@'){
i++;
//skip ";@" duplets
continue;
}
}
sb.append(c);
}
fs = sb.toString();
// If it starts with [$-...], then could be a date, but
// who knows what that starting bit is all about
fs = fs.replaceAll("^\\[\\$\\-.*?\\]", "");
fs = date_ptrn1.matcher(fs).replaceAll("");
// If it starts with something like [Black] or [Yellow],
// then it could be a date
fs = fs.replaceAll("^\\[[a-zA-Z]+\\]", "");
fs = date_ptrn2.matcher(fs).replaceAll("");
// Otherwise, check it's only made up, in any case, of:
// y m d h s - / , . :
// y m d h s - \ / , . :
// optionally followed by AM/PM
if(fs.matches("^[yYmMdDhHsS\\-/,. :]+[ampAMP/]*$")) {
return true;
}
return false;
return date_ptrn3.matcher(fs).matches();
}
/**

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@ -26,6 +26,7 @@ import junit.framework.TestCase;
import org.apache.poi.hssf.HSSFTestDataSamples;
import org.apache.poi.hssf.model.InternalWorkbook;
import org.apache.poi.ss.usermodel.DateUtil;
/**
* Class TestHSSFDateUtil
@ -239,6 +240,10 @@ public final class TestHSSFDateUtil extends TestCase {
"DD-MM-YY", "DD-mm-YYYY",
"dd\\-mm\\-yy", // Sometimes escaped
"dd.mm.yyyy", "dd\\.mm\\.yyyy",
"dd\\ mm\\.yyyy AM", "dd\\ mm\\.yyyy pm",
"dd\\ mm\\.yyyy\\-dd", "[h]:mm:ss",
//YK: TODO "mm:ss.0" is a built-in date format which is not recognized by DateUtil.isInternalDateFormat
// These crazy ones are valid
"yyyy-mm-dd;@", "yyyy/mm/dd;@",