Add util method to check date formatting in Excel, submitted by Jason Hoffman

git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@352695 13f79535-47bb-0310-9956-ffa450edef68
This commit is contained in:
Avik Sengupta 2002-06-13 17:17:24 +00:00
parent 65400bbe1b
commit ffe4a6d83e
2 changed files with 53 additions and 49 deletions

View File

@ -37,7 +37,7 @@
Does HSSF support protected spreadsheets?
</question>
<answer>
Protecting a spreadsheet encripts it. We wont touch encription because we're not legally educated
Protecting a spreadsheet encrypts it. We wont touch encryption because we're not legally educated
and don't understand the full implications of trying to implement this. If you wish to have a go
at this feel free to add it as a plugin module. We wont be hosting it here however.
</answer>
@ -48,20 +48,15 @@
</question>
<answer>
Excel stores dates as numbers therefore the only way to determine if a cell is
actually stored as a date is to look at the formatting. This solution from
Jason Hoffman:
<p>
Okay, here is a little code I used to determine if the cell was a number or
date, and then format appropriately. I hope it helps. I keep meaning to
submit a patch with the helper method below.... but just haven't had a
chance.
</p>
actually stored as a date is to look at the formatting. There is a helper method
in HSSFDateUtil (since after 1.6.0-dev) that checks for this.
Thanks to Jason Hoffman for providing the solution.
<source>
/////// code snippet ////////////
case HSSFCell.CELL_TYPE_NUMERIC:
case HSSFCell.CELL_TYPE_NUMERIC:
double d = cell.getNumericCellValue();
// test if a date!
if (isCellDateFormatted(cell)) {
if (HSSFDateUtil.isCellDateFormatted(cell)) {
// format in form of M/D/YY
cal.setTime(HSSFDateUtil.getJavaDate(d));
cellText =
@ -70,45 +65,13 @@ case HSSFCell.CELL_TYPE_NUMERIC:
cal.get(Calendar.DAY_OF_MONTH) + "/" +
cellText;
}
/////// end code snippet ////////////
// HELPER METHOD BELOW TO DETERMINE IF DATE
// method to determine if the cell is a date, versus a number...
public static boolean isCellDateFormatted(HSSFCell cell) {
boolean bDate = false;
double d = cell.getNumericCellValue();
if ( HSSFDateUtil.isValidExcelDate(d) ) {
HSSFCellStyle style = cell.getCellStyle();
int i = style.getDataFormat();
switch(i) {
// Internal Date Formats as described on page 427 in
// Microsoft Excel Dev's Kit...
case 0x0e:
case 0x0f:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
case 0x14:
case 0x15:
case 0x16:
case 0x2d:
case 0x2e:
case 0x2f:
bDate = true;
break;
default:
bDate = false;
break;
}
}
return bDate;
}
</source>
</answer>
</faq>
<faq>
<question>
I'm trying to stream an XLS file from a servlet and I'm having some trouble. What's the problem?
</question>
@ -125,8 +88,9 @@ public static boolean isCellDateFormatted(HSSFCell cell) {
The problem in most versions of IE is that it does not use the mime type on
the HTTP response to determine the file type; rather it uses the file extension
on the request. Thus you might want to add a <strong>.xls</strong> to your request
string. For example http://yourserver.com/myServelet.xls?param1=xx. Sometimes
a request like http://yourserver.com/myServelet?param1=xx&amp;dummy=file.xls is also
string. For example <em>http://yourserver.com/myServelet.xls?param1=xx</em>. This is
easily accomplished through URL mapping in any servlet container. Sometimes
a request like <em>http://yourserver.com/myServelet?param1=xx&amp;dummy=file.xls</em> is also
known to work.
</p>
<p>
@ -137,7 +101,7 @@ public static boolean isCellDateFormatted(HSSFCell cell) {
request as mentioned above.)
</p>
<p>
Note also that sometimes when you request a document that is opened with an
Note also that when you request a document that is opened with an
external handler, IE sometimes makes two requests to the webserver. So if your
generating process is heavy, it makes sense to write out to a temporary file, so that multiple
requests happen for a static file.

View File

@ -141,6 +141,46 @@ public class HSSFDateUtil
return null;
}
}
/**
* Check if a cell contains a date
* Since dates are stored internally in Excel as double values
* we infer it is a date if it is formatted as such.
*/
public static boolean isCellDateFormatted(HSSFCell cell) {
if (cell == null) return false;
boolean bDate = false;
double d = cell.getNumericCellValue();
if ( HSSFDateUtil.isValidExcelDate(d) ) {
HSSFCellStyle style = cell.getCellStyle();
int i = style.getDataFormat();
switch(i) {
// Internal Date Formats as described on page 427 in
// Microsoft Excel Dev's Kit...
case 0x0e:
case 0x0f:
case 0x10:
case 0x11:
case 0x12:
case 0x13:
case 0x14:
case 0x15:
case 0x16:
case 0x2d:
case 0x2e:
case 0x2f:
bDate = true;
break;
default:
bDate = false;
break;
}
}
return bDate;
}
/**
* Given a double, checks if it is a valid Excel date.