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git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@352791 13f79535-47bb-0310-9956-ffa450edef68
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Glen Stampoultzis 2002-07-20 12:51:07 +00:00
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@ -7,9 +7,9 @@
Why is reading a simple sheet taking so long? Why is reading a simple sheet taking so long?
</question> </question>
<answer> <answer>
You've probably enabled logging. Logging is intended only for You've probably enabled logging. Logging is intended only for
autopsie style debugging. Having it enabled will reduce performance autopsie style debugging. Having it enabled will reduce performance
by a factor of at least 100. Logging is helpful for understanding by a factor of at least 100. Logging is helpful for understanding
why POI can't read some file or developing POI itself. Important why POI can't read some file or developing POI itself. Important
errors are thrown as exceptions, which means you probably don't need errors are thrown as exceptions, which means you probably don't need
logging. logging.
@ -62,24 +62,25 @@
<answer> <answer>
Excel stores dates as numbers therefore the only way to determine if a cell is 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. There is a helper method actually stored as a date is to look at the formatting. There is a helper method
in HSSFDateUtil (since the 1.7.0-dev release) that checks for this. in HSSFDateUtil (since the 1.7.0-dev release) that checks for this.
Thanks to Jason Hoffman for providing the solution. Thanks to Jason Hoffman for providing the solution.
<source> <source>
case HSSFCell.CELL_TYPE_NUMERIC: case HSSFCell.CELL_TYPE_NUMERIC:
double d = cell.getNumericCellValue(); double d = cell.getNumericCellValue();
// test if a date! // test if a date!
if (HSSFDateUtil.isCellDateFormatted(cell)) { if (HSSFDateUtil.isCellDateFormatted(cell)) {
// format in form of M/D/YY // format in form of M/D/YY
cal.setTime(HSSFDateUtil.getJavaDate(d)); cal.setTime(HSSFDateUtil.getJavaDate(d));
cellText = cellText =
(String.valueOf(cal.get(Calendar.YEAR))).substring(2); (String.valueOf(cal.get(Calendar.YEAR))).substring(2);
cellText = cal.get(Calendar.MONTH)+1 + "/" + cellText = cal.get(Calendar.MONTH)+1 + "/" +
cal.get(Calendar.DAY_OF_MONTH) + "/" + cal.get(Calendar.DAY_OF_MONTH) + "/" +
cellText; cellText;
} }
</source> </source>
</answer> </answer>
</faq> </faq>
<faq> <faq>
@ -88,8 +89,8 @@
</question> </question>
<answer> <answer>
<p> <p>
The problem usually manifests itself as the junk characters being shown on The problem usually manifests itself as the junk characters being shown on
screen. The problem persists even though you have set the correct mime type. screen. The problem persists even though you have set the correct mime type.
</p> </p>
<p> <p>
The short answer is, dont depend on IE to display a binary file type you an attachment properly if you stream it via a The short answer is, dont depend on IE to display a binary file type you an attachment properly if you stream it via a
@ -98,29 +99,35 @@
<p> <p>
The problem in most versions of IE is that it does not use the mime type on 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 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 on the request. Thus you might want to add a
string. For example <em>http://yourserver.com/myServelet.xls?param1=xx</em>. This is <strong>.xls</strong> to your request
string. For example
<em>http://yourserver.com/myServelet.xls?param1=xx</em>. This is
easily accomplished through URL mapping in any servlet container. Sometimes 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 a request like
known to work. <em>http://yourserver.com/myServelet?param1=xx&amp;dummy=file.xls</em> is also
known to work.
</p> </p>
<p> <p>
To guarantee opening the file properly in Excel from IE, write out your file to a To guarantee opening the file properly in Excel from IE, write out your file to a
temporary file under your web root from your servelet. Then send an http response temporary file under your web root from your servelet. Then send an http response
to the browser to do a client side redirection to your temp file. (If you do a to the browser to do a client side redirection to your temp file. (If you do a
server side redirect using RequestDispatcher, you will have to add .xls to the server side redirect using RequestDispatcher, you will have to add .xls to the
request as mentioned above.) request as mentioned above.)
</p> </p>
<p> <p>
Note also that 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 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 generating process is heavy, it makes sense to write out to a temporary file, so that multiple
requests happen for a static file. requests happen for a static file.
</p> </p>
<p> <p>
None of this is particular to Excel. The same problem arises when you try to None of this is particular to Excel. The same problem arises when you try to
generate any binary file dynamically to an IE client. For example, if you generate generate any binary file dynamically to an IE client. For example, if you generate
pdf files using <link href="http://xml.apache.org/fop">FOP</link>, you will come across many of the same issues. pdf files using
<link href="http://xml.apache.org/fop">FOP</link>, you will come across many of the same issues.
</p> </p>
<!-- Thanks to Avik for the answer --> <!-- Thanks to Avik for the answer -->
</answer> </answer>
@ -130,13 +137,24 @@
I want to set a cell format (Data format of a cell) of a excel sheet as###,###,###.#### or ###,###,###.0000. Is it possible using POI ? I want to set a cell format (Data format of a cell) of a excel sheet as###,###,###.#### or ###,###,###.0000. Is it possible using POI ?
</question> </question>
<answer> <answer>
HSSF does not yet support custom data formats, however, it should be a <p>
reasonably easy facillity to add and we'll gladly accept contributions HSSF does not yet support custom data formats, however, it should be a
in this area. reasonably easy facillity to add and we'll gladly accept contributions
in this area.
These are the built in formats that it does support: These are the built in formats that it does support:
<link href="http://jakarta.apache.org/poi/javadocs/javasrc/org/apache/poi/hssf/usermodel/HSSFDataFormat_java.html#HSSFDataFormat">http://jakarta.apache.org/poi/javadocs/javasrc/org/apache/poi/hssf/usermodel/HSSFDataFormat_java.html#HSSFDataFormat</a>
<link href="http://jakarta.apache.org/poi/javadocs/javasrc/org/apache/poi/hssf/usermodel/HSSFDataFormat_java.html#HSSFDataFormat">http://jakarta.apache.org/poi/javadocs/javasrc/org/apache/poi/hssf/usermodel/HSSFDataFormat_java.html#HSSFDataFormat</link>
</p>
</answer>
</faq>
<faq>
<question>
How do I add a border around a merged cell?
</question>
<answer>
Add blank cells around where the cells normally would have been and set the borders individually for each cell.
</answer> </answer>
</faq> </faq>
</faqs> </faqs>