From f7e29b5bacd813c7f0d52884d18b4f32ebd09138 Mon Sep 17 00:00:00 2001 From: Glen Stampoultzis Date: Sat, 20 Jul 2002 12:51:07 +0000 Subject: [PATCH] New FAQ git-svn-id: https://svn.apache.org/repos/asf/jakarta/poi/trunk@352791 13f79535-47bb-0310-9956-ffa450edef68 --- src/documentation/xdocs/faq.xml | 84 ++++++++++++++++++++------------- 1 file changed, 51 insertions(+), 33 deletions(-) diff --git a/src/documentation/xdocs/faq.xml b/src/documentation/xdocs/faq.xml index d7e6108c3..a90101e2f 100644 --- a/src/documentation/xdocs/faq.xml +++ b/src/documentation/xdocs/faq.xml @@ -7,9 +7,9 @@ Why is reading a simple sheet taking so long? - 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 - 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 errors are thrown as exceptions, which means you probably don't need logging. @@ -62,24 +62,25 @@ 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 - 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. + - case HSSFCell.CELL_TYPE_NUMERIC: - double d = cell.getNumericCellValue(); - // test if a date! - if (HSSFDateUtil.isCellDateFormatted(cell)) { - // format in form of M/D/YY - cal.setTime(HSSFDateUtil.getJavaDate(d)); - cellText = - (String.valueOf(cal.get(Calendar.YEAR))).substring(2); - cellText = cal.get(Calendar.MONTH)+1 + "/" + - cal.get(Calendar.DAY_OF_MONTH) + "/" + - cellText; - } + case HSSFCell.CELL_TYPE_NUMERIC: + double d = cell.getNumericCellValue(); + // test if a date! + if (HSSFDateUtil.isCellDateFormatted(cell)) { + // format in form of M/D/YY + cal.setTime(HSSFDateUtil.getJavaDate(d)); + cellText = + (String.valueOf(cal.get(Calendar.YEAR))).substring(2); + cellText = cal.get(Calendar.MONTH)+1 + "/" + + cal.get(Calendar.DAY_OF_MONTH) + "/" + + cellText; + } - + @@ -88,8 +89,8 @@

- 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. + 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.

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 @@

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 .xls to your request - string. For example http://yourserver.com/myServelet.xls?param1=xx. This is + on the request. Thus you might want to add a + .xls to your request + string. For example + http://yourserver.com/myServelet.xls?param1=xx. This is easily accomplished through URL mapping in any servlet container. Sometimes - a request like http://yourserver.com/myServelet?param1=xx&dummy=file.xls is also - known to work. + a request like + http://yourserver.com/myServelet?param1=xx&dummy=file.xls is also + known to work. +

- 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 - 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 + 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 request as mentioned above.)

- 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 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.

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 - pdf files using FOP, you will come across many of the same issues. + pdf files using + FOP, you will come across many of the same issues. +

@@ -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 ? - HSSF does not yet support custom data formats, however, it should be a - reasonably easy facillity to add and we'll gladly accept contributions - in this area. +

+ HSSF does not yet support custom data formats, however, it should be a + 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: - 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 +

+ + + + + How do I add a border around a merged cell? + + + Add blank cells around where the cells normally would have been and set the borders individually for each cell.