Hi Dennis, Thanks for this effort, it looks like a very interesting supplement to the POI project.
If your hypothesis about the 65536 method limit is correct then the problem is in the poi-ooxml-schema.jar, this is where compiled XmlBeans for OOXML are stored. This file contains xml beans for all OOXML modules - document, spreadsheet, presentation and common. In short, poi-ooxml-schemas.jar is a truncated version of the full ooxml-schemas.jar which contains only classes actually used in POI. The criteria to put a xml bean in poi-ooxml-schemas.jar is whether it is referenced in the ooxml test cases, that is, we run ooxml tests against the full ooxml-schemas.jar, see what xml beans are loaded in the junit class loader and copy those to the "light" poi-ooxml-schemas.jar. If you are interested only in the SpreadshetML beans then you can try to make it smaller. The idea is to run only spreadsheetML tests. In POI's buuld.xml there is a macro called ooxml-test-runner. You want to modify it and run only tests for the "xlsf" module. The size of the produced poi-ooxml-schema.jar will be smaller, hopefully below the 65536 method limit. P.S. Would you like to put a reference to your project on the POI web site? We can create a "Related Project" section and put a reference to android-spreadsheet there along with a short description. Questions about POI on Android become common on the POI mailing lists and a link on the POI web site may draw new contributors to your project. If you are interested, we can work on that . Regards,Yegor On Mon, Oct 31, 2011 at 7:02 AM, Dennis Sheil <dsh...@vartmp.com> wrote: > Hi, > > I wanted to see the POI HSSF/XSSF project on Android, so I did a port > to Android. I did a very basic spreadsheet, which can be seen here: > > https://github.com/dennis-sheil/android-spreadsheet > > The main reason the spreadsheet is so basic is that the first thing I > did was implement a very basic spreadsheet frame. Then I added HSSF > functionality. Then I added some more basic spreadsheet > functionality. So to be clear, I at this point had (and still have) a > working Android project (a spreadsheet) that implements Apache POI > HSSF functionality successfully. > > This is where the tl;dr part for some reading this might start. If > you're not interested in Apache POI XSSF being ported to Android, you > can stop reading now. > > So after implementing HSSF successfully, I then tried to implement > XSSF - and got stuck on that. The problem is not per se with Apache > POI XSSF. The problem is with an Android concept called the "Dalvik > executable". You can Google that if you want. The Android > development process entails Java class files being converted into > these Dalvik executable files. Remember Android does not run a Java > VM but a Dalvik VM. The problem with these Dalvik executable files is > that, according to Google they have a 65536 ( > http://code.google.com/p/android/issues/detail?id=7147 ) method limit > for Dalvik executable files. With all those jar files I had as > reference libraries for XSSF going into the Dalvik (xmlbeans, > poi-ooxml, log4j etc., including a schemas file even more stripped > down than the stripped down schemas file that Apache put up), the > 65536 method limit kept being hit. > > So there are two solutions I see for getting XSSF onto Android: > > 1) Keep whittling down at that schemas file and so forth to get under > 65536 methods, and put out a project with one Dalvik executable. This > is the method that you people who are more familiar with POI than > Android would be best at, and the one to think about first if you > don't know Android pretty well. > > 2) Android has methods of loading multiple Dalvik Executable files > into one Android project ( > http://android-developers.blogspot.com/2011/07/custom-class-loading-in-dalvik.html > ). So it can be worked at from that angle as well. > > Anyhow, as POI HSSF and XSSF are released under the Apache License, > version 2, I thought it would be a good idea to release my port of POI > HSSF to Android under the same license, so that is what I did. Any > XSSF work would be under the same license as well. I'm open to > suggestions on this front, we can all work together. My main concern > is getting not just HSSF, but XSSF onto Android as well. If anyone is > interested in helping me take a crack at bringing XSSF to Android, > this is my e-mail address, and the code up on Github is at > https://github.com/dennis-sheil/android-spreadsheet . The license is > Apache Version 2 for everything, so whether it's patched to my tree on > Github, or brought back into POI, or whatever, anything is fine by me. > I'd just like to see XSSF on Android, alongside HSSF, which is > working fine. So anyone interested can contact me, or reply to the > mailing list. I posted this here since I saw some people talking > about this in the past, and figured people would be interested (and > have some POI expertise as well). > > Thanks, > Dennis Sheil > > --------------------------------------------------------------------- > To unsubscribe, e-mail: dev-unsubscr...@poi.apache.org > For additional commands, e-mail: dev-h...@poi.apache.org > > --------------------------------------------------------------------- To unsubscribe, e-mail: dev-unsubscr...@poi.apache.org For additional commands, e-mail: dev-h...@poi.apache.org
