A question that seems to have quite a few options for Python, but none for Java after googling for two days. Really really could use some help all I have found so far is a recommendation to use gaeVFS to build an excel file from the xml components and then zip it all together which sounds like a slap in the face. Oh yes and if you were wondering I am questioning my use of Java rather than python but at 5,000 lines of code it would be insane to turn back now...
Other things you might find useful
Client: GWT
Server: Servlets running
on google app engine storing data
into the google data store
Excel file: mandatory, CSV isn't good
enough, no need to save the file just
to be able to "serve" it to the
client i.e. open a "Save As" box.
Have you checked out this api already: Java Excel API ?
You could also take a look at the Apache POI project. You can read and write MS Excel documents with this library.
Take a look at this post.
It's a step by step tutorial on how to generate excel files on google app engine.
Try this :
http://code.google.com/p/gwt-table-to-excel/
google app engine do not support input/output stream classes, you need to use google app engine virtual file system.
Related
First time asking something, let's see if I don't mess up.
My question is, I believe, a simple one:
Can one you use the Document Conversion Tool present in the Google Docs API to convert a PPTX/PPT to ODP (OpenDocument Presentation) without any intent of uploading it to Google Docs.
Basically I just want to use the conversion tool and have the file to save. Is it possible?
Thank a bunch for your time.
Your contribution will keep the entire World spinning.. well, at least my World :P
No, it is not possible to use the API to convert file into different formats if they are not uploaded to Google Drive.
You can always upload a file to Drive, convert it to a different format and then delete the original file, but I don't why you might want to do that :)
I has a excel file with 4 excel sheets in it. Now i want to read or write to required excel sheets using java without using any third party lib.
I know i can read and write data using FileInputStream and FileOutputStream respecitvely. But i can handle the work sheets??
No, you can'not, There is numerous way in Java for reading/writing files, but there is no built-in support for MS Office/Excel spreadsheets. http://poi.apache.org/ - is a key to victory.
If your goal is to interface with data from an excel sheet from your Java application, I'd suggest to use the solutions suggested by other posters, it will save you a lot of work.
If, however, you want to be able to read excel files from Java (or any other programming language for that matter) 'just because you can' then you could take a look at this file and read the instructions on this web-page. I would warn you that it would take considerably more time to implement your own API if you base it only on the file-specs that are publicly available. You might want to check out the work done by the people from the Apache POI project to get an idea of how to approach it. Or (even better) contribute to the project. Here you can find out how to go about doing that
By "not depend on automation", I mean that it should not require a Microsoft Office installation to work; let alone interact with a live instance of a Microsoft Office component. One such library is Aspose.Total for Java. Are there any more out there?
Another solution I'm considering is to use OpenOffice.org. However, I'm not sure if I'm going to run into the same problems as with Microsoft Office as detailed here.
For Office Documents: http://poi.apache.org/
I have not tried this myself, but Apache usually deliver good libraries
For just Excel: JExcel API for Java
I use this for one application, and it works quite well. May use a fair bit of RAM for larger documents.
One designed specifically to with with the newer XML formats is docx4j: http://dev.plutext.org/trac/docx4j
There are two further answers for this question. Depending on your application.
can borrow from the OpenOffice library code that deals with opening and saving MS Office files. (See: http://www.artofsolving.com/opensource/jodconverter or jOpenDocument )
You might just use OpenOffice itself by scripting or automating that.
I faced this question a while back with a Ruby app and because I was in control of the source document, I got the originator to save things as HTML format and used Tidy to filter the junk. Another option it to find a tool to convert the Office files to RTF which is more generic.
Another to consider ...
LibreOffice looks useful.
jExcelAPI if you just want excel.
Finally there are some opportunities on sourceForge, try this search: http://sourceforge.net/search/?q=java+ms+office
You may find spreadsheets BIG unless you use OpenOffice or MS Office because you need to have a fancy shamancy virtual sparse matrix to do what they do well.
ODF Toolkit - http://odftoolkit.org
I am searching on ways to make a small app using GWT for converting documents
from one format to other.
Mainly these formats .doc , .pdf , .odt , .rtf.. and maybe a couple
more.
Has anyone tried this before??
I came across the library JODConverter but it needs open office to be
already installed and i don't really know how many people have used it
with gwt in past.
Please give me some starting pointers, or if anyone has experience
with this kind of app, do share.
Thanks and regards,
Rohit
I was looking into implementing something like this a few month ago.
Since GWT compiles your code to JavaScript there is no way for you to do that on the client side, JavaScript can't access the file system.
So you would need to upload the file to the server first and do the conversion on the server side and send the converted file back.
I have never heard of JODConverter before, the the library I wanted to use was Apache POI . Unfortunately I can't tell you anything about it, because I haven't tried it yet.
It sounds like JOD Converter is precisely what you need since you're looking at multi format conversions from Java. You would install OpenOffice on your server and link it up with JOD Converter. When a document is uploaded, your application would call JOD Converter to perform the conversion and stream the converted document back to the caller. Alternatively you can put the file somewhere, and send a link (URL) back to the caller so they can fetch the document. You can also look at JOD Reports or Docmosis if you need to manipulate the documents.
GWT is mostly a client side toolkit. Are you trying to make a tool that does all the conversion on the client side, with no help from the server? In that case, you should be looking for JavaScript libraries that can read/convert all those formats. If you are planning to have the user upload their files to the server, then you can use whatever technology you want on the server, and just use GWT for the UI.
The interop library is slow and needs MS Office installed.
Many times you don't want to install MS Office on servers.
I'd like to use Apache POI, but I'm on .NET.
I need only to extract the text portion of the files, not creating nor "storing information" in Office files.
I need to tell you that I've got a very large document library, and I can't convert it to newer XML files.
I don't want to write a parser for the binaries files.
A library like Apache POI does this for us. Unfortunately, it is only for the Java platform. Maybe I should consider writing this application in Java.
I am still not finding an open source alternative to POI in .NET, I think I'll write my own application in Java.
For all MS Office versions:
You could use the third-party components like TX Text Controls for Word and TMS Flexcel Studio for Excel
For the new Office (2007):
You could do some basic stuff using .net functionality from system.io.packaging. See how at http://msdn.microsoft.com/en-us/library/bb332058.aspx
For the old Office (before 2007):
The old Office formats are now documented: http://www.microsoft.com/interop/docs/officebinaryformats.mspx. If you want to do something really easy you might consider trying it. But be aware that these formats are VERY complex.
Check out the Aspose components. They are designed to mimic the Interop functionality without requiring a full Office install on a server.
As the new docx formats are inherently XML based files, you can create and manipulate them programmatically with standard XML DOM techniques, once you know the structure.
The files are basically zip archives with an alternate file extension. Use the System.IO.Packaging namespace to get access to the internal elements of the file, then open them into a XmlDocument to perform the manipulation.
There are examples available for doing this, and the Office Open XML project on SourceForge may be worth looking at for inspiration.
As for the older binary formats, these were proprietary to MS, and the only way you're likely to get at the content from within is through the Office object model (requires an Office install), or a third party file converter/parser.
Unfortunately there's nothing first party and native to the .NET platform to work with these files.
What do you need to do with those file? If you just want to stream them to the user, then the basic file streams are fine. If you want to create new files (perhaps based on a template) to send to the user that the user can open in Office, there are a variety or work-arounds.
If you're actually keeping data in Office documents for use by your web site, you're doing it wrong. Office documents, even Excel spreadsheets and access databases, are not really an appropriate choice for use with an interactive web site.
If the document is in word 2007 format, you can use the system.io.packaging library to interact with it programatically.
RWendi
In Java world, there is also JExcelApi. It is very clearly written, from what I was able to see, much cleaner then POI. So maybe even a port of that code to .NET is not out of the question, depending of course you have enough of time on your hands.
OpenOffice.
You can program against it and have it do a lot for you, without spending the money on a license for the server, or have the vulnerability associated with it on your server.
Microsoft Excel workbooks can be read using an ODBC driver (or is it an OLE DB driver? can't remember) that makes the workbook look like a database table. But I don't know whether that driver is available without the Office Suite itself.
You can use OpenOffice. It has a command-line conversion tool:
Conversion Howto
In short, you define a macro in OpenOffice and you call that macro with a command-line
argument to OpenOffice. In that argument the name of the local file (the Office file) is
encoded.
It's not a great sollution, but it should be workable.