how to access blank cells from excel file using apache-tika - java

I am using Apache-Tika-1.13 to read and work with the excel file contents, I am working good with it but I have problem when I access excel file that contains blank cells. I need to access that blank cells, do Tika provides any way to access blank cells with it's latest release?

No. Apache Tika provides a consistent, easy to use and simplified view across a wide range of file formats. As such, not everything possible with the underlying libraries is possible with Tika.
You'll need to step down to Apache POI, the library that Tika uses for Excel files, if you want fine-grained control over blank and missing cells. Then, see the POI documentation on iterating over cells, including with missing/blank cell control for how to do what you want

Related

Is there any way to extract charts from excel and convert them to image format using java?

I am working on an application that generates a xdoc output with a series of charts and tables, whose data comes from a given excel file. Currently I have been able to generate the necessary charts and tables managing the data with Apache Poi and generating the actual charts in a separate excel file using GCExcel, nevertheless, Apache does not include support to turn XSSFChart objecs into images in order to insert them into the document, and GCexcel's unlicensed version doesn't allow me to exoprt charts to images either. Anybody knows a way in which I can work around this issue?
Check out Spire.XLS library.
Download the free version here
Read what you can do using the library (features)
Official tutorial
Convert the excel file to image
I am not sure if this will actually work because I did not implement something like this before.

Generating line-graphs in Java for .xls files

Are there any libraries out there that can be used to generate line-graphs and export them to a .xls file?
Check out Apache POI (http://poi.apache.org/). However you need to use a limited workaround for this to work.
"You can not [sic] currently create charts. You can however create a chart in Excel, modify the chart data values using HSSF and write a new spreadsheet out. This is possible because POI attempts to keep existing records intact as far as possible." (http://poi.apache.org/spreadsheet/limitations.html)
You could also look into using the JExcelAPI (http://sourceforge.net/projects/jexcelapi/), but I have no familiarity with its limitations.

How do I create form controls (radio, checkbox, buttons, etc.) in Excel using Apache POI (Java)?

Is it possible for me to produce form controls for Excel with Apache POI library using Java? If this is not possible, what are the alternative?
I really need this to accomplish my works.
Thank in advance.
For Excel 2007 or above, because Apache POI operates on OpenXML, you need to use VML Drawing. The fastest path to produce form controls is to do that manually, then open created xlsx or xlam as a zip archive and look at the /xl/drawings/vmldrawing.vml part. Then read about VML Drawing in OpenXML standard (ECMA-376) for basics on creating VML drawings. The approach is to create vmldrawing.vml part programmatically as regular XML container and fill it with XML code serialized from memory objects supported by Apache POI API appropriately.

Updating a .docx file's page header using Apache POI

How can I update the page header of a .docx file using the Apache POI 3.7 API?
Since your document is in .docx format, you'll need to use the XWPF component API of the POI project. You may find the org.apache.poi.xwpf.usermodel.XWPFHeader class useful (Javadoc), but I've never used it myself.
I couldn't find a good reference for doing this with XWPF, but the following instructions describe accessing headers with HWPF, the analagous interface for older Word documents (AKA .doc docs):
To get at the headers and footers of a Word document, first create a org.apache.poi.hwpf.HWPFDocument. Next, you need to create a org.apache.poi.hwpf.usermodel.HeaderStores, passing it your HWPFDocument. Finally, the HeaderStores gives you access to the headers and footers, including first / even / odd page ones if defined in your document. Additionally, HeaderStores provides a method for removing any macros in the text, which is helpful as many headers and footers do end up with macros in them.
The page those instructions are from implies that header support was never that good in HWPF, let alone XWPF. For more bad news, this other Apache page makes it sound like XWPF development has all but stalled. It's possible that what you want to do is planned but not supported yet.
Check out Writing Microsoft Word Documents in Java With Apache POI
I never worked with Word file before, but done so with POI library for excel stuff, they are quite easy to follow (they model the row, column, sheet etc for excel) so I am assuming they will be equally easy to do for Word files.
And do quick read on their guide Apache POI - HWPF - Java API to Handle Microsoft Word Files
First up, call getHeaderFooterPolicy() on your XWPFDocument, which returns a HeaderFooterPolicy. From that, you can identify the appropriate header for your page (eg Default, First Page etc)
Once you have the appropriate XWPFHeader that you want to change, then you can go about editing it as any other document part. You can fetch the tables, the paragraphs etc, then remove them, add new ones, change the text of them etc. It's all the same process then as editing the main document.

Excel to XML code in java?

I need code in java for Excel to XML conversion.
where Excel sheet will be used as the input file and XML file as the output file.we have to read the Excel file Row and column wise and than write that data to XMl file.
please anybody give any Code or URL or any Repository of example,which would be appreciated.
Thanks,
Mishal Shah
Have a look at Apache POI. I'm sure there are some examples there.
This may not be the answer you were looking for, but Excel already has built-in support for XML. If you are using Excel 2007, you will need to enable the Developer tab on the ribbon. From there you can import and export XML schemas and files.
To enable the developer tab:
Click the Microsoft button...
Click Excel Options
Check "Show Developer Tab in the Ribbon"
You will need to create a map by either importing an example XML file that is in the same format as the one you'd like to export, or you can click Source and use a schema (XSD) file.
From there, you just need to map the elements in your XML Map to the data in your sheet, then export the data to an XML file.
I did a "Read Excel into a DefaultTableModel" in about 20 lines with the JExcel API. It was very nice and simple to use.
JExcel is another option, although I think it has less features and doesn't support the latest excel format like the Apache POI does.
I have done conversion of Excel(xlsx) to xml in Java recently. I assumed each row in excel as a single object here. Here are the steps I followed:-
Read Excel file using Apache POI
Created a xsd file and generated corresponding classes
Read each row created, created corresponding objects and initilaized values using the generated getter/setter methods in the classes
Added the objects to an arraylist which holds only objects the same type
Using Jaxb Marshelled the arraylist object to an output file
Ready to provide code if required Here's where you can start https://sites.google.com/site/arjunwebworld/Home/programming/jaxb-example

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