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<?xml version="1.0" encoding="UTF-8"?>
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<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V1.3//EN" "./dtd/document-v13.dtd">
<document>
<header>
<title>POI Text Extraction</title>
<authors>
<person id="NB" name="Nick Burch" email="nick@apache.org"/>
</authors>
</header>
<body>
<section><title>Overview</title>
<p>POI provides text extraction for all the supported file
formats. In addition, it provides access to the metadata
associated with a given file, such as title and author.</p>
<p>In addition to providing direct text extraction classes,
POI works closely with the
<link href="http://incubator.apache.org/tika/">Apache Tika</link>
text extraction library. Users may wish to simply utilise
the functionality provided by Tika.</p>
</section>
<section><title>Common functionality</title>
<p>All of the POI text extractors extend from
<em>org.apache.poi.POITextExtractor</em>. This provides a common
method across all extractors, getText(). For many cases, the text
returned will be all you need. However, many extractors do provide
more targetted text extraction methods, so you may wish to use
these in some cases.</p>
<p>All POIFS / OLE 2 based text extractors also extend from
<em>org.apache.poi.POIOLE2TextExtractor</em>. This additionally
provides common methods to get at the <link href="hpfs/">HPFS
document metadata</link>.</p>
<p>All OOXML based text extractors (available in POI 3.5 and later)
also extend from
<em>org.apache.poi.POIOOXMLTextExtractor</em>. This additionally
provides common methods to get at the OOXML metadata.</p>
</section>
<section><title>Text Extractor Factory - POI 3.5 or later</title>
<p>A new class in POI 3.5,
<em>org.apache.poi.extractor.ExtractorFactory</em> provides a
similar function to WorkbookFactory. You simply pass it an
InputStream, a file, a POIFSFileSystem or a OOXML Package. It
figures out the correct text extractor for you, and returns it.</p>
</section>
<section><title>Excel</title>
<p>For .xls files, there is
<em>org.apache.poi.hssf.extractor.ExcelExtractor</em>, which will
return text, optionally with formulas instead of their contents.
Those using POI 3.5 can also use
<em>org.apache.poi.xssf.extractor.XSSFExcelExtractor</em>, to perform
a similar task for .xlsx files.</p>
<p>In addition, there is a second text extractor for .xls files,
<em>org.apache.poi.hssf.extractor.EventBasedExcelExtractor</em>. This
is based on the streaming EventUserModel code, and will generally
deliver a lower memory footprint for extraction. However, it will
have problems correctly outputting more complex formulas, as it
works with records as they pass, and so doesn't have access to all
parts of complex and shared formulas.</p>
</section>
<section><title>Word</title>
<p>For .doc files, in scratchpad there is
<em>org.apache.poi.hwpf.extractor.WordExtractor</em>, which will
return text for your document. Those using POI 3.5 can also use
<em>org.apache.poi.xwpf.extractor.XPFFWordExtractor</em>, to perform
a similar task for .docx files.</p>
</section>
<section><title>PowerPoint</title>
<p>For .ppt files, in scratchpad there is
<em>org.apache.poi.hslf.extractor.PowerPointExtractor</em>, which
will return text for your slideshow, optionally restricted to just
slides text or notes text. Those using POI 3.5 can also use
<em>org.apache.poi.xslf.extractor.XSLFPowerPointExtractor</em>, to
perform a similar task for .pptx files.</p>
</section>
<section><title>Visio</title>
<p>For .vsd files, in scratchpad there is
<em>org.apache.poi.hdgf.extractor.VisioTextExtractor</em>, which
will return text for your file.</p>
</section>
</body>
<footer>
<legal>
Copyright 2005 The Apache Software Foundation or its licensors, as applicable.
$Revision: 639487 $ $Date: 2008-03-20 22:31:15 +0000 (Thu, 20 Mar 2008) $
</legal>
</footer>
</document>
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