src/java/org/apache/poi/POITextExtractor.java

/* ====================================================================
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   this work for additional information regarding copyright ownership.
   The ASF licenses this file to You under the Apache License, Version 2.0
   (the "License"); you may not use this file except in compliance with
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       http://www.apache.org/licenses/LICENSE-2.0

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   distributed under the License is distributed on an "AS IS" BASIS,
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   See the License for the specific language governing permissions and
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package org.apache.poi;

/**
 * Common Parent for Text Extractors
 *  of POI Documents. 
 * You will typically find the implementation of
 *  a given format's text extractor under
 *  org.apache.poi.[format].extractor .
 * @see org.apache.poi.hssf.extractor.ExcelExtractor
 * @see org.apache.poi.hslf.extractor.PowerPointExtractor
 * @see org.apache.poi.hdgf.extractor.VisioTextExtractor
 * @see org.apache.poi.hwpf.extractor.WordExtractor
 */
public abstract class POITextExtractor {
	/** The POIDocument that's open */
	protected POIDocument document;

	/**
	 * Creates a new text extractor for the given document
	 */
	public POITextExtractor(POIDocument document) {
		this.document = document;
	}
	/**
	 * Creates a new text extractor, using the same
	 *  document as another text extractor. Normally
	 *  only used by properties extractors.
	 */
	protected POITextExtractor(POITextExtractor otherExtractor) {
		this.document = otherExtractor.document;
	}
	
	/**
	 * Retrieves all the text from the document.
	 * How cells, paragraphs etc are separated in the text
	 *  is implementation specific - see the javadocs for
	 *  a specific project for details.
	 * @return All the text from the document
	 */
	public abstract String getText();
	
	/**
	 * Returns another text extractor, which is able to
	 *  output the textual content of the document
	 *  metadata / properties, such as author and title.
	 */
	public abstract POITextExtractor getMetadataTextExtractor();
}