website/src/documentation/content/xdocs/userguide/highlighting.xml - pdfbox - Git at Google

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 <!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd">
 <document>
   <header>
     <title>PDFBox - PDF Highlighting</title>
     <meta name="keywords">Java PDF Library, highlight, highlight pdf, highlight pdf text, java</meta>
   </header>
   <body>
     <section>
         <title>Highlighting text in a PDF</title>
         <p>
             There are cases when you might want to highlight text in a PDF document.  For example, if the PDF is the result
             of a search request you might want to highlight the word in the resulting PDF document.  There are several ways
             this can be achieved, each method varying in complexity and flexibility.
         </p>
         <section>
           <title>1. Use the 'search' open parameter</title>
           <p>
           Acrobat supports passing is various parameters that tell it what to do once the PDF is open.
           See <a href="http://partners.adobe.com/public/developer/en/acrobat/PDFOpenParameters.pdf" target="_blank">PDF Open Parameters</a> for
           documentation on all the open parameters.  One of the parameters is the 'search' parameter, this will automatically run the search
           functionality inside of Acrobat once the PDF is open.  For example: <a href='http://www.pdfbox.org/userguide/text_extraction.pdf#search="check"' target='_blank'>http://www.pdfbox.org/userguide/text_extraction.pdf#search="check"</a><br/>
           <br/>
           <note>The words must be enclosed in quotes and separated by spaces; for example:#search="pdfbox rocks"</note>
           This is a great solution because of its simplicity!  It doesn't require PDFBox at all, but it is a potential solution that
           many developers are not aware of.
           </p>

         </section>
         <section>
           <title>2. Generate a highlight XML document</title>
           <p>
           Acrobat also allows you to tell it to highlight specific words in the PDF document.  It does this by passing an XML document to
           Acrobat when opening the PDF.
           See the <a href="http://partners.adobe.com/public/developer/en/pdf/HighlightFileFormat.pdf" target="_blank">PDF Highlight File Format</a>
           for more detailed documentation.  <br/>
           <br/>
           Basically the document allows you to tell it the characters to highlight in the PDF by using character
           offsets on a page.  As this is just an XML document, there are many ways you could create it but PDFBox does have a utility to make it
           easier.  Take a look at the javadoc for the <a href="/javadoc/org/pdfbox/util/PDFHighlighter.html">PDFHighlighter</a> class.  This will
           allow you specify a set of words that you want have highlighted and generate the XML document for you.  <br/>
           <br/>
           PDFBox also ships with a complete
           web application example of using this class, take a look at the pdfbox.war directory in your PDFBox installation.
           <br/>
           You pass the xml to acrobat through a URL (or command line) parameter like this:
           <a href="http://www.pdfbox.org/userguide/text_extraction.pdf#xml=http://www.pdfbox.org/highlight.xml" target="_blank">http://www.pdfbox.org/userguide/text_extraction.pdf#xml=http://www.pdfbox.org/highlight.xml</a>
           <br/>
           <note>The value of the xml parameter must be a full URL to the XML document.  <br/>
           http://www.pdfbox.org/userguide/text_extraction.pdf#xml=highlight.xml will not work<br/>
           http://www.pdfbox.org/userguide/text_extraction.pdf#xml=http://www.pdfbox.org/highlight.xml is correct!</note>
           <br/>The one drawback to this solution is that you must parse the PDF and then generate an XML document, which is a time consuming operation.
           </p>
         </section>
         <section>
           <title>3. Alter pdf contents to highlight specific text</title>
           <p>
           Using PDFBox it is possible to regenerate the appearance stream to add highlighting to specific areas.  While this is possible,
           it will require recreating a new PDF for every search request.  There is nothing prebuilt in PDFBox to do this automatically for you
           and will require a significant coding effort.<br/>
           <br/>
           You would need to
           <ol>
             <li>Find all locations of the text, determine x/y coordinates, width/height</li>
             <li>Regenerate the PDF appearance stream and draw a highlighted box behind the text.  Yellow would be easiest, if you want an inverted black/white, then you would need to change the color of the text to be white and draw a black box.</li>
             <li>Stream the PDF back to the user</li>
           </ol>
           This is the most flexible but is also the most work to implement and is also more resource intensive.
           </p>
         </section>
     </section>
   </body>
 </document>
	<!--
	! Licensed to the Apache Software Foundation (ASF) under one or more
	! contributor license agreements. See the NOTICE file distributed with
	! 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
	! the License. You may obtain a copy of the License at
	!
	! http://www.apache.org/licenses/LICENSE-2.0
	!
	! Unless required by applicable law or agreed to in writing, software
	! distributed under the License is distributed on an "AS IS" BASIS,
	! WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	! See the License for the specific language governing permissions and
	! limitations under the License.
	!-->
	<!DOCTYPE document PUBLIC "-//APACHE//DTD Documentation V2.0//EN" "http://forrest.apache.org/dtd/document-v20.dtd">
	<document>
	<header>
	<title>PDFBox - PDF Highlighting</title>
	<meta name="keywords">Java PDF Library, highlight, highlight pdf, highlight pdf text, java</meta>
	</header>
	<body>
	<section>
	<title>Highlighting text in a PDF</title>
	<p>
	There are cases when you might want to highlight text in a PDF document. For example, if the PDF is the result
	of a search request you might want to highlight the word in the resulting PDF document. There are several ways
	this can be achieved, each method varying in complexity and flexibility.
	</p>
	<section>
	<title>1. Use the 'search' open parameter</title>
	<p>
	Acrobat supports passing is various parameters that tell it what to do once the PDF is open.
	See <a href="http://partners.adobe.com/public/developer/en/acrobat/PDFOpenParameters.pdf" target="_blank">PDF Open Parameters</a> for
	documentation on all the open parameters. One of the parameters is the 'search' parameter, this will automatically run the search
	functionality inside of Acrobat once the PDF is open. For example: <a href='http://www.pdfbox.org/userguide/text_extraction.pdf#search="check"' target='_blank'>http://www.pdfbox.org/userguide/text_extraction.pdf#search="check"</a><br/>
	<br/>
	<note>The words must be enclosed in quotes and separated by spaces; for example:#search="pdfbox rocks"</note>
	This is a great solution because of its simplicity! It doesn't require PDFBox at all, but it is a potential solution that
	many developers are not aware of.
	</p>

	</section>
	<section>
	<title>2. Generate a highlight XML document</title>
	<p>
	Acrobat also allows you to tell it to highlight specific words in the PDF document. It does this by passing an XML document to
	Acrobat when opening the PDF.
	See the <a href="http://partners.adobe.com/public/developer/en/pdf/HighlightFileFormat.pdf" target="_blank">PDF Highlight File Format</a>
	for more detailed documentation. <br/>
	<br/>
	Basically the document allows you to tell it the characters to highlight in the PDF by using character
	offsets on a page. As this is just an XML document, there are many ways you could create it but PDFBox does have a utility to make it
	easier. Take a look at the javadoc for the <a href="/javadoc/org/pdfbox/util/PDFHighlighter.html">PDFHighlighter</a> class. This will
	allow you specify a set of words that you want have highlighted and generate the XML document for you. <br/>
	<br/>
	PDFBox also ships with a complete
	web application example of using this class, take a look at the pdfbox.war directory in your PDFBox installation.
	<br/>
	You pass the xml to acrobat through a URL (or command line) parameter like this:
	<a href="http://www.pdfbox.org/userguide/text_extraction.pdf#xml=http://www.pdfbox.org/highlight.xml" target="_blank">http://www.pdfbox.org/userguide/text_extraction.pdf#xml=http://www.pdfbox.org/highlight.xml</a>
	<br/>
	<note>The value of the xml parameter must be a full URL to the XML document. <br/>
	http://www.pdfbox.org/userguide/text_extraction.pdf#xml=highlight.xml will not work<br/>
	http://www.pdfbox.org/userguide/text_extraction.pdf#xml=http://www.pdfbox.org/highlight.xml is correct!</note>
	<br/>The one drawback to this solution is that you must parse the PDF and then generate an XML document, which is a time consuming operation.
	</p>
	</section>
	<section>
	<title>3. Alter pdf contents to highlight specific text</title>
	<p>
	Using PDFBox it is possible to regenerate the appearance stream to add highlighting to specific areas. While this is possible,
	it will require recreating a new PDF for every search request. There is nothing prebuilt in PDFBox to do this automatically for you
	and will require a significant coding effort.<br/>
	<br/>
	You would need to
	<ol>
	<li>Find all locations of the text, determine x/y coordinates, width/height</li>
	<li>Regenerate the PDF appearance stream and draw a highlighted box behind the text. Yellow would be easiest, if you want an inverted black/white, then you would need to change the color of the text to be white and draw a black box.</li>
	<li>Stream the PDF back to the user</li>
	</ol>
	This is the most flexible but is also the most work to implement and is also more resource intensive.
	</p>
	</section>
	</section>
	</body>
	</document>