PLMultiAnalyzer

A Lucene custom analyzer that allow for indexing multiple tokens for a single term it supports storing terms with Mixed-case letters and terms with punctuation. This in theory should produce more accurate results as it causes Lucene to perform a more exact search.

Released under the MIT License.

Adding a Custom analyzer to exist-db

1.Building eXist-db

$ git clone https://github.com/eXist-db/exist.git
$ cd exist
$ git checkout master
$ mvn -DskipTests package

we will refer to the exist-db directory as $EXIST_HOME you can set it using Linux/macOS:

$ export EXIST_HOME=/your/path/to/eXist-db

Windows:

$ set EXIST_HOME=C:\your\path\to\eXist-db

Copy the Jar into exist-db directory

Linux/macOS:

$ cp PLMultiAnalyzer-1.0.0-SNAPSHOT.jar  $EXIST_HOME/exist-distribution/target/exist-distribution-[version]-dir/lib

Windows:

$ copy PLMultiAnalyzer-1.0.0-SNAPSHOT.jar  %EXIST_HOME%\exist-distribution\target\exist-distribution-[version]-dir\lib

Add the analyzer dependency in exist start up script

in your $EXIST_HOME/exist-distribution/target/exist-distribution-[version]-dir/etc/startup.xml add to the dependencies

<dependencies>
    ... <!-- other dependencies -->
    <dependency>
        <groupId>com.evolvedbinary.lucene.analyzer</groupId>
        <artifactId>ohAnalyzer</artifactId> 
        <version>1.0.0-SNAPSHOT</version>
        <relativePath>PLMultiAnalyzer-1.0.0-SNAPSHOT.jar</relativePath> <!-- must be exact match to the jar in lib folder -->
    </dependency>
    ... <!-- other dependencies -->
<dependencies>

Start up exist

run the start up script Linux/macOS:

$ $EXIST_HOME/exist-distribution/target/exist-distribution-[version]-dir/bin/startup.sh

Windows:

$ %EXIST_HOME%\exist-distribution\target\exist-distribution-[version]-dir\bin\startup.bat

Index The data using the custom Analyzer

when creating the index config specify the Analyzer as com.evolvedbinary.lucene.analyzer.OhAnalyzer the Analyzer needs two parameters

• minimumTermLength: the minimum length of any decomposed term, any smaller decomposed terms will be discarded. Set to 0 to indicate no minimum.
• punctuationDictionary: the dictionary of punctuation to use for decomposition.

<collection xmlns="http://exist-db.org/collection-config/1.0">
    <index xmlns:wiki="http://exist-db.org/xquery/wiki" xmlns:html="http://www.w3.org/1999/xhtml" xmlns:atom="http://www.w3.org/2005/Atom">
        <!-- Lucene index is configured below -->
        <lucene>
	        <analyzer class="com.evolvedbinary.lucene.analyzer.OhAnalyzer">
                <param name="punctuationDictionary" type="char[]">
                    <value>'</value>
                    <value>-</value>
                    <value>’</value>
                </param>
                <param name="minimumTermLength" type="int" value="2" />
            <analyzer>
	        <text qname="doc"/>
        </lucene>
    </index>
</collection>