Alternative IndexProvider for Neo4J 1.9.1

Question

I'm using Lucene 4 in my application and don't want to change this. I'm trying to integrate Neo4J which bundles Lucene 3.5 as an IndexProvider implementation, neo4j-lucene-index.

Unfortunately, neo4j-lucene-index does not work, and with that dependency excluded, the app just hangs indefinitely on start up. I've tried neo4j-lucene4-index but that does not seem to be maintained very well and needs to be updated quite significantly to work with Neo4J 1.9.1. The changes go way beyond my understanding of the internals of Neo4J.

However, I can see that IndexProviders are pluggable, so I'm hoping that there is an existing alternative to Lucene - I can't find it at the moment though. Can anyone point me in the right direction for one?

It seems strange that Lucene 4 has been out for so long now and Neo4J doesn't support it. Am I missing something?

Currently, my POM looks like this for my Neo4J config:

<dependency>
    <groupId>org.springframework.data</groupId>
    <artifactId>spring-data-neo4j</artifactId>
    <version>2.2.1.RELEASE</version>
    <exclusions>
        <exclusion>
        <artifactId>neo4j</artifactId>
        <groupId>org.neo4j</groupId>
        </exclusion>
        <exclusion>
        <artifactId>neo4j-cypher</artifactId>
        <groupId>org.neo4j</groupId>
        </exclusion>
    </exclusions>
</dependency>
<dependency>
    <groupId>org.neo4j</groupId>
    <artifactId>neo4j-kernel</artifactId>
    <version>1.9.1</version>
    <exclusion>
        <groupId>org.neo4j</groupId>
        <artifactId>neo4j-lucene-index</artifactId>
    </exclusion>
</dependency>

<dependency>
    <groupId>org.neo4j.app</groupId>
    <artifactId>neo4j-server</artifactId>
    <version>1.9.1</version>
    <exclusions>
        <exclusion>
        <artifactId>neo4j</artifactId>
        <groupId>org.neo4j</groupId>
        </exclusion>
        <exclusion>
        <artifactId>neo4j-cypher</artifactId>
        <groupId>org.neo4j</groupId>
        </exclusion>
        <exclusion>
        <groupId>org.neo4j</groupId>
        <artifactId>neo4j-lucene-index</artifactId>
        </exclusion>
    </exclusions>
</dependency>

    <!-- A temporary dependency until Neo4J builds in support for Lucene 4. 
    Looks like they're planning to incorporate this project anyway This project 
    is available on GitHub, and needs to be built with: mvn license:format mvn 
    install to install into your local repo. 
        <dependency>
            <groupId>com.keatext</groupId>
            <artifactId>neo4j-lucene4-index</artifactId>
            <version>1.9.M01-SNAPSHOT</version>
        </dependency>-->

<dependency>
    <groupId>org.hibernate</groupId>
    <artifactId>hibernate-validator</artifactId>
    <version>5.0.1.Final</version>
</dependency>

Answer 1

There have been some changes internally from 1.8 -> 1.9. In short, a index provider must register a KernelExtensionFactory via META-INF/services, see https://github.com/neo4j/neo4j/blob/master/community/lucene-index/src/main/resources/META-INF/services/org.neo4j.kernel.extension.KernelExtensionFactory

This KernelExtensionFactory is the entry point, just checkout the Lucene 3 based implementation at https://github.com/neo4j/neo4j/tree/master/community/lucene-index.