如何在同一个Java项目中获取mahout和neo4j？

Question

This is part of my pom.xml

<dependency>
    <groupId>org.apache.mahout</groupId>
    <artifactId>mahout-core</artifactId>
    <version>0.9</version>
</dependency>
<dependency>
    <groupId>org.apache.mahout</groupId>
    <artifactId>mahout-math</artifactId>
    <version>0.9</version>
</dependency>
<dependency>
     <groupId>org.neo4j</groupId>
     <artifactId>neo4j</artifactId>
     <version>2.2.1</version>
</dependency>

The ERROR is

Caused by: java.lang.ClassNotFoundException: org.apache.lucene.document.Fieldable
      at java.net.URLClassLoader.findClass(URLClassLoader.java:381)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:424)
      at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:331)
      at java.lang.ClassLoader.loadClass(ClassLoader.java:357)

I found the mahout needs lucene-core 4.6.1, but the neo4j using neo4j-lucene-index 2.2.1, what can I do to solve this problem?

Answer 1

It's common problem. Neo4j 2.3 uses old version of the Lucene (3.6.2). In JVM you aren't able to use two different version of same library.

You have few options how to deal with it, but you should not use them in the production.

1. Create your own Class Loader.

2. Maven Shade plugin