The extension must consist of a single JAR file. If you have dependencies other than the libraries provided by the DataCleaner distribution, you need to package these inside your own JAR file. If you're using Maven for your build, the Maven Assembly Plugin can provide this functionality easily using this snippet in your POM:

			<build>
			 <plugins>
			  <plugin>
			   <groupId>org.apache.maven.plugins</groupId>
			   <artifactId>maven-assembly-plugin</artifactId>
			   <version>2.2.1</version>
			   <configuration>
			    <descriptorRefs>
			     <descriptorRef>jar-with-dependencies</descriptorRef>
			    </descriptorRefs>
			   </configuration>
			  </plugin>
			 </plugins>
			</build>