[AWS JasperReports with Redis Sessions]

Is there a way to connect the JasperReports v6 server sessions to AWS Elasticache (Redis).  I have downloaded and installed in the /usr/share/tomcat7/lib directory the following jar files:

 wget -c http://central.maven.org/maven2/redis/clients/jedis/2.5.2/jedis-2.5.2.jar

 wget -c https://github.com/rmohr/tomcat-redis-session-manager/releases/download/2.0-tomcat-7/tomcat-redis-session-manager-2.0.0.jar 

 wget -c http://central.maven.org/maven2/org/apache/commons/commons-pool2/2.2/commons-pool2-2.2.jar

and then change the /usr/share/tomcat7/conf/context.xml to have:

<Context>

...

 <Valve className="com.orangefunction.tomcat.redissessions.RedisSessionHandlerValve" />
 <Manager className="com.orangefunction.tomcat.redissessions.RedisSessionManager"
         host="redis.cache.hostname"
         port="6379"
         database="0"
         maxInactiveInterval="60"
 />

</Context>

But when we try to login the /var/log/jasperreports/jasperreports.log file show:

2018-01-19 15:41:20,881 ERROR SystemErrorController,http-bio-80-exec-11:81 - Internal server error
java.lang.NullPointerException
        at com.orangefunction.tomcat.redissessions.RedisSessionHandlerValve.invoke(RedisSessionHandlerValve.java:28)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:103)
        at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:962)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
        at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1115)
        at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
        at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:316)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1152)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:622)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:748)

and it show a server error.

Is there a doc or HOWTO that you can point me to.