Java Host Server Usage

Sometime back I was under the impression that the Java Host server is only used for displaying Charts,Graphs and all those flashy images, but, after the below incident I found one more usage of the Java Host server.
Today, I had a requirement to create some reports in BI Publisher. When I logged in to OBIEE and tried to access BI Publisher from More Products then I got the below error:
“An error occurred during execution of “connect“. No connection could be made because the target machine actively refused it”
I was amazed when I got this idiotic error as I just did a fresh OBIEE install. Another interesting thing was that I was able to access the BI Publisher Standalone application and was able to login into the application successfully.
When I read the error, it said ‘target machine refused to connect’ which meant the server is shut down but that was not the case as I was able to login in standalone application. So, this thing brought up more confusions.
After all this confusion, I went and checked all the servers and found that except Java Host server all the servers were started. So, just as a trial I started the Java Host Server and to my surprize my problem got resolved.
I think this post might not be that helpful for some people but it can avoid you from wasting some time.