Submit MR with JAR not by terminal

Hi,
I am new to hortonworks and trying to study how to do MapReduce, but I don’t want to do it using terminal commands.
I want to write external java program to run the MR jar.
I looked here:
Cluster_Applications_API(Submit_Application)
I see there is a need to get a new application id:
luster_New_Application_API
But when I use what they say: “http://[host ip]:[port=8088]/ws/v1/cluster/apps/new-application”
I get exception:
<RemoteException>
<exception>WebApplicationException</exception>
<javaClassName>javax.ws.rs.WebApplicationException</javaClassName>
</RemoteException>

Am I missing something?
Does anyone have a REST example code for submitting and monitoring MR jobs?

Thanks!