I have the WordCount MapReduce example in Eclipse. I exported it to Jar, and copied it to S3. I then ran it on AWS-EMR. Successfully.
Then, I read this article - http://docs.aws.amazon.com/ElasticMapReduce/latest/DeveloperGuide/emr-common-programming-sample.html It shows how to use AWS-EMR Api to run MapReduce jobs. It still assumes your MapReduce code is packaged in a Jar.
I would like to know if there is a way to run MapReduce code from Eclipse directly on AWS-EMR, without having to export it to a Jar.