How to use Java to query documents saved in couchdb using elasticsearch?

I want to get some document saved in couchdb using elasticsearch.

I see that the elasticsearch river maybe a choice. Could anyone tell me how to write equivalent java code like following? Given some simple java example, I can gradually work on it. But I am currently stuck on it. Thanks a lot for replying in advance!

curl-XPUT'localhost:9200/_river/my_river/_meta' -d'{
"type" : "dummy"