[ElasticSearch] An example of using SetFetchSource

The SetFetchSource is a new feature of ElasticSearch1.1. This is a example of how to use it:

String [] excludes = {"field0"};
String [] includes = {"field1","field2"};

SearchResponse searcher = client.getClient().prepareSearch(INDEX).setFetchSource(includes, excludes).setQuery(qb).execute().actionGet();

If you do not include the "addFields()" command, you will not be able to iterate over the fields of the hits. However, you can iterate using "sourceAsMap()".


for (SearchHit hit : searcher.getHits().getHits()) {
    Map hits = hit.sourceAsMap();

    for (String key : hits.keySet()) {
        //do something
    }

    Object [] fieldValues = hits.values().toArray();

    for (Object fieldValue:fieldValues) {
        //do something
    }
}

As you will notice, the excluded fields at "excludes" will not show up. Also, if you try "hit.getFields()" it will be empty.



References:

http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/mapping-source-field.html

https://github.com/elasticsearch/elasticsearch/blob/master/src/test/java/org/elasticsearch/search/source/SourceFetchingTests.java