Elasticsearch: why Java client uses different query syntax? - elasticsearch

Question

I am new to Elasticsearch. I have the following query:
{
"query": {
"filtered" : {
"query" : {
"term" : {
"title" : "crime"
}
},
"filter" : {
"term" : { "year" : 1961 }
}
}
}
}
It runs fine under Windows prompt as follows:
curl -XGET localhost:9200/book/_search?pretty -d #my-query.json
For the same query with Java client, I have the following:
SearchResponse sr = client.prepareSearch("book")
.setTypes("fiction")
.setQuery(query_string)
.setFrom(page)
.setSize(10).execute().actionGet();
However, I have to the following query string in order to run it without exception:
{
"filtered" : {
"query" : {
"term" : {
"title" : "crime"
}
},
"filter" : {
"term" : { "year" : 1961 }
}
}
}
Why is there such a difference? How can I retain the removed "query" property"? Suppose that I have to use query string in my Java client.
Thanks and regards!

Answer 1

Strictly speaking, the two variants you show are not the same: you don't specify the type, offset, or size parameters in your URI-based query (even though you can do it there too, according to the docs). You can omit these parameters in Java query as well:
SearchResponse sr = client.prepareSearch("book")
.setQuery(query_string)
.execute().actionGet();
Regarding the argument for setQuery, it can be either the same JSON as you have in your URI variant:
String theQuery = String.join(System.getProperty("line.separator"),
"{\"filtered\" : {\"query\" : {\"term\" : {\"title\" : \"crime\"}},",
"\"filter\" : {\"term\" : { \"year\" : 1961 }}}}");
SearchResponse sr = client.prepareSearch("book")
.setTypes("fiction")
.setFrom(page)
.setQuery(queryString(theQuery)).execute().actionGet();
Or you can provide the analog of this query using Java methods:
SearchResponse sr = client.prepareSearch("book")
.setTypes("fiction")
.setFrom(page)
.setQuery(filteredQuery(QueryBuilders.termQuery("title","crime"),
FilterBuilders.termFilter("year","1961")))
.execute().actionGet();