The explain api computes a score explanation for a query and a specific document. This can give useful feedback whether a document matches or didn’t match a specific query.
ExplainRequest expects an
type and an
id to specify a certain document,
and a query represented by
QueryBuilder to run against it (the way of building queries).
ExplainRequest request = new ExplainRequest("contributors", "doc", "1"); request.query(QueryBuilders.termQuery("user", "tanguy"));
Use the preference parameter e.g. to execute the search to prefer local shards. The default is to randomize across shards.
Set to true to retrieve the _source of the document explained. You can also retrieve part of the document by using _source_include & _source_exclude (see Get API for more details)
explain method executes the request synchronously:
ExplainResponse response = client.explain(request, RequestOptions.DEFAULT);
explainAsync method executes the request asynchronously,
calling the provided
ActionListener when the response is ready:
The asynchronous method does not block and returns immediately. Once the request
ActionListener is called back using the
if the execution successfully completed or using the
onFailure method if
A typical listener for
ExplainResponse is constructed as follows:
ExplainResponse contains the following information:
String index = response.getIndex(); String type = response.getType(); String id = response.getId(); boolean exists = response.isExists(); boolean match = response.isMatch(); boolean hasExplanation = response.hasExplanation(); Explanation explanation = response.getExplanation(); GetResult getResult = response.getGetResult();
The index name of the explained document.
The type name of the explained document.
The id of the explained document.
Indicates whether or not the explained document exists.
Indicates whether or not there is a match between the explained document and
the provided query (the
Indicates whether or not there exists a lucene
Get the lucene
GetResult contains two maps internally to store the fetched
_source and stored fields.
You can use the following methods to get them: