Class ElasticsearchContentRetriever

java.lang.Object

dev.langchain4j.store.embedding.elasticsearch.AbstractElasticsearchEmbeddingStore

dev.langchain4j.rag.content.retriever.elasticsearch.ElasticsearchContentRetriever

All Implemented Interfaces:

ContentRetriever, EmbeddingStore<TextSegment>

public class ElasticsearchContentRetriever
extends AbstractElasticsearchEmbeddingStore
implements ContentRetriever

Represents an Elasticsearch index as a ContentRetriever.

See Also:

• for the exact brute force implementation (slower - 100% accurate)
• for the knn search implementation (faster - approximative)
• for full text search (non vector)
• for hybrid search (semantic and text search combined)
  Supports storing Metadata and filtering by it using Filter (provided inside EmbeddingSearchRequest).

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	ElasticsearchContentRetriever.Builder

Field Summary

Fields inherited from class AbstractElasticsearchEmbeddingStore

client, configuration, indexName

Constructor Summary

Constructors

Constructor	Description
ElasticsearchContentRetriever(ElasticsearchConfiguration configuration, org.elasticsearch.client.RestClient restClient, String indexName, EmbeddingModel embeddingModel, int maxResults, double minScore, Filter filter)	Creates an instance of ElasticsearchContentRetriever using a RestClient.

Method Summary

Modifier and Type	Method	Description
static ElasticsearchContentRetriever.Builder	builder()
List<Content>	retrieve(Query query)	Retrieves relevant Contents using a given Query.

Methods inherited from class AbstractElasticsearchEmbeddingStore

add, add, add, add, add, addAll, addAll, addAllText, fullTextSearch, hybridSearch, initialize, removeAll, removeAll, removeAll, search

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface ContentRetriever

addListener, addListeners

Methods inherited from interface EmbeddingStore

addAll, addListener, addListeners, generateIds, remove

Constructor Details

ElasticsearchContentRetriever

public ElasticsearchContentRetriever(ElasticsearchConfiguration configuration,
 org.elasticsearch.client.RestClient restClient,
 String indexName,
 EmbeddingModel embeddingModel,
 int maxResults,
 double minScore,
 Filter filter)

Creates an instance of ElasticsearchContentRetriever using a RestClient.

Parameters:

configuration - Elasticsearch retriever configuration to use (knn, script, full text, hybrid, hybrid with reranker)

restClient - Elasticsearch Rest Client (mandatory)

indexName - Elasticsearch index name (optional). Default value: "default". Index will be created automatically if not exists.

embeddingModel - Embedding model to be used by the retriever

maxResults - Maximum number of results to retrieve

minScore - Minimum score threshold for retrieved results

filter - Filter to apply during retrieval

Method Details

retrieve

public List<Content> retrieve(Query query)

Description copied from interface: ContentRetriever

Retrieves relevant Contents using a given Query. The Contents are sorted by relevance, with the most relevant Contents appearing at the beginning of the returned List<Content>.

Specified by:

retrieve in interface ContentRetriever

Parameters:

query - The Query to use for retrieval.

Returns:

A list of retrieved Contents.

builder

public static ElasticsearchContentRetriever.Builder builder()