Interface ContentRetriever

All Known Implementing Classes:

AzureAiSearchContentRetriever, AzureCosmosDBNoSqlContentRetriever, ElasticsearchContentRetriever, EmbeddingStoreContentRetriever, SqlDatabaseContentRetriever, WebSearchContentRetriever

public interface ContentRetriever

Retrieves Contents from an underlying data source using a given Query.
The goal is to retrieve only relevant Contents in relation to a given Query.
The underlying data source can be virtually anything:

- Embedding (vector) store (see EmbeddingStoreContentRetriever)
- Full-text search engine (see AzureAiSearchContentRetriever in the langchain4j-azure-ai-search module)
- Hybrid of vector and full-text search (see AzureAiSearchContentRetriever in the langchain4j-azure-ai-search module)
- Web Search Engine (see WebSearchContentRetriever)
- Knowledge graph (see Neo4jContentRetriever in the langchain4j-community-neo4j-retriever module)
- SQL database (see SqlDatabaseContentRetriever in the langchain4j-experimental-sql module)
- etc.

See Also:

• EmbeddingStoreContentRetriever
• WebSearchContentRetriever

Method Summary

Modifier and Type	Method	Description
default ContentRetriever	addListener(ContentRetrieverListener listener)	Wraps this ContentRetriever with a listening retriever that dispatches events to the provided listener.
default ContentRetriever	addListeners(Collection<ContentRetrieverListener> listeners)	Wraps this ContentRetriever with a listening retriever that dispatches events to the provided listeners.
List<Content>	retrieve(Query query)	Retrieves relevant Contents using a given Query.

Method Details

retrieve

List<Content> retrieve(Query query)

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>.

Parameters:

query - The Query to use for retrieval.

Returns:

A list of retrieved Contents.

addListener

@Experimental
default ContentRetriever addListener(ContentRetrieverListener listener)

Wraps this ContentRetriever with a listening retriever that dispatches events to the provided listener.

Parameters:

listener - The listener to add.

Returns:

An observing ContentRetriever that will dispatch events to the provided listener.

Since:

1.11.0

addListeners

@Experimental
default ContentRetriever addListeners(Collection<ContentRetrieverListener> listeners)

Wraps this ContentRetriever with a listening retriever that dispatches events to the provided listeners.

Listeners are called in the order of iteration.

Parameters:

listeners - The listeners to add.

Returns:

An observing ContentRetriever that will dispatch events to the provided listeners.

Since:

1.11.0