various additions

Author: vga91

modules/genai-ecosystem/pages/langchain4j.adoc

@@ -40,24 +40,80 @@ An example is avalable at: https://github.com/langchain4j/langchain4j-examples/t
 include::https://github.com/langchain4j/langchain4j-examples/raw/main/neo4j-example/src/main/java/Neo4jEmbeddingStoreExample.java[]
 ----
 
-=== Usage Examples
-
 To create a Neo4jEmbeddingStore, we can write:
 [source,java]
 ----
 Neo4jEmbeddingStore embeddingStore = Neo4jEmbeddingStore.builder().<builderParameters>.build();
 
-// where <builderParameters> can be the following:
-.dimension(384)
-.label(LABEL_TO_SANITIZE)
-.build();
+
 
 // we can use with `withBasicAuth`
 .withBasicAuth(neo4jContainer.getBoltUrl(), USERNAME, ADMIN_PASSWORD)
 // as alternative to driver:
 Driver driver = GraphDatabase.driver(neo4jContainer.getBoltUrl(), AuthTokens.basic(USERNAME, ADMIN_PASSWORD));
 ----
 
+Where `<builderParameters>` must have `dimension` and either `driver` or `withBasicAuth` parameters,
+besides other optional ones.
+
+Here is the complete builder list:
+
+[options="header",cols="m,m,a"]
+|===
+| Key  | Default Value | Description
+| driver | <required if withBasicAuth is not set> | the https://neo4j.com/docs/api/java-driver/current/org.neo4j.driver/org/neo4j/driver/Driver.html[Java Driver instance]
+| withBasicAuth | <required if withBasicAuth is not set> | Creates an instance of Neo4jEmbeddingStore defining a https://neo4j.com/docs/api/java-driver/current/org.neo4j.driver/org/neo4j/driver/Driver.html[Java Driver instance], starting from `uri`, `user` and `password`
+| dimension | <required> | the vector's dimension
+| config | org.neo4j.driver.SessionConfig.forDatabase(`<databaseName>`) | the https://neo4j.com/docs/api/java-driver/current/org.neo4j.driver/org/neo4j/driver/SessionConfig.html[SessionConfig instance]
+| label | "Document" | the label name 
+| embeddingProperty | "embedding" | the embedding property name 
+| idProperty | "id" | the id property name
+| metadataPrefix | "" | the metadata prefix 
+| textProperty | "text" | the text property name
+| indexName | "vector" | the vector index name
+| databaseName | "neo4j" | the database name
+| retrievalQuery | "RETURN properties(node) AS metadata, node.`idProperty` AS `idProperty`, node.`textProperty` AS `textProperty`, node.`embeddingProperty` AS `embeddingProperty`, score" | the retrieval query
+|===
+
+=== Usage Examples
+
+LangChain4j provides the following classes for Neo4j integration:
+- `Neo4jEmbeddingStore`: Implements the EmbeddingStore interface, enabling storing and querying vector embeddings in a Neo4j database.
+- `Neo4jText2CypherRetriever`: Supports retrieving original content associated with stored embeddings.
+
+==== Neo4jEmbeddingStore
+
+We can define an `Neo4jEmbeddingStore` with the required Java Driver instance and dimension and an optional label name in this way:
+
+[source,java]
+----
+Driver driver = GraphDatabase.driver('<boltURL>', AuthTokens.basic('<username>', '<password>'));
+
+Neo4jEmbeddingStore embeddingStore = Neo4jEmbeddingStore.builder()
+    .withDriver(driver)
+    .dimension(384)
+    .label("CustomLabel")
+    .build();
+----
+
+We can use `withBasicAuth` as an alternative to `driver` creation:
+[source,java]
+----
+Neo4jEmbeddingStore embeddingStore = Neo4jEmbeddingStore.builder()
+    .withBasicAuth('<boltURL>', '<username>', '<password>')
+    .<otherBuilderParameters>
+    .build();
+
+/* instead of 
+    Driver driver = GraphDatabase.driver('<boltURL>', AuthTokens.basic('<username>', '<password>'));
+    Neo4jEmbeddingStore embeddingStore = Neo4jEmbeddingStore.builder()
+        .withDriver(driver)
+        .<otherBuilderParameters>
+        .build()
+*/
+ 
+----
+
 To add embeddings, execute:
 [source,java]
 ----
@@ -84,7 +140,7 @@ String id = embeddingStore.add(embedding, segment);
 // output: id of the embedding
 ----
 
-Too add embeddings with segment and metadata:
+To add embeddings with segment and metadata:
 [source,java]
 ----
 TextSegment segment = TextSegment.from(randomUUID(), Metadata.from(METADATA_KEY, "test-value"));
@@ -106,7 +162,8 @@ final List<EmbeddingMatch<TextSegment>> relevant = embeddingStore.search(request
 // output: list of embeddings
 ----
 
-Search embeddings with minScore:
+To search embeddings with `minScore`:
+
 [source,java]
 ----
 Embedding embedding = embeddingModel.embed("embedText").content();
@@ -120,12 +177,13 @@ final List<EmbeddingMatch<TextSegment>> relevant = embeddingStore.search(request
 // output: list of embeddings
 ----
 
-Search embeddings with segment with custom metadata prefix:
+To search embeddings with segment with custom metadata prefix:
 [source,java]
 ----
 String metadataPrefix = "metadata.";
 String labelName = "CustomLabelName";
-embeddingStore = Neo4jEmbeddingStore.builder()
+
+Neo4jEmbeddingStore embeddingStore = Neo4jEmbeddingStore.builder()
         .withBasicAuth(neo4jContainer.getBoltUrl(), USERNAME, ADMIN_PASSWORD)
         .dimension(384)
         .metadataPrefix(metadataPrefix)
@@ -154,7 +212,7 @@ Search embeddings with segment with metadata and custom id prop:
 String metadataPrefix = "metadata.";
 String customIdProp = "customId ` & Prop ` To Sanitize";
 
-embeddingStore = Neo4jEmbeddingStore.builder()
+Neo4jEmbeddingStore embeddingStore = Neo4jEmbeddingStore.builder()
         .withBasicAuth(neo4jContainer.getBoltUrl(), USERNAME, ADMIN_PASSWORD)
         .dimension(384)
         .metadataPrefix(metadataPrefix)
@@ -215,6 +273,25 @@ final List<EmbeddingMatch<TextSegment>> relevant = embeddingStore.search(request
 // output: list of embeddings
 ----
 
+==== Neo4jText2CypherRetriever
+[source,java]
+----
+// create dataset
+// CREATE (book:Book {title: 'Dune'})<-[:WROTE]-(author:Person {name: 'Frank Herbert'})");
+Neo4jText2CypherRetriever retriever = Neo4jText2CypherRetriever.builder()
+        .graph(graph)
+        .chatLanguageModel(chatLanguageModel)
+        .build();
+
+Query query = new Query("Who is the author of the book 'Dune'?");
+
+List<Content> contents = retriever.retrieve(query);
+
+System.out.println(contents.get(0).textSegment().text()); 
+// output: "Frank Herbert"
+----
+
+
 == Relevant Links
 [cols="1,4"]
 |===