add semantic search using pg vector and ollama (#18251)

* add semantic search using pg vector and ollama

* remove webflux dependency, use chat client

* update annotations

* remove test containers

* move version number, make lowercase the package name, apply Baeldung code formatter

Author: DragomirAlin

spring-ai-2/docker-compose.yml

@@ -0,0 +1,29 @@
+services:
+  postgres:
+    image: pgvector/pgvector:pg17
+    environment:
+      POSTGRES_DB: vectordb
+      POSTGRES_USER: postgres
+      POSTGRES_PASSWORD: postgres
+    ports:
+      - "5434:5432"
+    healthcheck:
+      test: [ "CMD-SHELL", "pg_isready -U postgres" ]
+      interval: 10s
+      timeout: 5s
+      retries: 5
+
+  ollama:
+    image: ollama/ollama:latest
+    ports:
+      - "11435:11434"
+    volumes:
+      - ollama_data:/root/.ollama
+    healthcheck:
+      test: [ "CMD", "curl", "-f", "http://localhost:11435/api/health" ]
+      interval: 10s
+      timeout: 5s
+      retries: 10
+
+volumes:
+  ollama_data:

spring-ai-2/pom.xml

@@ -84,6 +84,10 @@
            <artifactId>hsqldb</artifactId>
            <scope>runtime</scope>
        </dependency>
+       <dependency>
+           <groupId>org.springframework.ai</groupId>
+           <artifactId>spring-ai-pgvector-store-spring-boot-starter</artifactId>
+       </dependency>
 
        <!-- Test dependencies -->
        <dependency>
@@ -106,6 +110,11 @@
            <artifactId>ollama</artifactId>
            <scope>test</scope>
        </dependency>
+       <dependency>
+           <groupId>org.springframework.boot</groupId>
+           <artifactId>spring-boot-docker-compose</artifactId>
+           <version>${spring-boot-docker-compose.version}</version>
+       </dependency>
    </dependencies>
 
    <build>
@@ -131,6 +140,7 @@
        <spring-boot.version>3.4.1</spring-boot.version>
        <spring-ai.version>1.0.0-M6</spring-ai.version>
        <junit-jupiter.version>5.9.0</junit-jupiter.version>
+       <spring-boot-docker-compose.version>3.1.1</spring-boot-docker-compose.version>
    </properties>
 
 </project>

spring-ai-2/src/main/java/com/baeldung/springai/semanticsearch/Application.java

@@ -0,0 +1,26 @@
+package com.baeldung.springai.semanticsearch;
+
+import org.springframework.ai.autoconfigure.openai.OpenAiAutoConfiguration;
+import org.springframework.ai.autoconfigure.vectorstore.chroma.ChromaVectorStoreAutoConfiguration;
+import org.springframework.ai.chat.model.ChatModel;
+import org.springframework.ai.ollama.OllamaChatModel;
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+import org.springframework.context.annotation.Bean;
+import org.springframework.context.annotation.Primary;
+import org.springframework.context.annotation.PropertySource;
+
+@SpringBootApplication(exclude = { OpenAiAutoConfiguration.class, ChromaVectorStoreAutoConfiguration.class })
+@PropertySource("classpath:application-semantic-search.properties")
+public class Application {
+
+    public static void main(String[] args) {
+        SpringApplication.run(Application.class, args);
+    }
+
+    @Bean
+    @Primary
+    public ChatModel chatModel(OllamaChatModel ollamaChatModel) {
+        return ollamaChatModel;
+    }
+}

spring-ai-2/src/main/java/com/baeldung/springai/semanticsearch/Book.java

@@ -0,0 +1,5 @@
+package com.baeldung.springai.semanticsearch;
+
+public record Book(String title, String author, String description) {
+
+}

spring-ai-2/src/main/java/com/baeldung/springai/semanticsearch/BookSearchController.java

@@ -0,0 +1,54 @@
+package com.baeldung.springai.semanticsearch;
+
+import org.springframework.ai.chat.client.ChatClient;
+import org.springframework.ai.document.Document;
+import org.springframework.ai.vectorstore.SearchRequest;
+import org.springframework.ai.vectorstore.VectorStore;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestBody;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+@RequestMapping("/books")
+public class BookSearchController {
+
+    private final VectorStore vectorStore;
+    private final ChatClient chatClient;
+
+    public BookSearchController(VectorStore vectorStore, ChatClient.Builder chatClientBuilder) {
+        this.vectorStore = vectorStore;
+        this.chatClient = chatClientBuilder.build();
+    }
+
+    @PostMapping("/search")
+    List<String> semanticSearch(@RequestBody String query) {
+        return vectorStore.similaritySearch(SearchRequest.builder()
+                .query(query)
+                .topK(3)
+                .build())
+            .stream()
+            .map(Document::getText)
+            .toList();
+    }
+
+    @PostMapping("/enhanced-search")
+    String enhancedSearch(@RequestBody String query) {
+        String context = vectorStore.similaritySearch(SearchRequest.builder()
+                .query(query)
+                .topK(3)
+                .build())
+            .stream()
+            .map(Document::getText)
+            .reduce("", (a, b) -> a + b + "\n");
+
+        return chatClient.prompt()
+            .system(context)
+            .user(query)
+            .call()
+            .content();
+    }
+
+}

spring-ai-2/src/main/java/com/baeldung/springai/semanticsearch/BooksIngestionPipeline.java

@@ -0,0 +1,39 @@
+package com.baeldung.springai.semanticsearch;
+
+import jakarta.annotation.PostConstruct;
+
+import org.springframework.ai.document.Document;
+import org.springframework.ai.vectorstore.VectorStore;
+import org.springframework.stereotype.Component;
+
+import java.util.List;
+
+@Component
+public class BooksIngestionPipeline {
+
+    private final VectorStore vectorStore;
+
+    public BooksIngestionPipeline(VectorStore vectorStore) {
+        this.vectorStore = vectorStore;
+    }
+
+    @PostConstruct
+    void run() {
+        var books = List.of(new Book("The Great Gatsby", "F. Scott Fitzgerald",
+                "The Great Gatsby is a 1925 novel by American writer F. Scott Fitzgerald. Set in the Jazz Age on Long Island, near New York City, the novel depicts first-person narrator Nick Carraway's interactions with mysterious millionaire Jay Gatsby and Gatsby's obsession to reunite with his former lover, Daisy Buchanan."),
+            new Book("To Kill a Mockingbird", "Harper Lee",
+                "To Kill a Mockingbird is a novel by the American author Harper Lee. It was published in 1960 and was instantly successful. In the United States, it is widely read in high schools and middle schools."),
+            new Book("1984", "George Orwell",
+                "Nineteen Eighty-Four: A Novel, often referred to as 1984, is a dystopian social science fiction novel by the English novelist George Orwell. It was published on 8 June 1949 by Secker & Warburg as Orwell's ninth and final book completed in his lifetime."),
+            new Book("The Catcher in the Rye", "J. D. Salinger",
+                "The Catcher in the Rye is a novel by J. D. Salinger, partially published in serial form in 1945–1946 and as a novel in 1951. It was originally intended for adults but is often read by adolescents for its themes of angst, alienation, and as a critique on superficiality in society."),
+            new Book("Lord of the Flies", "William Golding",
+                "Lord of the Flies is a 1954 novel by Nobel Prize-winning British author William Golding. The book focuses on a group of British"));
+
+        List<Document> documents = books.stream()
+            .map(book -> new Document(book.toString()))
+            .toList();
+
+        vectorStore.add(documents);
+    }
+}

spring-ai-2/src/main/resources/application-semantic-search.properties

@@ -0,0 +1,13 @@
+spring.ai.ollama.init.pull-model-strategy=when_missing
+spring.ai.ollama.init.chat.include=true
+spring.ai.ollama.embedding.options.model=nomic-embed-text
+spring.ai.vectorstore.pgvector.initialize-schema=true
+spring.ai.vectorstore.pgvector.dimensions=768
+spring.ai.vectorstore.pgvector.index-type=hnsw
+spring.docker.compose.file=docker-compose.yml
+spring.docker.compose.enabled=true
+spring.datasource.url=jdbc:postgresql://localhost:5434/vectordb
+spring.datasource.username=postgres
+spring.datasource.password=postgres
+spring.datasource.driver-class-name=org.postgresql.Driver
+spring.jpa.database-platform=org.hibernate.dialect.PostgreSQLDialect