[Feature] Elasticsearch spring boot starter

langchian4j-elasticsearch-spring-boot-starter/pom.xml

@@ -0,0 +1,80 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+    <modelVersion>4.0.0</modelVersion>
+    <parent>
+        <groupId>dev.langchain4j</groupId>
+        <artifactId>langchain4j-spring</artifactId>
+        <version>0.32.0-SNAPSHOT</version>
+        <relativePath>../pom.xml</relativePath>
+    </parent>
+
+    <artifactId>langchian4j-elasticsearch-spring-boot-starter</artifactId>
+    <name>LangChain4j Spring Boot starter for Elasticsearch Vector Store</name>
+    <packaging>jar</packaging>
+
+    <dependencies>
+
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-elasticsearch</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter</artifactId>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-autoconfigure-processor</artifactId>
+            <optional>true</optional>
+        </dependency>
+
+        <!-- should be listed before spring-boot-configuration-processor -->
+        <dependency>
+            <groupId>org.projectlombok</groupId>
+            <artifactId>lombok</artifactId>
+            <scope>provided</scope>
+        </dependency>
+
+        <!-- needed to generate automatic metadata about available config properties -->
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-configuration-processor</artifactId>
+            <optional>true</optional>
+        </dependency>
+
+        <dependency>
+            <groupId>org.springframework.boot</groupId>
+            <artifactId>spring-boot-starter-test</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>dev.langchain4j</groupId>
+            <artifactId>langchain4j-embeddings-all-minilm-l6-v2-q</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.testcontainers</groupId>
+            <artifactId>elasticsearch</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.tinylog</groupId>
+            <artifactId>tinylog-impl</artifactId>
+            <scope>test</scope>
+        </dependency>
+
+        <dependency>
+            <groupId>org.tinylog</groupId>
+            <artifactId>slf4j-tinylog</artifactId>
+            <scope>test</scope>
+        </dependency>
+    </dependencies>
+
+</project>

langchian4j-elasticsearch-spring-boot-starter/src/main/java/dev/langchain4j/store/embedding/elasticsearch/spring/ElasticsearchEmbeddingStoreAutoConfiguration.java

@@ -0,0 +1,39 @@
+package dev.langchain4j.store.embedding.elasticsearch.spring;
+
+import dev.langchain4j.model.embedding.EmbeddingModel;
+import dev.langchain4j.store.embedding.elasticsearch.ElasticsearchEmbeddingStore;
+import org.springframework.boot.autoconfigure.AutoConfiguration;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnMissingBean;
+import org.springframework.boot.autoconfigure.condition.ConditionalOnProperty;
+import org.springframework.boot.context.properties.EnableConfigurationProperties;
+import org.springframework.context.annotation.Bean;
+
+import java.util.Optional;
+
+import static dev.langchain4j.store.embedding.elasticsearch.spring.ElasticsearchEmbeddingStoreProperties.*;
+
+@AutoConfiguration
+@EnableConfigurationProperties(ElasticsearchEmbeddingStoreProperties.class)
+@ConditionalOnProperty(prefix = PREFIX, name = "enabled", havingValue = "true", matchIfMissing = true)
+public class ElasticsearchEmbeddingStoreAutoConfiguration {
+
+    @Bean
+    @ConditionalOnMissingBean
+    @ConditionalOnBean(EmbeddingModel.class)
+    public ElasticsearchEmbeddingStore elasticsearchEmbeddingStore(EmbeddingModel embeddingModel,
+                                                                   ElasticsearchEmbeddingStoreProperties properties) {
+        String serverUrl = Optional.ofNullable(properties.getServerUrl()).orElse(DEFAULT_SERVER_URL);
+        String indexName = Optional.ofNullable(properties.getIndexName()).orElse(DEFAULT_INDEX_NAME);
+        int dimension = Optional.ofNullable(properties.getDimension()).orElse(embeddingModel.dimension());
+
+        return ElasticsearchEmbeddingStore.builder()
+                .serverUrl(serverUrl)
+                .apiKey(properties.getApiKey())
+                .userName(properties.getUserName())
+                .password(properties.getPassword())
+                .indexName(indexName)
+                .dimension(dimension)
+                .build();
+    }
+}

langchian4j-elasticsearch-spring-boot-starter/src/main/java/dev/langchain4j/store/embedding/elasticsearch/spring/ElasticsearchEmbeddingStoreProperties.java

@@ -0,0 +1,22 @@
+package dev.langchain4j.store.embedding.elasticsearch.spring;
+
+import lombok.Getter;
+import lombok.Setter;
+import org.springframework.boot.context.properties.ConfigurationProperties;
+
+@Getter
+@Setter
+@ConfigurationProperties(prefix = ElasticsearchEmbeddingStoreProperties.PREFIX)
+public class ElasticsearchEmbeddingStoreProperties {
+
+    static final String PREFIX = "langchain4j.elasticsearch";
+    static final String DEFAULT_SERVER_URL = "http://localhost:9200";
+    static final String DEFAULT_INDEX_NAME = "langchain4j-index";
+
+    private String serverUrl;
+    private String apiKey;
+    private String userName;
+    private String password;
+    private String indexName;
+    private Integer dimension;
+}

langchian4j-elasticsearch-spring-boot-starter/src/main/resources/META-INF/spring.factories

@@ -0,0 +1 @@
+org.springframework.boot.autoconfigure.EnableAutoConfiguration=dev.langchain4j.store.embedding.elasticsearch.spring.ElasticsearchEmbeddingStoreAutoConfiguration

langchian4j-elasticsearch-spring-boot-starter/src/main/resources/META-INF/spring/org.springframework.boot.autoconfigure.AutoConfiguration.imports

@@ -0,0 +1 @@
+dev.langchain4j.store.embedding.elasticsearch.spring.ElasticsearchEmbeddingStoreAutoConfiguration

langchian4j-elasticsearch-spring-boot-starter/src/test/java/dev/langchain4j/store/embedding/elasticsearch/spring/ElasticsearchEmbeddingStoreAutoConfigurationIT.java

@@ -0,0 +1,80 @@
+package dev.langchain4j.store.embedding.elasticsearch.spring;
+
+import dev.langchain4j.data.embedding.Embedding;
+import dev.langchain4j.data.segment.TextSegment;
+import dev.langchain4j.model.embedding.AllMiniLmL6V2QuantizedEmbeddingModel;
+import dev.langchain4j.model.embedding.EmbeddingModel;
+import dev.langchain4j.store.embedding.EmbeddingMatch;
+import dev.langchain4j.store.embedding.EmbeddingStore;
+import dev.langchain4j.store.embedding.elasticsearch.ElasticsearchEmbeddingStore;
+import lombok.SneakyThrows;
+import org.junit.jupiter.api.AfterAll;
+import org.junit.jupiter.api.BeforeAll;
+import org.junit.jupiter.api.Test;
+import org.springframework.boot.autoconfigure.AutoConfigurations;
+import org.springframework.boot.test.context.runner.ApplicationContextRunner;
+import org.testcontainers.containers.wait.strategy.Wait;
+import org.testcontainers.elasticsearch.ElasticsearchContainer;
+
+import java.util.List;
+
+import static dev.langchain4j.internal.Utils.randomUUID;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.assertj.core.data.Percentage.withPercentage;
+
+class ElasticsearchEmbeddingStoreAutoConfigurationIT {
+
+    static ElasticsearchContainer elasticsearch = new ElasticsearchContainer("elasticsearch:8.9.0")
+            .withEnv("xpack.security.enabled", "false")
+            .waitingFor(Wait.defaultWaitStrategy());
+
+    ApplicationContextRunner contextRunner = new ApplicationContextRunner()
+            .withConfiguration(AutoConfigurations.of(ElasticsearchEmbeddingStoreAutoConfiguration.class));
+
+    @BeforeAll
+    static void beforeAll() {
+        elasticsearch.start();
+    }
+
+    @AfterAll
+    static void afterAll() {
+        elasticsearch.stop();
+    }
+
+    @Test
+    void should_provide_elasticsearch_vector_store() {
+        TextSegment segment = TextSegment.from("hello");
+        contextRunner
+                .withBean(AllMiniLmL6V2QuantizedEmbeddingModel.class)
+                .withPropertyValues(
+                        "langchain4j.elasticsearch.serverUrl=" + elasticsearch.getHttpHostAddress(),
+                        "langchain4j.elasticsearch.indexName=" + randomUUID()
+                )
+                .run(context -> {
+                    EmbeddingModel embeddingModel = context.getBean(AllMiniLmL6V2QuantizedEmbeddingModel.class);
+                    Embedding embedding = embeddingModel.embed(segment.text()).content();
+
+                    EmbeddingStore<TextSegment> embeddingStore = context.getBean(ElasticsearchEmbeddingStore.class);
+                    assertThat(embeddingStore).isInstanceOf(ElasticsearchEmbeddingStore.class);
+
+                    String id = embeddingStore.add(embedding, segment);
+                    assertThat(id).isNotBlank();
+
+                    awaitUntilPersisted();
+
+                    List<EmbeddingMatch<TextSegment>> relevant = embeddingStore.findRelevant(embedding, 10);
+                    assertThat(relevant).hasSize(1);
+
+                    EmbeddingMatch<TextSegment> match = relevant.get(0);
+                    assertThat(match.score()).isCloseTo(1, withPercentage(1));
+                    assertThat(match.embeddingId()).isEqualTo(id);
+                    assertThat(match.embedding()).isEqualTo(embedding);
+                    assertThat(match.embedded()).isEqualTo(segment);
+                });
+    }
+
+    @SneakyThrows
+    private void awaitUntilPersisted() {
+        Thread.sleep(1000);
+    }
+}

pom.xml

@@ -21,18 +21,29 @@
         <module>langchain4j-open-ai-spring-boot-starter</module>
         <module>langchain4j-azure-ai-search-spring-boot-starter</module>
         <module>langchain4j-azure-open-ai-spring-boot-starter</module>
+        <module>langchian4j-elasticsearch-spring-boot-starter</module>
     </modules>
 
     <properties>
         <maven.compiler.source>17</maven.compiler.source>
         <maven.compiler.target>17</maven.compiler.target>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <spring.boot.version>3.2.6</spring.boot.version>
+        <testcontainers.version>1.19.8</testcontainers.version>
+        <tinylog.version>2.6.2</tinylog.version>
     </properties>
 
     <dependencyManagement>
         <dependencies>
 
+            <dependency>
+                <groupId>dev.langchain4j</groupId>
+                <artifactId>langchain4j-bom</artifactId>
+                <version>${project.version}</version>
+                <type>pom</type>
+                <scope>import</scope>
+            </dependency>
+
             <dependency>
                 <groupId>org.springframework.boot</groupId>
                 <artifactId>spring-boot-starter</artifactId>
@@ -63,10 +74,22 @@
                 <version>1.18.32</version>
             </dependency>
 
+            <dependency>
+                <groupId>org.tinylog</groupId>
+                <artifactId>tinylog-impl</artifactId>
+                <version>${tinylog.version}</version>
+            </dependency>
+
+            <dependency>
+                <groupId>org.tinylog</groupId>
+                <artifactId>slf4j-tinylog</artifactId>
+                <version>${tinylog.version}</version>
+            </dependency>
+
             <dependency>
                 <groupId>org.testcontainers</groupId>
                 <artifactId>testcontainers-bom</artifactId>
-                <version>1.19.8</version>
+                <version>${testcontainers.version}</version>
                 <scope>import</scope>
                 <type>pom</type>
             </dependency>