Integrating Elasticsearch with Spring Boot for Full-Text Search

In modern applications, efficient management and fast retrieval of large amounts of data are crucial; Elasticsearch provides a powerful open‑source full‑text search engine.

This article demonstrates how to integrate Elasticsearch with a Spring Boot project to achieve full‑text search capabilities.

Creating a Spring Boot Project

Start a new Spring Boot project using Spring Initializr, selecting the required dependencies.

Adding Elasticsearch Dependency

Include the Spring Data Elasticsearch starter in pom.xml:

<dependency>
    <groupId>org.springframework.boot</groupId>
    <artifactId>spring-boot-starter-data-elasticsearch</artifactId>
</dependency>

This brings in Spring Data Elasticsearch for easier usage.

Configuring Elasticsearch Connection

Add connection settings to application.properties:

spring:
  data:
    elasticsearch:
      cluster-nodes: localhost:9200

Ensure an Elasticsearch instance is running locally on port 9200.

Creating the Entity Class

Define a simple entity mapped to an Elasticsearch index:

import org.springframework.data.annotation.Id;
import org.springframework.data.elasticsearch.annotations.Document;

@Document(indexName = "documents", type = "document")
public class DocumentEntity {
    @Id
    private String id;
    private String title;
    private String content;
    // constructors, getters, setters omitted
}

Creating the Elasticsearch Repository

Extend ElasticsearchRepository to interact with the index:

import org.springframework.data.elasticsearch.repository.ElasticsearchRepository;

public interface DocumentRepository extends ElasticsearchRepository<DocumentEntity, String> {
    // custom query methods can be added here
}

Implementing the Service Layer

Write a service that uses the repository for search and save operations:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;
import java.util.List;

@Service
public class DocumentService {
    @Autowired
    private DocumentRepository documentRepository;

    public List<DocumentEntity> searchDocuments(String keyword) {
        // example custom method; adjust as needed
        return documentRepository.findByTitleOrContent(keyword, keyword);
    }

    public void saveDocument(DocumentEntity document) {
        documentRepository.save(document);
    }
}

Creating the Controller Layer

Expose HTTP endpoints for searching and adding documents:

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.web.bind.annotation.*;

import java.util.List;

@RestController
@RequestMapping("/documents")
public class DocumentController {
    @Autowired
    private DocumentService documentService;

    @GetMapping("/search")
    public List<DocumentEntity> searchDocuments(@RequestParam String keyword) {
        return documentService.searchDocuments(keyword);
    }

    @PostMapping("/add")
    public void addDocument(@RequestBody DocumentEntity document) {
        documentService.saveDocument(document);
    }
}

Testing

Run the Spring Boot application and use tools such as Postman to test the search and add‑document endpoints.

Conclusion

The example shows how to integrate Elasticsearch into a Spring Boot application, enabling efficient full‑text search and improving data management for large datasets. Further enhancements can leverage advanced Elasticsearch features according to specific business needs.