Elasticsearch

Spring boot에서 Elasticsearch를 사용하는 데는 

주로 spring-Data-Elastic과 spring-boot-starter-data-elastic이 주로 쓰인다

이중에서 spring-boot-starter-data-elastic는 rest-high-level-client라는 걸 이용했었는데
Elasticsearch 7.15.0에서 depreated되었다

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high.html

Java High Level REST Client | Java REST Client [7.17] | Elastic

 

그래서 최신 버전은 이제 ElasticsearchClient를 사용해야 한다.

 

 

 

이번 예제는 최신 버전을 사용할 것이기 때문에 ElasticsearchClient를 사용하겠다

 

 

 

import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.ComponentScan;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.config.ElasticsearchConfigurationSupport;
import org.springframework.data.elasticsearch.repository.config.EnableElasticsearchRepositories;

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.json.jackson.JacksonJsonpMapper;
import co.elastic.clients.transport.ElasticsearchTransport;
import co.elastic.clients.transport.rest_client.RestClientTransport;

@Configuration
@EnableElasticsearchRepositories(basePackages = "com.example.demo.elasticSearch")
@ComponentScan(basePackages = { "com.example.demo.elasticSearch" })
public class elasticConfig extends ElasticsearchConfigurationSupport{
    
    @Bean
    public ElasticsearchClient esClient() {
        RestClient client = RestClient
        .builder(new HttpHost("localhost", 9200, "http"))
        .build();
        ElasticsearchTransport transport = new RestClientTransport(client, new JacksonJsonpMapper());
        return new ElasticsearchClient(transport);
    }

}

 

 

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

interface elasticRepository extends ElasticsearchRepository<my_entity, String> {
    
}

 

 

import java.util.Optional;

import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Service;

import co.elastic.clients.elasticsearch.ElasticsearchClient;
import co.elastic.clients.elasticsearch.core.GetResponse;

@Service
public class elasticService {
    
    @Autowired
    elasticRepository repo;

    @Autowired
    ElasticsearchClient client;

    public void save_data(my_entity entity) {
        repo.save(entity);
        
    }

    public void save_data2(my_entity entity) {
        try {
        client.index(i -> i
        .index("my_index")
        .id(entity.getId())
        .document(entity));
        } catch(Exception e) {
            
        }
    }
    public my_entity get_data(String id) {
        Optional<my_entity> entity = repo.findById(id);
        return entity.get();
    }

    public my_entity get_data2(String id) { 
        my_entity entity = null;  
        try {
            GetResponse<my_entity> res = client.get(g-> g
            .index("my_index")
            .id(id),
            my_entity.class);
            entity = res.source();
        } catch(Exception e) {
                
        }
        return entity;    
    }

    public void update_data(String id, String name) {
        if(get_data(id) != null) {
            repo.save(new my_entity(id, name));
        }
    }

    public void update_data2(String id, String name) {
        try {
            client.update(u -> u
                .index("my_index")
                .id(id)
                .doc(new my_entity(id, name)),
                my_entity.class
            );
        } catch(Exception e) {

        }
    }

    public void delete_data(String id) {
        repo.deleteById(id);
    }

    public void delete_data2(String id) {
        try {
        client.delete(d -> d
            .index("my_index")
            .id(id));
        } catch(Exception e) {
            
        }
    }
}

 

 

repository를 이용한 것과 바로 esclient를 이용한 것에 작은 차이가 있다

 

 

repository를 이용해 저장한 데이터는 _class field에 자신의 class를 기록해 두는데 이게 있을 경우 

esclient로 바로 읽을 경우 오류가 생긴다

 

반대로 esClient로 저장한 데이터는 _class가 없는데 이 데이터를 repository로 읽어 들이는 데에는 아무런 지장이 없었다