Elasticsearch Integration with Spring Boot: Dependency Setup, High‑Level Client, CRUD Operations, Bulk Processing and Search

1. Import Elasticsearch Dependency

Add the Spring Boot Elasticsearch starter to

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

in your pom.xml. Ensure the version matches your Spring Boot version.

2. Create a High‑Level Client

Define a configuration class to expose a RestHighLevelClient bean:

@Configuration
public class ElasticSearchClientConfig {
    @Bean
    public RestHighLevelClient restHighLevelClient() {
        return new RestHighLevelClient(
            RestClient.builder(new HttpHost("SERVER_IP", 9200, "http")));
    }
}

3. Basic Usage

All CRUD operations are demonstrated with JUnit tests.

a) Index Management (Create, Exist, Delete)

@Test
void testCreateIndex() throws IOException {
    CreateIndexRequest request = new CreateIndexRequest("ljx666");
    CreateIndexResponse response = restHighLevelClient.indices().create(request, RequestOptions.DEFAULT);
    System.out.println(response);
}

@Test
void testExistIndex() throws IOException {
    GetIndexRequest request = new GetIndexRequest("ljx666");
    boolean exists = restHighLevelClient.indices().exists(request, RequestOptions.DEFAULT);
    System.out.println(exists);
}

@Test
void testDeleteIndex() throws IOException {
    DeleteIndexRequest request = new DeleteIndexRequest("ljx666");
    AcknowledgedResponse delete = restHighLevelClient.indices().delete(request, RequestOptions.DEFAULT);
    System.out.println(delete.isAcknowledged());
}

b) Document CRUD

@Test
void testAddUser() throws IOException {
    User user = new User("Go", 21, new String[]{"内卷", "吃饭"});
    IndexRequest request = new IndexRequest("ljx666");
    request.id("6").timeout("1s");
    request.source(JSONValue.toJSONString(user), XContentType.JSON);
    IndexResponse indexResponse = restHighLevelClient.index(request, RequestOptions.DEFAULT);
    System.out.println(indexResponse);
}

@Test
void testGetUser() throws IOException {
    GetRequest request = new GetRequest("ljx666", "1");
    GetResponse getResponse = restHighLevelClient.get(request, RequestOptions.DEFAULT);
    System.out.println(getResponse.getSourceAsString());
}

@Test
void testUpdateUser() throws IOException {
    UpdateRequest request = new UpdateRequest("ljx666", "6");
    User user = new User("GoGo", 21, new String[]{"内卷", "吃饭"});
    request.doc(JSONValue.toJSONString(user), XContentType.JSON);
    UpdateResponse updateResponse = restHighLevelClient.update(request, RequestOptions.DEFAULT);
    System.out.println(updateResponse.status());
}

@Test
void testDeleteUser() throws IOException {
    DeleteRequest request = new DeleteRequest("ljx666", "6");
    DeleteResponse deleteResponse = restHighLevelClient.delete(request, RequestOptions.DEFAULT);
    System.out.println(deleteResponse.status());
}

c) Bulk CRUD

@Test
void testBulkAddUser() throws IOException {
    BulkRequest bulkRequest = new BulkRequest();
    bulkRequest.timeout("10s");
    List<User> list = new ArrayList<>();
    list.add(new User("Java", 25, new String[]{"内卷"}));
    // ... add more users ...
    int id = 1;
    for (User u : list) {
        bulkRequest.add(new IndexRequest("ljx666")
            .id(String.valueOf(id++))
            .source(JSONValue.toJSONString(u), XContentType.JSON));
    }
    BulkResponse bulkResponse = restHighLevelClient.bulk(bulkRequest, RequestOptions.DEFAULT);
    System.out.println(bulkResponse.hasFailures());
}

d) Search Queries (Match All, Multi‑Match, Pagination, Highlight)

@Test
void testSearch() throws IOException {
    SearchRequest searchRequest = new SearchRequest("ljx666");
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.matchAllQuery()); // or multiMatchQuery("java", "name")
    sourceBuilder.from(0).size(5);
    HighlightBuilder highlightBuilder = new HighlightBuilder();
    highlightBuilder.field("name").preTags("<span style='color:red;'>").postTags("</span>");
    sourceBuilder.highlighter(highlightBuilder);
    searchRequest.source(sourceBuilder);
    SearchResponse searchResponse = restHighLevelClient.search(searchRequest, RequestOptions.DEFAULT);
    System.out.println(searchResponse.getHits().getTotalHits().value);
    for (SearchHit hit : searchResponse.getHits().getHits()) {
        System.out.println("Score:" + hit.getScore());
        System.out.println("Index:" + hit.getIndex() + " ID:" + hit.getId());
        System.out.println(hit.getSourceAsMap());
    }
}

4. Summary

The typical workflow is: create a request → set request parameters (index, id, data, timeout, etc.) → invoke the corresponding client method → receive a response object → extract needed information such as source, status, or hit details.

5. Important Notes

If you do not specify an ID, Elasticsearch generates a random one.

Avoid hard‑coding index names; use constants or enums to simplify future changes.

All Elasticsearch libraries must be version‑compatible; mismatched versions cause connection failures.

Elasticsearch is memory‑intensive; run it on a server with sufficient RAM to prevent OOM kills.