SpringBoot集成ElasticSearch8.10.4版本

由于Elasticsearch7.x版本和8.x版本差距较大，并且在8.x版本中放弃了对旧版本中的Java REST Client（High Level Rest Client (HLRC)）的支持，从而替换为推荐使用的Java API Client 8.x。

注意：springboot版本尽量不要低于2.6.4，因为jackson与springboot也需要兼容。

这里学习和记录8.10.4版本的集成和使用。

1、找到原生的依赖

<dependency>
    <groupId>co.elastic.clientsgroupId>
    <artifactId>elasticsearch-javaartifactId>
    <version>8.10.4version>
    <exclusions>
        <exclusion>
            <groupId>org.elasticsearch.clientgroupId>
            <artifactId>elasticsearch-rest-clientartifactId>
        exclusion>
    exclusions>
dependency>


<dependency>
    <groupId>org.elasticsearch.clientgroupId>
    <artifactId>elasticsearch-rest-clientartifactId>
    <version>8.10.4version>
dependency>

<dependency>
    <groupId>com.fasterxml.jackson.coregroupId>
    <artifactId>jackson-databindartifactId>
    <version>2.13.2version>
dependency>


<dependency>
    <groupId>org.glassfishgroupId>
    <artifactId>jakarta.jsonartifactId>
    <version>2.0.1version>
dependency>

2、核心配置类

@Configuration
public class ElasticConfig {

    //创造连接，并返回json格式数据
    @Bean
    public ElasticsearchClient elasticsearchClient(){
        RestClient client = RestClient.builder(new HttpHost("localhost",9200,"http")).build();
        ElasticsearchTransport transport = new RestClientTransport(client, new JacksonJsonpMapper());
        return new ElasticsearchClient(transport);
    }

}

3、在Test类中对索引进行增删改查测试

@Test
void testCreateIndex() throws IOException {

    //创建索引
    CreateIndexResponse response = client.indices().create(c -> c.index("user"));

    //查询索引
    GetIndexResponse getIndexResponse = client.indices().get(i -> i.index("user"));

    //判断索引是否存在
    BooleanResponse booleanResponse = client.indices().exists(e -> e.index("user"));

    //删除索引
    DeleteIndexResponse deleteIndexResponse = client.indices().delete(d -> d.index("user"));

}

4、在Test类中对document进行增删改查测试

创建实体类：

@Data
@AllArgsConstructor
@NoArgsConstructor
public class Product {

    private String id;

    private String SKu;

    private double price;
}

document测试：

//document CRUD
@Test
void testDocumentCRUD() throws IOException {
    Product product = new Product("bk-1", "City bike", 123.0);
    Product product2 = new Product("bk-2", "Countryside bike", 150.0);

    //插入document
    IndexResponse indexResponse = client.index(i -> i.index("product").id(product.getSKu()).document(product));
    System.out.println(indexResponse);

    //更新document
    UpdateResponse<Product> updateResponse = client.update(u -> u.index("product").id(product.getSKu()).doc(product2),Product.class);
    System.out.println(updateResponse);

    //判断document是否存在，返回boolean类型
    BooleanResponse booleanResponse = client.exists(e -> e.index("product").id(product.getSKu()));
    System.out.println(booleanResponse.value());

    //查询document,返回对象
    GetResponse<Product> getResponse = client.get(g -> g.index("product").id(product.getSKu()),Product.class);
    System.out.println(getResponse.source());

    //删除document
    DeleteResponse deleteResponse = client.delete(d -> d.index("product").id(product.getSKu()));
}

5、批量插入document

//批量插入document
@Test
void batchCreate() throws IOException {
    List<Product> productList = new ArrayList<>();
    for (int i = 0; i < 5; i++) {
        productList.add(new Product("bk-"+i, "city bike"+i, 100+i));
    }

    List<BulkOperation> bulkOperations = new ArrayList<>();

    for(Product product : productList){
        bulkOperations.add(BulkOperation.of(o -> o.index(i -> i.id(product.getSKu()).document(product))));
    }

    BulkResponse response = client.bulk(b -> b.index("product").operations(bulkOperations));

}

6、复杂条件查询

// 复杂条件查询
@Test
void searchTest() throws IOException {
    SearchResponse<Product> searchResponse = client.search(s -> s.index("product")
                             //精确查询id字段中包含bk的
                             .query(q -> q.term(t -> t.field("id").value(v -> v.stringValue("bk"))))
                             //高亮查询
                             .highlight(q -> q.fields("id",o -> o.matchedFields("")).preTags("
").postTags("
"))
                             //分页
                             .from(0)
                             .size(4)
                             //排序
                             .sort(f -> f.field(o -> o.field("price").order(SortOrder.Desc))),Product.class);

    for(Hit<Product> hit : searchResponse.hits().hits()){
        System.out.println(hit);
    }

}

返回查询结果：

Hit: {"_index":"product","_id":"city bike4","_score":null,"highlight":{"id":["
bk
-4"]},"_source":"Product(id=bk-4, SKu=city bike4, price=104.0)","sort":[104.0]}
Hit: {"_index":"product","_id":"city bike3","_score":null,"highlight":{"id":["
bk
-3"]},"_source":"Product(id=bk-3, SKu=city bike3, price=103.0)","sort":[103.0]}
Hit: {"_index":"product","_id":"city bike2","_score":null,"highlight":{"id":["
bk
-2"]},"_source":"Product(id=bk-2, SKu=city bike2, price=102.0)","sort":[102.0]}
Hit: {"_index":"product","_id":"city bike1","_score":null,"highlight":{"id":["
bk
-1"]},"_source":"Product(id=bk-1, SKu=city bike1, price=101.0)","sort":[101.0]}