Elasticsearch - Java API 操作 ES7.16.0+、ES8.x 索引，文档；高级搜索（八）

谁践踏了优雅 2023-09-27 09:47 114阅读 0赞

#### 阅读本文前可先参考 ####

[Elasticsearch - Java API 操作 ES7.15.0、ES7.x 索引，文档；高级搜索（六）\_MinggeQingchun的博客-CSDN博客][Elasticsearch - Java API _ ES7.15.0_ES7.x _MinggeQingchun_-CSDN]

[Elasticsearch - Java API（Lambda 表达式） 操作 ES7.16.0+、ES8.x 索引，文档；高级搜索（七）\_MinggeQingchun的博客-CSDN博客][Elasticsearch - Java API_Lambda _ _ ES7.16.0_ES8.x _MinggeQingchun_-CSDN]

[Elasticsearch][] 软件是由 Java 语言开发的，所以也可以通过 Java API 的方式对 Elasticsearch服务进行访问

> **以 Elasticsearch****7.16.0版本为例**

1、创建空工程elasticsearch-demo，创建普通Java的maven模块elasticsearch-test

2、添加依赖

查看Elasticsearch官网文档

[Installation | Elasticsearch Java API Client \[7.16\] | Elastic][Installation _ Elasticsearch Java API Client _7.16_ _ Elastic]

<dependencies>
     
        
    
    
    
    
    
     
        
        <dependency>
          <groupId>co.elastic.clients</groupId>
          <artifactId>elasticsearch-java</artifactId>
          <version>7.16.0</version>
        </dependency>
     
        
        <dependency>
          <groupId>org.apache.logging.log4j</groupId>
          <artifactId>log4j-api</artifactId>
          <version>2.17.0</version>
        </dependency>
        <dependency>
          <groupId>org.apache.logging.log4j</groupId>
          <artifactId>log4j-core</artifactId>
          <version>2.17.0</version>
        </dependency>
     
        <dependency>
          <groupId>com.fasterxml.jackson.core</groupId>
          <artifactId>jackson-databind</artifactId>
          <version>2.12.3</version>
        </dependency>
     
        
        <dependency>
          <groupId>junit</groupId>
          <artifactId>junit</artifactId>
          <version>4.12</version>
        </dependency>
      </dependencies>

## 一、Elasticsearch 客户端对象 ##

> 在**Elasticsearch7.15**版本之后，Elasticsearch官方将它的高级客户端 **RestHighLevelClient** 标记为弃用状态
> 
> 同时推出了全新的Java API客户端Elasticsearch Java API Client，该客户端也将在Elasticsearch8.0及以后版本中成为官方推荐使用的客户端

就像连接 MySQL 数据库一样，Java 通过客户端操作 Elasticsearch 也要获取到连接后才可以使用

可参考

[https://blog.csdn.net/MinggeQingchun/article/details/126830831][https_blog.csdn.net_MinggeQingchun_article_details_126830831]

在第一台服务器节点 es-node-1 设置集群多节点 HTTP 证书

基于https 安全的 Elasticsearch 服务，所以首先我们需要将之前的证书进行一个转换

cd /opt/software/elasticsearch-7.16.0/config/certs/
    openssl pkcs12 -in elastic-stack-ca.p12 -clcerts -nokeys -out java-ca.crt

![540e66afc5994e2eae16be5ad385cb49.png][]

将其下载下来并导入到Java项目中

![47b2c514b7a740848ec273fad40b1d58.png][]

#### 创建客户端 ####

import co.elastic.clients.elasticsearch.*;
    import co.elastic.clients.json.jackson.JacksonJsonpMapper;
    import co.elastic.clients.transport.ElasticsearchTransport;
    import co.elastic.clients.transport.rest_client.RestClientTransport;
    import org.apache.http.HttpHost;
    import org.apache.http.auth.*;
    import org.apache.http.client.*;
    import org.apache.http.conn.ssl.NoopHostnameVerifier;
    import org.apache.http.impl.client.*;
    import org.apache.http.impl.nio.client.HttpAsyncClientBuilder;
    import org.apache.http.ssl.*;
    import org.elasticsearch.client.*;
    import javax.net.ssl.SSLContext;
    import java.io.IOException;
    import java.io.InputStream;
    import java.nio.file.*;
    import java.security.KeyManagementException;
    import java.security.KeyStore;
    import java.security.KeyStoreException;
    import java.security.NoSuchAlgorithmException;
    import java.security.cert.*;
    
    /**
     * 在Elasticsearch7.15版本之后，Elasticsearch官方将它的高级客户端 RestHighLevelClient 标记为弃用状态
     *   同时推出了全新的Java API客户端Elasticsearch Java API Client，该客户端也将在Elasticsearch8.0及以后版本中成为官方推荐使用的客户端
     * Elasticsearch Java API Client 支持除 Vector tile search API 和 Find structure API 之外的所有 Elasticsearch API。
     *   且支持所有API数据类型，并且不再有原始JsonValue属性。它是针对Elasticsearch8.0及之后版本的客户端
     */
    public class ESClient {
        public static void main(String[] args) throws CertificateException, IOException, KeyStoreException, NoSuchAlgorithmException, KeyManagementException {
    
            final CredentialsProvider credentialsProvider = new BasicCredentialsProvider();
            credentialsProvider.setCredentials(AuthScope.ANY,
                    new UsernamePasswordCredentials("elastic", "O3x0hfu7i=ZbQvlktCnd"));
            Path caCertificatePath = Paths.get("ca.crt");
            CertificateFactory factory =
                    CertificateFactory.getInstance("X.509");
            Certificate trustedCa;
    
            try (InputStream is = Files.newInputStream(caCertificatePath)) {
                trustedCa = factory.generateCertificate(is);
            }
    
            KeyStore trustStore = KeyStore.getInstance("pkcs12");
            trustStore.load(null, null);
            trustStore.setCertificateEntry("ca", trustedCa);
            SSLContextBuilder sslContextBuilder = SSLContexts.custom()
                    .loadTrustMaterial(trustStore, null);
    
            final SSLContext sslContext = sslContextBuilder.build();
            RestClientBuilder builder = RestClient.builder(
                    new HttpHost("linux1", 9200, "https"))
                    .setHttpClientConfigCallback(new RestClientBuilder.HttpClientConfigCallback() {
                        @Override
                        public HttpAsyncClientBuilder customizeHttpClient(
                                HttpAsyncClientBuilder httpClientBuilder) {
                            return httpClientBuilder.setSSLContext(sslContext)
                                    .setSSLHostnameVerifier(NoopHostnameVerifier.INSTANCE)
                                    .setDefaultCredentialsProvider(credentialsProvider);
                        }
                    });
    
            // 创建低级客户端
            RestClient restClient = RestClient.builder(new HttpHost("localhost",9200)).build();
    
            // 使用Jackson映射器创建传输层
            ElasticsearchTransport transport = new RestClientTransport(restClient,new JacksonJsonpMapper());
    
            // 创建API 同步客户端
            ElasticsearchClient esClient = new ElasticsearchClient(transport);
            // 创建API 异步客户端
            ElasticsearchAsyncClient asyncClient = new ElasticsearchAsyncClient(transport);
    
            // 关闭ES客户端
            try {
                transport.close();
                restClient.close();
            } catch (IOException e) {
                e.printStackTrace();
            }
        }
    }

##  ##

## 二、索引操作 ##

// 创建索引
    CreateIndexRequest request = new 
    CreateIndexRequest.Builder().index("myindex").build();
    final CreateIndexResponse createIndexResponse = 
    client.indices().create(request);
    System.out.println("创建索引成功：" + createIndexResponse.acknowledged());
    
    
    // 查询索引
    GetIndexRequest getIndexRequest = new 
    GetIndexRequest.Builder().index("myindex").build();
    final GetIndexResponse getIndexResponse = 
    client.indices().get(getIndexRequest);
    System.out.println("索引查询成功：" + getIndexResponse.result());
    
    
    // 删除索引
    DeleteIndexRequest deleteIndexRequest = new 
    DeleteIndexRequest.Builder().index("myindex").build();
    final DeleteIndexResponse delete = client.indices().delete(deleteIndexRequest);
    final boolean acknowledged = delete.acknowledged();
    System.out.println("删除索引成功：" + acknowledged);

## 三、文档操作 ##

// 创建文档
    IndexRequest indexRequest = new IndexRequest.Builder()
     .index("myindex")
     .id(user.getId().toString())
     .document(user)
     .build();
    final IndexResponse index = client.index(indexRequest);
    System.out.println("文档操作结果:" + index.result());
    
    
    // 批量创建文档
    final List<BulkOperation> operations = new ArrayList<BulkOperation>();
    for ( int i= 1;i <= 5; i++ ) {
     final CreateOperation.Builder builder = new CreateOperation.Builder();
     builder.index("myindex");
     builder.id("200" + i);
     builder.document(new User(2000 + i, 30 + i * 10, "zhangsan" + i, "beijing", 
    1000 + i*1000));
     final CreateOperation<Object> objectCreateOperation = builder.build();
     final BulkOperation bulk = new 
    BulkOperation.Builder().create(objectCreateOperation).build();
     operations.add(bulk);
    }
    BulkRequest bulkRequest = new 
    BulkRequest.Builder().operations(operations).build();
    final BulkResponse bulkResponse = client.bulk(bulkRequest);
    System.out.println("数据操作成功：" + bulkResponse);
    
    
    // 删除文档
    DeleteRequest deleteRequest = new 
    DeleteRequest.Builder().index("myindex").id("1001").build();
    client.delete(deleteRequest);

## 四、文档高级查询 ##

final SearchRequest.Builder searchRequestBuilder = new SearchRequest.Builder().index("myindex1");
            MatchQuery matchQuery = new
                    MatchQuery.Builder().field("city").query(FieldValue.of("beijing")).build();
            Query query = new Query.Builder().match(matchQuery).build();
            searchRequestBuilder.query(query);
            SearchRequest searchRequest = searchRequestBuilder.build();
            final SearchResponse<Object> search = esClient.search(searchRequest,
                    Object.class);
            System.out.println(search);

## 五、**客户端异步操作**  ##

// 创建索引
            asyncClient.indices().create(
                    req -> {
                        req.index("newindex");
                        return req;
                    }
            ).whenComplete(
                    (resp, error) -> {
                        System.out.println("回调函数");
                        if ( resp != null ) {
                            System.out.println(resp.acknowledged());
                        } else {
                            error.printStackTrace();
                        }
                    }
            );
            
            System.out.println("主线程操作...");
            
            asyncClient.indices().create(
                    req -> {
                        req.index("newindex");
                        return req;
                    } )
                    .thenApply(
                            resp -> {
                                return resp.acknowledged();
                            } )
                    .whenComplete(
                            (resp, error) -> {
                                System.out.println("回调函数");
                                if ( !resp ) {
                                    System.out.println();
                                } else {
                                    error.printStackTrace();
                                }
                            }
                    );

[Elasticsearch - Java API _ ES7.15.0_ES7.x _MinggeQingchun_-CSDN]: https://blog.csdn.net/MinggeQingchun/article/details/126762570
[Elasticsearch - Java API_Lambda _ _ ES7.16.0_ES8.x _MinggeQingchun_-CSDN]: https://blog.csdn.net/MinggeQingchun/article/details/126717979?csdn_share_tail=%7B%22type%22%3A%22blog%22%2C%22rType%22%3A%22article%22%2C%22rId%22%3A%22126717979%22%2C%22source%22%3A%22MinggeQingchun%22%7D
[Elasticsearch]: https://so.csdn.net/so/search?q=Elasticsearch&spm=1001.2101.3001.7020
[Installation _ Elasticsearch Java API Client _7.16_ _ Elastic]: https://www.elastic.co/guide/en/elasticsearch/client/java-api-client/7.16/installation.html
[https_blog.csdn.net_MinggeQingchun_article_details_126830831]: https://blog.csdn.net/MinggeQingchun/article/details/126830831
[540e66afc5994e2eae16be5ad385cb49.png]: https://img-blog.csdnimg.cn/540e66afc5994e2eae16be5ad385cb49.png
[47b2c514b7a740848ec273fad40b1d58.png]: https://img-blog.csdnimg.cn/47b2c514b7a740848ec273fad40b1d58.png