Elasticsearch8.x版本中RestHighLevelClient被弃用，新版本中全新的Java客 ...

Es的java API客户端

在Es7.15版本之后，es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 title search API和Find structure API之外的所有Elasticsearch API。且支持所有API数据类型，而且不再有原始JSON Value属性。它是针对Elasticsearch8.0及之后版本的客户端。
感爱好的小同伴可以去官方文档看看：Elasticsearch官网8.x版本下Java客户端文档—Elasticsearch Java API Client使用
新建maven项目

maven中引入依赖坐标

1.         <dependency>
2.             <groupId>co.elastic.clients</groupId>
3.             <artifactId>elasticsearch-java</artifactId>
4.             <version>8.1.0</version>
5.         </dependency>
6.          <dependency>
7.             <groupId>com.fasterxml.jackson.core</groupId>
8.             <artifactId>jackson-databind</artifactId>
9.             <version>2.13.1</version>
10.         </dependency>
11.         <dependency>
12.             <groupId>junit</groupId>
13.             <artifactId>junit</artifactId>
14.             <version>4.12</version>
15.         </dependency>
16.         <dependency>
17.             <groupId>org.projectlombok</groupId>
18.             <artifactId>lombok</artifactId>
19.             <version>1.18.22</version>
20.             <scope>provided</scope>
21.         </dependency>

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创建毗连

1.     @Test
2.     public void create() throws IOException {
3.         // 创建低级客户端
4.         RestClient restClient = RestClient.builder(
5.                 new HttpHost("localhost", 9200)
6.         ).build();
7.         // 使用Jackson映射器创建传输层
8.         ElasticsearchTransport transport = new RestClientTransport(
9.                 restClient, new JacksonJsonpMapper()
10.         );
11.         // 创建API客户端
12.         ElasticsearchClient client = new ElasticsearchClient(transport);
14.         // 关闭ES客户端
15.         transport.close();
16.         restClient.close();
17.     }

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索引index的基本语法

创建索引

1.     @Test
2.     public void create() throws IOException {
3.         // 创建低级客户端
4.         RestClient restClient = RestClient.builder(
5.                 new HttpHost("localhost", 9200)
6.         ).build();
7.         // 使用Jackson映射器创建传输层
8.         ElasticsearchTransport transport = new RestClientTransport(
9.                 restClient, new JacksonJsonpMapper()
10.         );
11.         // 创建API客户端
12.         ElasticsearchClient client = new ElasticsearchClient(transport);
13.         // 创建索引
14.         CreateIndexResponse createIndexResponse = client.indices().create(c -> c.index("user_test"));
15.         // 响应状态
16.         Boolean acknowledged = createIndexResponse.acknowledged();
17.         System.out.println("索引操作 = " + acknowledged);
19.         // 关闭ES客户端
20.         transport.close();
21.         restClient.close();
22.     }

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查询索引

1.     @Test
2.     public void query() throws IOException {
3.         RestClient restClient = RestClient.builder(
4.                 new HttpHost("localhost",9200)
5.         ).build();
6.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
7.         ElasticsearchClient client = new ElasticsearchClient(transport);
9.         // 查询索引
10.         GetIndexResponse getIndexResponse = client.indices().get(e -> e.index("user_test"));
11.         System.out.println("getIndexResponse.result() = " + getIndexResponse.result());
12.         System.out.println("getIndexResponse.result().keySet() = " + getIndexResponse.result().keySet());
14.         transport.close();
15.         restClient.close();
16.     }

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删除索引

1.     @Test
2.     public void delete() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 删除索引
8.         DeleteIndexResponse deleteIndexResponse = client.indices().delete(e -> e.index("user_test"));
9.         System.out.println("删除操作 = " + deleteIndexResponse.acknowledged());
11.         transport.close();
12.         restClient.close();
13.     }

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文档document的操作

创建User对象

1. @Data
2. @AllArgsConstructor
3. @NoArgsConstructor
4. public class User {
5.     private String name;
6.     private String sex;
7.     private Integer age;
8. }

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添加document

1.     @Test
2.     public void addDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 向user对象中添加数据
8.         User user = new User("java客户端", "男", 18);
9.         // 向索引中添加数据
10.         CreateResponse createResponse = client.create(e -> e.index("user_test").id("1001").document(user));
11.         System.out.println("createResponse.result() = " + createResponse.result());
13.         transport.close();
14.         restClient.close();
15.     }

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1. $\color{red}{注：index中参数为文档所属的索引名，id中参数为当文档的id，document为文档数据，新版本支持直接传入java对象.} $  

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查询document

1.     @Test
2.     public void queryDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 构建请求
8.         GetResponse<User> getResponse = client.get(e -> e.index("user_test").id("1001"), User.class);
9.         System.out.println("getResponse.source().toString() = " + getResponse.source().toString());
11.         transport.close();
12.         restClient.close();
13.     }

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修改document

1.     @Test
2.     public void modifyDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 使用map集合封装需要修改的内容
8.         Map<String, Object> map = new HashMap<>();
9.         map.put("name", "java客户端aaa");
10.         // 构建请求
11.         UpdateResponse<User> updateResponse = client.update(e -> e.index("user_test").id("1001").doc(map), User.class);
12.         System.out.println("updateResponse.result() = " + updateResponse.result());
14.         transport.close();
15.         restClient.close();
16.     }

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删除document

1.     @Test
2.     public void removeDocument() throws  IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 构建请求
8.         DeleteResponse deleteResponse = client.delete(e -> e.index("user_test").id("1001"));
9.         System.out.println("deleteResponse.result() = " + deleteResponse.result());
11.         transport.close();
12.         restClient.close();
13.     }

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批量添加document

1.     @Test
2.     public void batchAddDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 构建一个批量数据集合
8.         List<BulkOperation> list = new ArrayList<>();
9.         list.add(new BulkOperation.Builder().create(
10.                 d -> d.document(new User("test2", "男", 19)).id("1002").index("user_test")).build());
11.         list.add(new BulkOperation.Builder().create(
12.                 d -> d.document(new User("test3", "男", 20)).id("1003").index("user_test")).build());
13.         list.add(new BulkOperation.Builder().create(
14.                 d -> d.document(new User("test4", "女", 21)).id("1004").index("user_test")).build());
15.         // 调用bulk方法执行批量插入操作
16.         BulkResponse bulkResponse = client.bulk(e -> e.index("user_test").operations(list));
17.         System.out.println("bulkResponse.items() = " + bulkResponse.items());
19.         transport.close();
20.         restClient.close();
21.     }

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批量删除

1.     @Test
2.     public void batchDeleteDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 构建一个批量数据集合
8.         List<BulkOperation> list = new ArrayList<>();
9.         list.add(new BulkOperation.Builder().delete(
10.                 d -> d.id("1002").index("user_test")).build());
11.         list.add(new BulkOperation.Builder().delete(
12.                 d -> d.id("1003").index("user_test")).build());
13.         // 调用bulk方法执行批量插入操作
14.         BulkResponse bulkResponse = client.bulk(e -> e.index("user_test").operations(list));
15.         System.out.println("bulkResponse.items() = " + bulkResponse.items());
17.         transport.close();
18.         restClient.close();
19.     }

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全量查询

1.     @Test
2.     public void queryAllDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 全量查询
8.         SearchResponse<User> searchResponse = client.search(e -> e.index("user_test").query(q -> q.matchAll(m -> m)), User.class);
9.         HitsMetadata<User> hits = searchResponse.hits();
10.         for (Hit<User> hit : hits.hits()) {
11.             System.out.println("user = " + hit.source().toString());
12.         }
13.         System.out.println("searchResponse.hits().total().value() = " + searchResponse.hits().total().value());
15.         transport.close();
16.         restClient.close();
17.     }

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分页查询

1.     @Test
2.     public void pagingQueryDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 分页查询
8.         SearchResponse<User> searchResponse = client.search(
9.                 s -> s.index("user_test")
10.                         .query(q -> q.matchAll(m -> m))
11.                         .from(2)
12.                         .size(2)
13.                 , User.class);
14.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
16.         transport.close();
17.         restClient.close();
18.     }

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排序查询

1.     @Test
2.     public void sortQueryDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 排序查询
8.         SearchResponse<User> searchResponse = client.search(
9.                 s -> s.index("user_test")
10.                         .query(q -> q.matchAll(m -> m))
11.                         .sort(o -> o.field(f -> f.field("age").order(SortOrder.Asc)))
12.                 , User.class);
13.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
15.         transport.close();
16.         restClient.close();
17.     }

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条件查询

1.     @Test
2.     public void conditionQueryDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 条件查询
8.         SearchResponse<User> searchResponse = client.search(
9.                 s -> s.index("user_test").query(q -> q.matchAll(m -> m))
10.                         .sort(o -> o.field(f -> f.field("age").order(SortOrder.Asc)))
11.                         .source(r -> r.filter(f -> f.includes("name", "age").excludes("")))
12.                 , User.class);
13.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
15.         transport.close();
16.         restClient.close();
17.     }

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组合查询

1.     @Test
2.     public void combinationQueryDocument() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 组合查询
8.         SearchResponse<User> searchResponse = client.search(
9.                 s -> s.index("user_test").query(q -> q.bool(b -> b
10.                         .must(m -> m.match(u -> u.field("age").query(21)))
11.                         .must(m -> m.match(u -> u.field("sex").query("男")))
12.                         .mustNot(m -> m.match(u -> u.field("sex").query("女")))
13.                 ))
14.                 , User.class);
15.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
17.         transport.close();
18.         restClient.close();
19.     }

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1.     @Test
2.     public void combinationQueryDocument2() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 组合查询
8.         SearchResponse<User> searchResponse = client.search(
9.                 s -> s.index("user_test").query(q -> q.bool(b -> b
10.                         .should(h -> h.match(u -> u.field("age").query(19)))
11.                         .should(h -> h.match(u -> u.field("sex").query("男")))
12.                 ))
13.                 , User.class);
14.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
16.         transport.close();
17.         restClient.close();
18.     }

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must是必须满足所有条件，should只要满足一个就行
范围查询

1.     @Test
2.     public void scopeQueryDocument2() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 范围查询，gte()表示取大于等于，gt()表示大于，lte()表示小于等于
8.         SearchResponse<User> searchResponse = client.search(s -> s.index("user_test").query(q -> q
9.                         .range(r -> r.field("age").gte(JsonData.of(20)).lt(JsonData.of(21))))
10.                 , User.class);
11.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
13.         transport.close();
14.         restClient.close();
15.     }

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含糊查询

1.     @Test
2.     public void fuzzyQueryDocument2() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 模糊查询，fuzziness表示差几个可以查询出来
8.         SearchResponse<User> searchResponse = client.search(s -> s.index("user_test").query(q -> q
9.                         .fuzzy(f -> f.field("name").value("tst").fuzziness("2")))
10.                 , User.class);
11.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
13.         transport.close();
14.         restClient.close();
15.     }

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高亮查询

1.     @Test
2.     public void highlightQueryDocument2() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 高亮查询
8.         SearchResponse<User> searchResponse = client.search(s -> s.index("user_test").query(q -> q
9.                         .term(t -> t.field("name").value("test3")))
10.                         .highlight(h -> h.fields("name", f -> f.preTags("<font color='red'>").postTags("</font>")))
11.                 , User.class);
12.         searchResponse.hits().hits().forEach(h -> System.out.println(h.source().toString()));
14.         transport.close();
15.         restClient.close();
16.     }

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聚合查询

1.     @Test
2.     public void aggregateQueryDocument2() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 聚合查询，取最大年龄
8.         SearchResponse<User> searchResponse = client.search(s -> s.index("user_test").aggregations("maxAge", a ->a.max(m -> m.field("age")))
9.                 , User.class);
10.         searchResponse.aggregations().entrySet().forEach(f -> System.out.println(f.getKey() + ":" + f.getValue().max().value()));
12.         transport.close();
13.         restClient.close();
14.     }

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分组查询

1.     @Test
2.     public void groupQueryDocument2() throws IOException {
3.         RestClient restClient = RestClient.builder(new HttpHost("localhost", 9200)).build();
4.         ElasticsearchTransport transport = new RestClientTransport(restClient, new JacksonJsonpMapper());
5.         ElasticsearchClient client = new ElasticsearchClient(transport);
7.         // 分组查询
8.         SearchResponse<User> searchResponse = client.search(s -> s.index("user_test")
9.                         .aggregations("ageGroup", a ->a.terms(t -> t.field("age")))
10.                 , User.class);
11.         searchResponse.aggregations().get("ageGroup").lterms().buckets().array().forEach(f -> System.out.println(f.key() + ":" + f.docCount()));
13.         transport.close();
14.         restClient.close();
15.     }

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