Elasticsearch rest-high-level-client 基本操作
本篇次要解说一下 rest-high-level-client 去操作 Elasticsearch , 尽管这个客户端在后续版本中会缓缓淘汰,然而目前大部分公司中应用Elasticsearch 版本都是6.x 所以这个客户端还是有肯定的理解
前置筹备
- 筹备一个SpringBoot环境 2.2.11 版本
- 筹备一个Elasticsearch 环境 我这里是8.x版本
- 引入依赖 elasticsearch-rest-high-level-client 7.4.2
1.配置依赖
留神: 我应用的是 springboot 2.2.11 版本 , 它外部的 elasticsearch 和 elasticsearch-rest-client 都是 6.8.13 须要留神
<dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-web</artifactId> </dependency> <dependency> <groupId>org.projectlombok</groupId> <artifactId>lombok</artifactId> <optional>true</optional> </dependency> <dependency> <groupId>org.springframework.boot</groupId> <artifactId>spring-boot-starter-test</artifactId> <scope>test</scope> </dependency> <!-- 引入 elasticsearch 7.4.2 --> <dependency> <groupId>org.elasticsearch</groupId> <artifactId>elasticsearch</artifactId> <version>7.4.2</version> <exclusions> <exclusion> <artifactId>log4j-api</artifactId> <groupId>org.apache.logging.log4j</groupId> </exclusion> </exclusions> </dependency> <!-- 排除 elasticsearch-rest-client , 也可不排除 为了把maven抵触解决 --> <dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-high-level-client</artifactId> <version>7.4.2</version> <exclusions> <exclusion> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-client</artifactId> </exclusion> <exclusion> <artifactId>elasticsearch</artifactId> <groupId>org.elasticsearch</groupId> </exclusion> </exclusions> </dependency> <!-- 不引入会导致可能 应用 springboot的 elasticsearch-rest-client 6.8.13 --> <dependency> <groupId>org.elasticsearch.client</groupId> <artifactId>elasticsearch-rest-client</artifactId> <version>7.4.2</version> </dependency> <!-- elasticsearch 依赖 2.x 的 log4j --> <dependency> <groupId>org.apache.logging.log4j</groupId> <artifactId>log4j-core</artifactId> <version>2.8.2</version> <!-- 排除掉 log4j-api 因为springbootstarter 中引入了loging模块 --> <exclusions> <exclusion> <artifactId>log4j-api</artifactId> <groupId>org.apache.logging.log4j</groupId> </exclusion> </exclusions> </dependency> <!-- junit 单元测试 --> <dependency> <groupId>junit</groupId> <artifactId>junit</artifactId> <version>4.12</version> </dependency>2.构建 RestHighLevelClient
highlevelclient 是 高级客户端 须要通过它去操作 Elasticsearch , 它底层也是要依赖 rest-client 低级客户端
@Slf4jpublic class TestEsClient { private RestHighLevelClient client = null; private ObjectMapper objectMapper = new ObjectMapper(); //构建 RestHighLevelClient @Before public void prepare() { // 创立Client连贯对象 String[] ips = {"172.16.225.111:9200"}; HttpHost[] httpHosts = new HttpHost[ips.length]; for (int i = 0; i < ips.length; i++) { httpHosts[i] = HttpHost.create(ips[i]); } RestClientBuilder builder = RestClient.builder(httpHosts); client = new RestHighLevelClient(builder); }}3.创立索引 client.indices().create
创立索引 须要应用 CreateIndexRequest 对象 , 操作 索引基本上是 client.indices().xxx
构建 CreateIndexRequest 对象
@Testpublic void test1() { CreateIndexRequest request = new CreateIndexRequest("blog1"); try { CreateIndexResponse createIndexResponse = client.indices().create(request, RequestOptions.DEFAULT); boolean acknowledged = createIndexResponse.isAcknowledged(); log.info("[create index blog :{}]", acknowledged); } catch (IOException e) { e.printStackTrace(); }}4.删除索引 client.indices().delete
构建 DeleteIndexRequest 对象
@Testpublic void testDeleteIndex(){ DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest("blog1"); try { AcknowledgedResponse response = client.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT); log.info("[delete index response: {}", response.isAcknowledged()); } catch (IOException e) { e.printStackTrace(); }}4.查问索引 client.indices().get
构建 GetIndexRequest 对象
@Testpublic void testSearchIndex() { GetIndexRequest request = new GetIndexRequest("blog1"); try { GetIndexResponse getIndexResponse = client.indices().get(request, RequestOptions.DEFAULT); Map<String, List<AliasMetaData>> aliases = getIndexResponse.getAliases(); Map<String, MappingMetaData> mappings = getIndexResponse.getMappings(); Map<String, Settings> settings = getIndexResponse.getSettings(); log.info("[aliases: {}]", aliases); log.info("[mappings: {}]", mappings); log.info("[settings: {}", settings); } catch (IOException e) { e.printStackTrace(); }}能够依据 response 获取 aliases , mappings , settings 等等 和 Kibana 中返回的一样
5.插入文档 client.index
插入文档 须要应用 IndexRequest 对象 , 留神 不是 InsertRequest , 不晓得为什么不这样定义 感觉会更加好了解
request.source(blogInfoJsonStr, XContentType.JSON);
@Testpublic void insertDoc() { IndexRequest request = new IndexRequest(); request.index("blog1").id("1"); BlogInfo blogInfo = new BlogInfo() .setBlogName("Elasticsearch 入门第一章") .setBlogType("Elasticsearch") .setBlogDesc("本篇次要介绍了Elasticsearch 的根本client操作"); try { //提供java 对象的 json str String blogInfoJsonStr = objectMapper.writeValueAsString(blogInfo); request.source(blogInfoJsonStr, XContentType.JSON); // 这里会抛错 起因是 我的 Elasticsearch 版本8.x 而 应用的 restHighLevel 曾经解析不了,因为新的es曾经不举荐应用 // restHighLevel,而应用 Elasticsearch Java API Client IndexResponse index = client.index(request, RequestOptions.DEFAULT); log.info("[Result insert doc :{} ]", index); } catch (IOException e) { }}6.查问文档 client.get
留神 getResponse.getSourceAsString() 返回文档数据
@Testpublic void testSelectDoc() { GetRequest getRequest = new GetRequest(); getRequest.index("blog1").id("1"); try { GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT); BlogInfo blogInfo = objectMapper.readValue(getResponse.getSourceAsString(), BlogInfo.class); log.info("[get doc :{}] ", blogInfo); } catch (IOException e) { e.printStackTrace(); }}7.删除文档 client.delete
留神 删除文档 的 response 也解析不了 Elasticsearch 8.x 版本
@Testpublic void testDeleteDoc() { DeleteRequest deleteRequest = new DeleteRequest(); deleteRequest.index("blog1").id("1"); try { // 这里也会抛错 和下面的一样 DeleteResponse deleteResponse = client.delete(deleteRequest, RequestOptions.DEFAULT); log.info("[delete response:{} ]", deleteResponse); } catch (IOException e) { }}总结
本篇次要介绍了 java 操作Elasticsearch 的客户端 rest-high-level-client 的根本应用 , 如果你是应用springboot 须要留神jar 抵触问题, 后续操作 Elasticsearch 客户端 逐步变成 Elasticsearch Java API Client , 不过目前大部分还是应用 rest-high-level-client
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