文章目录

ElasticSearch——Spring Boot 集成 ES 操作详解
- 1、SpringBoot 集成 ES
- 2、索引的API操作详解
- 3、文档的API操作详解

ElasticSearch——Spring Boot 集成 ES 操作详解

1、SpringBoot 集成 ES

1、新建一个Spring Boot 项目，添加 ElasticSearch 模块：

2、修改ES版本

可以看到，SpringBoot帮我们导入的ES版本是7.12.1：

而我们本地使用的版本是7.8.0，所以为了防止连接ES失败，要把版本号修改过成和本地一致。

<!-- 在pom.xml文件的properties属性下面添加： -->
<elasticsearch.version>7.8.0</elasticsearch.version>

一定要确保修改成功。

3、编写配置文件

package com.cheng;import org.apache.http.HttpHost;
import org.elasticsearch.client.RestClient;
import org.elasticsearch.client.RestHighLevelClient;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import org.springframework.data.elasticsearch.client.RestClients;@Configuration
public class ElasticSearchClientConfig {//配置RestHighLevelClient依赖到spring容器中待用@Beanpublic RestHighLevelClient restHighLevelClient(){RestHighLevelClient client = new RestHighLevelClient(RestClient.builder(//绑定本机，端口，协议，如果是ES集群，就配置多个new HttpHost("127.0.0.1",9200,"http")));return client;}
}

到这里，ElasticSearch和SpringBoot的集成就完成了，下面就是关于索引和文档API的使用。

Java REST Client

Java REST Client 有两种风格：

Java Low Level REST Client ：用于Elasticsearch的官方低级客户端。它允许通过http与Elasticsearch集群通信。将请求编排和响应反编排留给用户自己处理。它兼容所有的Elasticsearch版本。
Java High Level REST Client ：用于Elasticsearch的官方高级客户端。它是基于低级客户端的，它提供很多API，并负责请求的编排与响应的反编排。
官方更建议我们用Java High Level REST Client，它执行HTTP请求，而不是序列号的Java请求。

下面测试使用的是 Java 高级客户端。

2、索引的API操作详解

创建索引

    //创建索引测试@Testvoid contextLoads() throws IOException {//创建索引的请求CreateIndexRequest request = new CreateIndexRequest("wanli");//执行创建索引的请求，返回一个响应CreateIndexResponse response = client.indices().create(request, RequestOptions.DEFAULT);//打印响应System.out.println(response); //org.elasticsearch.client.indices.CreateIndexResponse@6ce3e00}

RestHighLevelClient中的所有API都接受RequestOptions，您可以使用该选项定制请求，而不会改变Elasticsearch执行请求的方式。例如，您可以在此处指定一个节点选择器来控制哪个节点接收请求。

判断索引是否存在

    //判断索引是否存在,存在返回true，不存在返回false@Testpublic void test1() throws IOException {GetIndexRequest request = new GetIndexRequest("wanli_index");boolean b = client.indices().exists(request, RequestOptions.DEFAULT);System.out.println(b); //true}

删除索引

    //删除索引@Testpublic void test2() throws IOException {DeleteIndexRequest request = new DeleteIndexRequest("wanli_index");AcknowledgedResponse response = client.indices().delete(request,RequestOptions.DEFAULT);System.out.println(response.isAcknowledged()); //返回true删除成功}

3、文档的API操作详解

添加文档

实体类：

@Component
@Data
@AllArgsConstructor
@NoArgsConstructor
public class User {private String name;private int age;
}

添加文档代码：

    @Testpublic void test3() throws IOException {User user = new User("万里", 3);//创建请求IndexRequest request = new IndexRequest("wanli_index");request.id("1")  //文档id，不指定会有默认id.timeout(TimeValue.timeValueSeconds(1))//分片超时时间.source(JSON.toJSONString(user), XContentType.JSON); //将文档源设置为索引，user对象转化成json字符串IndexResponse response = client.index(request, RequestOptions.DEFAULT);System.out.println(response.toString());        //IndexResponse[index=wanli_index,type=_doc,id=1,version=1,result=created,seqNo=0,primaryTerm=1,shards={"total":2,"successful":1,"failed":0}]       System.out.println(response.status());//CREATED 操作状态}

判断文档是否存在

    //判断文档是否存在@Testpublic void test4() throws IOException {//针对指定的索引和文档 ID 构造一个新的 get 请求GetRequest request = new GetRequest("wanli_index","1");String[] includes = Strings.EMPTY_ARRAY;String[] excludes = new String[]{"age"};//值获取 _source 中包含age的文档信息//fetchSourceContext指定需要返回字段的上下文,提供更加完善的过滤逻辑，主要特性为支持include、exclude和支持通篇符过滤。request.fetchSourceContext(new FetchSourceContext(true, includes, excludes));boolean b = client.exists(request, RequestOptions.DEFAULT);System.out.println(b); //true则存在}

获取文档信息

    //获取文档信息@Testpublic void test5() throws IOException {GetRequest request = new GetRequest("wanli_index", "1");GetResponse response = client.get(request, RequestOptions.DEFAULT);System.out.println(response.toString());//{"_index":"wanli_index","_type":"_doc","_id":"1","_version":1,"_seq_no":0,"_primary_term":1,"found":true,"_source":{"age":3,"name":"万里"}}System.out.println(response.getSource());//获取_source：{name=万里, age=3}System.out.println(response.getVersion());//1System.out.println(response);//{"_index":"wanli_index","_type":"_doc","_id":"1","_version":1,"_seq_no":0,"_primary_term":1,"found":true,"_source":{"age":3,"name":"万里"}}}

修改文档信息

    //修改文档信息@Testpublic void test6() throws IOException {UpdateRequest request = new UpdateRequest("wanli_index", "1");request.timeout("1s");User user = new User("神明", 18);//doc里面填具体的内容和文档格式request.doc(JSON.toJSONString(user),XContentType.JSON);UpdateResponse response = client.update(request, RequestOptions.DEFAULT);System.out.println(response.status()); //返回ok表示操作成功}

删除文档

    //删除文档@Testpublic void test7() throws IOException {DeleteRequest request = new DeleteRequest("wanli_index", "1");request.timeout("1s");DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);System.out.println(response.status());//返回ok表示操作成功}

批量插入文档

BulkRequest：批量请求包含有序的IndexRequest 、 DeleteRequest 和UpdateRequest ，并允许在单个批处理中执行它。请注意，我们仅支持批量请求而不是每个项目的刷新。

   //批量插入文档@Testpublic void test8() throws IOException {BulkRequest request = new BulkRequest();request.timeout("10s");ArrayList<User> list = new ArrayList<>();list.add(new User("shenming1",3));list.add(new User("shenming2",3));list.add(new User("shenming3",3));list.add(new User("shenming4",3));list.add(new User("shenming5",3));for (int i = 0; i < list.size(); i++) {request.add(new IndexRequest("wanli_index").id(""+(i+1)).source(JSON.toJSONString(list.get(i)),XContentType.JSON));}BulkResponse response = client.bulk(request, RequestOptions.DEFAULT);System.out.println(response.status()); //ok}

根据具体的需求调用下面的方法。

复杂查询操作

1、构建查询请求：SearchRequest request = new SearchRequest(“wanli_index”);

2、构建搜索条件：SearchSourceBuilder sourceBuilder = SearchSourceBuilder.searchSource();

3、将查询条件放入请求：request.source(sourceBuilder);

4、执行请求：SearchResponse response = client.search(request, RequestOptions.DEFAULT);

@Test
public void test9() throws IOException {//构建查询请求SearchRequest request = new SearchRequest("wanli_index");//构建搜索条件SearchSourceBuilder sourceBuilder = SearchSourceBuilder.searchSource();//设置高亮     //HighlightBuilder highlightBuilder = new HighlightBuilder();//highlightBuilder.field("name");//highlightBuilder.preTags("<span style='color:red'>");//highlightBuilder.postTags("</span>");//searchSourceBuilder.highlighter(highlightBuilder);//分页：//sourceBuilder.from(0);//sourceBuilder.size(10);//QueryBuilders 工具类实现查询条件的构建//QueryBuilders.termQuery 精确查询//QueryBuilders.matchAllQuery() 匹配所有TermQueryBuilder queryBuilder = QueryBuilders.termQuery("name", "shenming1");sourceBuilder.query(queryBuilder);//将精确查询条件放入搜索条件sourceBuilder.timeout(new TimeValue(60, TimeUnit.SECONDS));//设置超时时间//将查询条件放入请求request.source(sourceBuilder);//执行请求SearchResponse response = client.search(request, RequestOptions.DEFAULT);//打印搜索命中文档结果System.out.println(JSON.toJSONString(response.getHits()));//{"fragment":true,"hits":[{"fields":{},"fragment":false,"highlightFields":{},"id":"1","matchedQueries":[],"primaryTerm":0,"rawSortValues":[],"score":1.1727202,"seqNo":-2,"sortValues":[],"sourceAsMap":{"name":"shenming1","age":3},"sourceAsString":"{\"age\":3,\"name\":\"shenming1\"}","sourceRef":{"fragment":true},"type":"_doc","version":-1}],"maxScore":1.1727202,"totalHits":{"relation":"EQUAL_TO","value":1}}System.out.println("====================================");for (SearchHit searchHit : response.getHits().getHits()) {System.out.println(searchHit.getSourceAsMap());//{name=shenming1, age=3}}}