1 SpringBoot整合ElasticSearch

1.1 pom依赖和版本关系

1.1.1 pom.xml

导入elasticsearch依赖，在pom.xml里加入如下依赖

      org.springframework.boot
      spring-boot-starter-data-elasticsearch

注意：检查依赖版本是否与前所用的版本是否一致，如果不一致，会连接失败

image.png

1.1.2 版本关系

SpringBoot 版本问题，SpringBoot 的版本对应不上ES的版本

由于以上ElasticSearch 版本之间的差距导致对应Spring Data ElasticSearch包的差距；所以在不降低 Spring Boot 版本的情况需兼容低版本的 ElasticSearch 的客户端。

解决方法：

• 方案一
  由于不兼容，即放弃 Spring Data ElasticSearch 框架包，使用最直接的 Java ElasticSearch Client 连接即可，将 Client 注入到 Spring 容器中，使用High/Low Level Client API连接也是可以的（HighLevel 是在 LowLevel Client 的基础上封装而成的）
  点击查看JavaAPI操作ES
• 方案二
  由于 SpringBoot 2.3.x 以上版本只支持 ES7 服务，所以对于一些本身为SpringBoot 高版本的项目而言单纯的引入spring-boot-starter-data-elasticsearch 模块包是存在兼容性问题的，所以需要将 Spring Data ElasticSearch 单独引入，由于ES6对应的 Spring Data ElasticSearch 为3.2.x 版本

1.2 创建高级客户端

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;

@Configuration
public class ElasticSearchClientConfig {
    @Bean
    public RestHighLevelClient restHighLevelClient(){
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("服务器IP", 9200, "http")));
        return client;
    }
}

1.3 基本用法

1.3.1 创建、判断存在、删除索引

import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestHighLevelClient;
import org.elasticsearch.client.indices.CreateIndexRequest;
import org.elasticsearch.client.indices.CreateIndexResponse;
import org.elasticsearch.client.indices.GetIndexRequest;
import org.junit.jupiter.api.Test;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.boot.test.context.SpringBootTest;

import java.io.IOException;

@SpringBootTest
public class ElasticsearchApplicationTests {

 @Autowired
 private RestHighLevelClient restHighLevelClient;

 @Test
 void testCreateIndex() throws IOException {
  //1.创建索引请求
  CreateIndexRequest request = new CreateIndexRequest("ljx666");
  //2.客户端执行请求IndicesClient，执行create方法创建索引，请求后获得响应
  CreateIndexResponse response=
    restHighLevelClient.indices().create(request, RequestOptions.DEFAULT);
  System.out.println(response);
 }

 @Test
 void testExistIndex() throws IOException {
        //1.查询索引请求
  GetIndexRequest request=new GetIndexRequest("ljx666");
        //2.执行exists方法判断是否存在
  boolean exists=restHighLevelClient.indices().exists(request,RequestOptions.DEFAULT);
  System.out.println(exists);
 }

 @Test
 void testDeleteIndex() throws IOException {
        //1.删除索引请求
  DeleteIndexRequest request=new DeleteIndexRequest("ljx666");
        //执行delete方法删除指定索引
  AcknowledgedResponse delete = restHighLevelClient.indices().delete(request, RequestOptions.DEFAULT);
  System.out.println(delete.isAcknowledged());
 }

}

1.3.2 对文档的CRUD

创建文档
注意：如果添加时不指定文档ID，他就会随机生成一个ID，ID唯一。
创建文档时若该ID已存在，发送创建文档请求后会更新文档中的数据。

@Test
void testAddUser() throws IOException {
 //1.创建对象
 User user=new User("Go",21,new String[]{"内卷","吃饭"});
 //2.创建请求
 IndexRequest request=new IndexRequest("ljx666");
 //3.设置规则 PUT /ljx666/_doc/1
 //设置文档id=6，设置超时=1s等，不设置会使用默认的
 //同时支持链式编程如 request.id("6").timeout("1s");
 request.id("6");
 request.timeout("1s");

 //4.将数据放入请求，要将对象转化为json格式
    //XContentType.JSON，告诉它传的数据是JSON类型
 request.source(JSONValue.toJSONString(user), XContentType.JSON);
    
 //5.客户端发送请求，获取响应结果
 IndexResponse indexResponse=restHighLevelClient.index(request,RequestOptions.DEFAULT);
 System.out.println(indexResponse.toString());
 System.out.println(indexResponse.status());
}

获取文档中的数据：

@Test
void testGetUser() throws IOException {
 //1.创建请求,指定索引、文档id
 GetRequest request=new GetRequest("ljx666","1");
 GetResponse getResponse=restHighLevelClient.get(request,RequestOptions.DEFAULT);
  
 System.out.println(getResponse);//获取响应结果
 //getResponse.getSource() 返回的是Map集合
 System.out.println(getResponse.getSourceAsString());//获取响应结果source中内容，转化为字符串
  
}

更新文档数据:
注意：需要将User对象中的属性全部指定值，不然会被设置为空，如User只设置了名称，那么只有名称会被修改成功，其他会被修改为null。

@Test
void testUpdateUser() throws IOException {
 //1.创建请求,指定索引、文档id
 UpdateRequest request=new UpdateRequest("ljx666","6");

 User user =new User("GoGo",21,new String[]{"内卷","吃饭"});
 //将创建的对象放入文档中
 request.doc(JSONValue.toJSONString(user),XContentType.JSON);

 UpdateResponse updateResponse=restHighLevelClient.update(request,RequestOptions.DEFAULT);
 System.out.println(updateResponse.status());//更新成功返回OK
}

删除文档:

@Test
void testDeleteUser() throws IOException {
 //创建删除请求，指定要删除的索引与文档ID
 DeleteRequest request=new DeleteRequest("ljx666","6");

 DeleteResponse updateResponse=restHighLevelClient.delete(request,RequestOptions.DEFAULT);
 System.out.println(updateResponse.status());//删除成功返回OK，没有找到返回NOT_FOUND
}

1.3.3 批量CRUD数据

这里只列出了批量插入数据，其他与此类似

注意：hasFailures()方法是返回是否失败，即它的值为false时说明上传成功

@Test
void testBulkAddUser() throws IOException {
 BulkRequest bulkRequest=new BulkRequest();
 //设置超时
 bulkRequest.timeout("10s");

 ArrayList list=new ArrayList<>();
 list.add(new User("Java",25,new String[]{"内卷"}));
 list.add(new User("Go",18,new String[]{"内卷"}));
 list.add(new User("C",30,new String[]{"内卷"}));
 list.add(new User("C++",26,new String[]{"内卷"}));
 list.add(new User("Python",20,new String[]{"内卷"}));

 int id=1;
 //批量处理请求
 for (User u :list){
  //不设置id会生成随机id
  bulkRequest.add(new IndexRequest("ljx666")
    .id(""+(id++))
    .source(JSONValue.toJSONString(u),XContentType.JSON));
 }

 BulkResponse bulkResponse=restHighLevelClient.bulk(bulkRequest,RequestOptions.DEFAULT);
 System.out.println(bulkResponse.hasFailures());//是否执行失败,false为执行成功
}

1.3.4 查询所有、模糊查询、分页查询、排序、高亮显示

@Test
void testSearch() throws IOException {
 SearchRequest searchRequest=new SearchRequest("ljx666");//里面可以放多个索引
 SearchSourceBuilder sourceBuilder=new SearchSourceBuilder();//构造搜索条件

 //此处可以使用QueryBuilders工具类中的方法
 //1.查询所有
 sourceBuilder.query(QueryBuilders.matchAllQuery());
 //2.查询name中含有Java的
 sourceBuilder.query(QueryBuilders.multiMatchQuery("java","name"));
 //3.分页查询
 sourceBuilder.from(0).size(5);
    
 //4.按照score正序排列
 //sourceBuilder.sort(SortBuilders.scoreSort().order(SortOrder.ASC));
 //5.按照id倒序排列（score会失效返回NaN）
 //sourceBuilder.sort(SortBuilders.fieldSort("_id").order(SortOrder.DESC));

 //6.给指定字段加上指定高亮样式
 HighlightBuilder highlightBuilder=new HighlightBuilder();
 highlightBuilder.field("name").preTags("").postTags("");
 sourceBuilder.highlighter(highlightBuilder);
  
 searchRequest.source(sourceBuilder);
 SearchResponse searchResponse=restHighLevelClient.search(searchRequest,RequestOptions.DEFAULT);

 //获取总条数
 System.out.println(searchResponse.getHits().getTotalHits().value);
 //输出结果数据（如果不设置返回条数，大于10条默认只返回10条）
 SearchHit[] hits=searchResponse.getHits().getHits();
 for(SearchHit hit :hits){
  System.out.println("分数:"+hit.getScore());
  Map source=hit.getSourceAsMap();
  System.out.println("index->"+hit.getIndex());
  System.out.println("id->"+hit.getId());
  for(Map.Entry s:source.entrySet()){
   System.out.println(s.getKey()+"--"+s.getValue());
  }
 }
}

1.4 高阶用法

1.4.1 精确查询

1.4.1.1 单条件精确查询

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 单条件精确查询
     * @throws IOException
     */
    @Test
    public void search0() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.termsQuery("name", "赵里"));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }

}

1.4.1.2 根据 id 精确匹配

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 根据id精确匹配
     * @throws IOException
     */
    @Test
    public void searchById() throws IOException {
        String[] ids = new String[]{"1","2"};
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.termsQuery("_id", ids));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.2 多条件精确查询，取并集

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 多条件精确查询，取并集
     * @throws IOException
     */
    @Test
    public void search1() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.termsQuery("name", "张", "陈"));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.3 范围查询

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 范围查询，包括from、to
     * @throws IOException
     */
    @Test
    public void search2() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.rangeQuery("age").from(20).to(32));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }


    /**
     * 范围查询，不包括from、to
     * @throws IOException
     */
    @Test
    public void search3() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.rangeQuery("age").from(20,false).to(30, false));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }


    /**
     * 范围查询, lt:小于，gt:大于
     * @throws IOException
     */
    @Test
    public void search4() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.rangeQuery("age").lt(30).gt(20));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.4 模糊查询，支持通配符

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 模糊查询，支持通配符
     * @throws IOException
     */
    @Test
    public void search5() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.wildcardQuery("name","张三"));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }

}

1.4.5 不使用通配符的模糊查询，左右匹配

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 不使用通配符的模糊查询，左右匹配
     * @throws IOException
     */
    @Test
    public void search6() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.queryStringQuery("张三").field("name"));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.6 多字段模糊查询

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 多字段模糊查询
     * @throws IOException
     */
    @Test
    public void search7() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.multiMatchQuery("长", "name", "city"));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.7 分页+排序 查询

1.4.7.1 分页

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 分页搜索
     * @throws IOException
     */
    @Test
    public void search8() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .from(0).size(2);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }

}

1.4.7.2 排序查询

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 排序，字段的类型必须是：integer、double、long或者keyword
     * @throws IOException
     */
    @Test
    public void search9() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .sort("createTime", SortOrder.ASC);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }

}

1.4.7.3 分页+排序

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 多条件查询 + 排序 + 分页
     * @throws IOException
     */
    @Test
    public void search29() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        //条件搜索
        BoolQueryBuilder boolQueryBuilder=new BoolQueryBuilder();
        boolQueryBuilder.must(QueryBuilders.matchQuery("name", "张王"));
        boolQueryBuilder.must(QueryBuilders.rangeQuery("age").lte(30).gte(20));
        builder.query(boolQueryBuilder);

        //结果集合分页
        builder.from(0).size(2);

        //排序
        builder.sort("createTime",SortOrder.ASC);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.8 精确统计筛选文档数

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 精确统计筛选文档数,查询性能有所降低
     * @throws IOException
     */
    @Test
    public void search10() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .trackTotalHits(true);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }

}

1.4.9 设置源字段过滤返回

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 设置源字段过虑,第一个参数结果集包括哪些字段，第二个参数表示结果集不包括哪些字段
     * @throws IOException
     */
    @Test
    public void search11() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .fetchSource(new String[]{"name","age","city","createTime"},new String[]{});

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.10 match 搜索匹配

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * match搜索匹配
     * @throws IOException
     */
    @Test
    public void search22() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder()
                .query(QueryBuilders.matchQuery("name", "张王"));

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.11 bool组合查询

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * bool组合查询
     * @throws IOException
     */
    @Test
    public void search23() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        BoolQueryBuilder boolQueryBuilder=new BoolQueryBuilder();
        boolQueryBuilder.must(QueryBuilders.matchQuery("name", "张王"));
        boolQueryBuilder.must(QueryBuilders.rangeQuery("age").lte(30).gte(20));
        builder.query(boolQueryBuilder);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.12 nested 类型嵌套查询

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * nested类型嵌套查询
     * @throws IOException
     */
    @Test
    public void search24() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        //条件查询
        BoolQueryBuilder mainBool=new BoolQueryBuilder();
        mainBool.must(QueryBuilders.matchQuery("name", "赵六"));

        //nested类型嵌套查询
        BoolQueryBuilder boolQueryBuilder=new BoolQueryBuilder();
        boolQueryBuilder.must(QueryBuilders.matchQuery("products.brand", "A"));
        boolQueryBuilder.must(QueryBuilders.matchQuery("products.title", "巧克力"));
        NestedQueryBuilder nested = QueryBuilders.nestedQuery("products",boolQueryBuilder, ScoreMode.None);
        mainBool.must(nested);

        builder.query(mainBool);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.13 聚合查询

1.4.13.1 求和

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 聚合查询 sum
     * @throws IOException
     */
    @Test
    public void search30() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        //条件搜索
        builder.query(QueryBuilders.matchAllQuery());
        //聚合查询
        AggregationBuilder aggregation = AggregationBuilders.sum("sum_age").field("age");
        builder.aggregation(aggregation);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.13.2 求平均值

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 聚合查询 avg
     * @throws IOException
     */
    @Test
    public void search31() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        //条件搜索
        builder.query(QueryBuilders.matchAllQuery());
        //聚合查询
        AggregationBuilder aggregation = AggregationBuilders.avg("avg_age").field("age");
        builder.aggregation(aggregation);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.13.3 计数

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 聚合查询 count
     * @throws IOException
     */
    @Test
    public void search32() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        //条件搜索
        builder.query(QueryBuilders.matchAllQuery());
        //聚合查询
        AggregationBuilder aggregation = AggregationBuilders.count("count_age").field("age");
        builder.aggregation(aggregation);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

1.4.13.4 分组

@RunWith(SpringJUnit4ClassRunner.class)
@SpringBootTest(classes = ElasticSearchApplication.class)
public class SearchJunit {

    @Autowired
    private RestHighLevelClient client;

    /**
     * 聚合查询 分组
     * @throws IOException
     */
    @Test
    public void search33() throws IOException {
        // 创建请求
        SearchSourceBuilder builder = new SearchSourceBuilder();

        //条件搜索
        builder.query(QueryBuilders.matchAllQuery());
        //聚合查询
        AggregationBuilder aggregation = AggregationBuilders.terms("tag_createTime").field("createTime")
                .subAggregation(AggregationBuilders.count("count_age").field("age")) //计数
                .subAggregation(AggregationBuilders.sum("sum_age").field("age")) //求和
                .subAggregation(AggregationBuilders.avg("avg_age").field("age")); //求平均值

        builder.aggregation(aggregation);

        //不输出原始数据
        builder.size(0);

        //搜索
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("cs_index");
        searchRequest.types("_doc");
        searchRequest.source(builder);
        // 执行请求
        SearchResponse response = client.search(searchRequest, RequestOptions.DEFAULT);
        // 解析查询结果
        System.out.println(response.toString());
    }
}

参考链接：https://mp.weixin.qq.com/s/F-eleu11MZLDiGpHfECdRg

1.5 总结

1. 大致流程
   创建对应的请求 --> 设置请求（添加规则，添加数据等） --> 执行对应的方法（传入请求，默认请求选项）–> 接收响应结果（执行方法返回值）–> 输出响应结果中需要的数据（source，status等）
2. 注意事项
   如果不指定id，会自动生成一个随机id
   正常情况下，不应该这样使用new IndexRequest(“ljx777”)，如果索引发生改变了，那么代码都需要修改，可以定义一个枚举类或者一个专门存放常量的类，将变量用final static等进行修饰，并指定索引值。其他地方引用该常量即可，需要修改也只需修改该类即可。
   elasticsearch相关的东西，版本都必须一致，不然会报错
   elasticsearch很消耗内存，建议在内存较大的服务器上运行elasticsearch，否则会因为内存不足导致elasticsearch自动killed

转载于：https://mp.weixin.qq.com/s/G8x18bvHQz60gGu1YiRJ5w