Elasticsearch7.8.0版本入门——JavaAPI操作（分页查询文档）

Posted 2023-02-05 小志的博客

目录

• • 一、pom文件依赖
  • 二、首先，批量创建文档（添加假数据，方便查询操作）
  • 三、分页查询文档 代码示例

一、pom文件依赖

• 引入相关依赖

  <!-- elasticsearch 依赖 -->
  <dependency>
      <groupId>org.elasticsearch</groupId>
      <artifactId>elasticsearch</artifactId>
      <version>7.8.0</version>
  </dependency>
  <!-- elasticsearch 的客户端 -->
  <dependency>
      <groupId>org.elasticsearch.client</groupId>
      <artifactId>elasticsearch-rest-high-level-client</artifactId>
      <version>7.8.0</version>
  </dependency>
  <!-- elasticsearch 依赖 2.x 的 log4j -->
  <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-api</artifactId>
      <version>2.8.2</version>
  </dependency>
  <dependency>
      <groupId>org.apache.logging.log4j</groupId>
      <artifactId>log4j-core</artifactId>
      <version>2.8.2</version>
  </dependency>
  <dependency>
      <groupId>com.fasterxml.jackson.core</groupId>
      <artifactId>jackson-databind</artifactId>
      <version>2.9.9</version>
  </dependency>
  <!-- junit 单元测试 -->
  <dependency>
      <groupId>junit</groupId>
      <artifactId>junit</artifactId>
      <version>4.12</version>
  </dependency>
  <dependency>
      <groupId>org.projectlombok</groupId>
      <artifactId>lombok</artifactId>
  </dependency>
  

二、首先，批量创建文档（添加假数据，方便查询操作）

• 参考此博文链接：https://wwwxz.blog.csdn.net/article/details/128824820

三、分页查询文档 代码示例

• 分页查询文档代码示例

  package com.xz.esdemo.day4;
  
  import org.apache.http.HttpHost;
  import org.elasticsearch.action.search.SearchRequest;
  import org.elasticsearch.action.search.SearchResponse;
  import org.elasticsearch.client.RequestOptions;
  import org.elasticsearch.client.RestClient;
  import org.elasticsearch.client.RestHighLevelClient;
  import org.elasticsearch.index.query.QueryBuilders;
  import org.elasticsearch.search.SearchHit;
  import org.elasticsearch.search.SearchHits;
  import org.elasticsearch.search.builder.SearchSourceBuilder;
  
  /**
   * @description: 分页查询文档
   * @author: xz
   */
  public class EsDocPageQuery 
      public static void main(String[] args) throws Exception
          // 创建 es 客户端对象
          RestHighLevelClient client = new RestHighLevelClient(
                  RestClient.builder(new HttpHost("localhost", 9200, "http"))
          );
  
          // 创建搜索请求对象
          SearchRequest request = new SearchRequest();
          request.indices("user");
          // 构建查询的请求体
          SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
          // 查询所有文档数据
          sourceBuilder.query(QueryBuilders.matchAllQuery());
          // 当前页其实索引(第一条数据的顺序号) from
          sourceBuilder.from(0);
          // 每页显示多少条 size
          sourceBuilder.size(2);
  
          request.source(sourceBuilder);
  
          SearchResponse response = client.search(request, RequestOptions.DEFAULT);
  
          SearchHits hits = response.getHits();
          System.out.println("耗时====>took:" + response.getTook());
          System.out.println("超时时间====>timeout:" + response.isTimedOut());
          System.out.println("总数量====>total:" + hits.getTotalHits());
          System.out.println("最大分值====>MaxScore:" + hits.getMaxScore());
          for (SearchHit hit : hits) 
              //输出每条查询的结果信息
              System.out.println(hit.getSourceAsString());
          
          // 关闭 es 客户端连接
          client.close();
      
  
  

• 执行代码，查看控制台信息，如下图表示分页查询文档成功。
  

• 通过postman工具分页查询文档信息，如下图所示：