ElasticSearch-基础

ElasticSearch

Elastic Stack 包括 Elasticsearch、Kibana、Beats、Logstash。能够安全可靠的获取任何来源、任何格式的数据，然后实时的对数据进行搜索、分析、可视化。

ES 是一个开源的高扩展的分布式的全文搜索引擎，是整个 Elastic Stack 技术栈的核心。它可以近乎实时的存储、检索数据；本身扩展性很好，可以扩展到上百台服务器，处理 PB 级别的数据。

Lucene

Lucene 提供了一个简单却强大的应用程式接口，能够做全文索引和搜索。在 Java 开发环境里 Lucene 是一个成熟的、免费开源工具。但 Lucene 只是一个提供全文搜索功能类库的核心工具包，而真正使用它还需要一个完善的服务框架搭建起来进行应用。

数据格式

ES 是面向文档型数据库，一条数据相当于一个文档。

HTTP操作

• 创建索引

  http://localhost:9200/shopping [PUT]

• 创建文档

  http://localhost:9200/shopping/_doc [POST]

• 根据 ID 查询

  http://localhost:9200/shopping/_doc/[ID] [GET]

• 查询所有

  http://localhost:9200/shopping/_search [GET]

• 根据 ID 全量数据更新

  http://localhost:9200/shopping/_doc/[ID] [PUT]

• 根据 ID 局部数据更新

  http://localhost:9200/shopping/_update/[ID] [POST]

• 根据 ID 删除

  http://localhost:9200/shopping/_doc/[ID] [DELETE]

• 条件查询

  http://localhost:9200/shopping/_search?q=name:zh [GET]
  ​
  或者
  ​
  http://localhost:9200/shopping/_search [GET]
  {
      "query" : {
          "match" : {
              "name" : "zh"
          }
      } 
  }
  ​
  http://localhost:9200/shopping/_search [GET]
  {
      "query" : {
          "bool" : {
              "must" : [{
                  "match" : {
                      "name" : "zh"
                  }
              }]
          }
      } 
  }
  ​
  // 完全匹配
  {
      "query" : {
          "match_phrase" : {
              "name" : "zh"
          }
      }
  }
  ​
  // 聚合
  {
      "aggs" : { // 聚合操作
          "price_group" : { // 分组名称
              "terms" : { // 分组
                  "filed" : "price" // 分组字段
              }
          }
      }，
      "size" : 0 // 不需要返回原始数据
  }
  ​
  // 平均值
  {
      "aggs" : { // 聚合操作
          "price_avg" : { // 分组名称
              "avg" : { // 平均值
                  "filed" : "price" // 分组字段
              }
          }
      }，
      "size" : 0 // 不需要返回原始数据
  }

• 分页查询

  http://localhost:9200/shopping/_search
  {
      "query" : {
          "match_all" : {
          }
      } ,
      "from" : 0,
      "size" : 3
  }

• 指定参数查询

  http://localhost:9200/shopping/_search
  {
      "query" : {
          "match_all" : {
          }
      } ,
      "_source" : ["name"]
  }

• 查询结果排序

  http://localhost:9200/shopping/_search
  {
      "query" : {
          "match_all" : {
          }
      } ,
      "sort" : {
          "price" : {
              "order" : "asc"
          }
      }
  }

• 建立映射

  http://localhost:9200/user/_mapping [PUT]
  {
      "properties" : {
          "name" : {
              "type" : "text",
              "index" : true
          },
          "sex" : {
              "type" : "keyword",
              "index" : true
          },
          "tel" : {
              "type" : "keyword",
              "index" : false
          }
      }
  }

API 使用

import java.io.IOException;
​
import org.apache.http.HttpHost;
import org.elasticsearch.action.admin.indices.delete.DeleteIndexRequest;
import org.elasticsearch.action.bulk.BulkRequest;
import org.elasticsearch.action.bulk.BulkResponse;
import org.elasticsearch.action.delete.DeleteRequest;
import org.elasticsearch.action.delete.DeleteResponse;
import org.elasticsearch.action.get.GetRequest;
import org.elasticsearch.action.get.GetResponse;
import org.elasticsearch.action.index.IndexRequest;
import org.elasticsearch.action.index.IndexResponse;
import org.elasticsearch.action.search.SearchRequest;
import org.elasticsearch.action.search.SearchResponse;
import org.elasticsearch.action.support.master.AcknowledgedResponse;
import org.elasticsearch.action.update.UpdateRequest;
import org.elasticsearch.action.update.UpdateResponse;
import org.elasticsearch.client.RequestOptions;
import org.elasticsearch.client.RestClient;
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.elasticsearch.client.indices.GetIndexResponse;
import org.elasticsearch.common.unit.Fuzziness;
import org.elasticsearch.common.xcontent.XContentType;
import org.elasticsearch.index.query.BoolQueryBuilder;
import org.elasticsearch.index.query.FuzzyQueryBuilder;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.index.query.RangeQueryBuilder;
import org.elasticsearch.index.query.TermQueryBuilder;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.SearchHits;
import org.elasticsearch.search.aggregations.AggregationBuilder;
import org.elasticsearch.search.aggregations.AggregationBuilders;
import org.elasticsearch.search.aggregations.metrics.MaxAggregationBuilder;
import org.elasticsearch.search.builder.SearchSourceBuilder;
import org.elasticsearch.search.fetch.subphase.highlight.HighlightBuilder;
import org.elasticsearch.search.sort.SortOrder;
​
import com.fasterxml.jackson.databind.ObjectMapper;
​
/**
 * @author zhanghui07 
 * Created on 2021-09-16
 * @description：
 */
public class Test {
​
    private void creat(RestHighLevelClient esClient) throws IOException {
        System.out.println("创建索引");
        CreateIndexRequest createIndexRequest = new CreateIndexRequest("user");
        CreateIndexResponse createIndexResponse = esClient.indices().create(createIndexRequest, RequestOptions.DEFAULT);
        boolean acknowledged = createIndexResponse.isAcknowledged();
        System.out.println(acknowledged);
    }
​
    private void get(RestHighLevelClient esClient) throws IOException {
        System.out.println("获取索引");
        GetIndexRequest getIndexRequest = new GetIndexRequest("person");
        GetIndexResponse getIndexResponse = esClient.indices().get(getIndexRequest, RequestOptions.DEFAULT);
        System.out.println(getIndexResponse.getAliases());
        System.out.println(getIndexResponse.getMappings());
        System.out.println(getIndexResponse.getSettings());
    }
​
    private void del(RestHighLevelClient esClient) throws IOException {
        System.out.println("删除索引");
        DeleteIndexRequest deleteIndexRequest = new DeleteIndexRequest("user");
        AcknowledgedResponse delete = esClient.indices().delete(deleteIndexRequest, RequestOptions.DEFAULT);
        System.out.println(delete.isAcknowledged());
    }
​
    private void add(RestHighLevelClient esClient) throws IOException {
        System.out.println("插入数据");
        IndexRequest indexRequest = new IndexRequest();
        indexRequest.index("user").id("1007");
        User user = new User("wangwu4", 30, "男");
        ObjectMapper objectMapper = new ObjectMapper();
        String string = objectMapper.writeValueAsString(user);
        indexRequest.source(string, XContentType.JSON);
        IndexResponse response = esClient.index(indexRequest, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
    }
​
    private void update(RestHighLevelClient esClient) throws IOException {
        System.out.println("修改数据");
        UpdateRequest updateRequest = new UpdateRequest();
        updateRequest.index("user").id("1001");
        updateRequest.doc(XContentType.JSON, "sex", "女");
        UpdateResponse updateResponse = esClient.update(updateRequest, RequestOptions.DEFAULT);
        System.out.println(updateResponse.getResult());
    }
​
    private void getDoc(RestHighLevelClient esClient) throws IOException {
        System.out.println("查询数据");
        GetRequest getRequest = new GetRequest();
        getRequest.index("user").id("1001");
        GetResponse response = esClient.get(getRequest, RequestOptions.DEFAULT);
        System.out.println(response.getSourceAsString());
    }
​
    private void delDoc(RestHighLevelClient esClient) throws IOException {
        System.out.println("删除数据");
        DeleteRequest deleteRequest = new DeleteRequest();
        deleteRequest.index("user").id("1001");
        DeleteResponse response = esClient.delete(deleteRequest, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
    }
​
    private void batchAdd(RestHighLevelClient esClient) throws IOException {
        System.out.println("批量插入数据");
        BulkRequest bulkRequest = new BulkRequest();
        bulkRequest.add(new IndexRequest().index("user").id("1001")
                .source(XContentType.JSON, "name", "zhangsan", "age", 30, "sex", "男"));
        bulkRequest.add(new IndexRequest().index("user").id("1002")
                .source(XContentType.JSON, "name", "lisi", "age", 30, "sex", "女"));
        bulkRequest.add(new IndexRequest().index("user").id("1003")
                .source(XContentType.JSON, "name", "wangwu", "age", 40, "sex", "男"));
        bulkRequest.add(new IndexRequest().index("user").id("1004")
                .source(XContentType.JSON, "name", "wangwu", "age", 40, "sex", "女"));
        bulkRequest.add(new IndexRequest().index("user").id("1005")
                .source(XContentType.JSON, "name", "wangwu", "age", 50, "sex", "男"));
        bulkRequest.add(new IndexRequest().index("user").id("1006")
                .source(XContentType.JSON, "name", "wangwu", "age", 50, "sex", "男"));
        BulkResponse response = esClient.bulk(bulkRequest, RequestOptions.DEFAULT);
        System.out.println(response.getTook());
        System.out.println(response.getItems());
    }
​
    private void batchDel(RestHighLevelClient esClient) throws IOException {
        System.out.println("批量删除数据");
        BulkRequest bulkRequest = new BulkRequest();
        bulkRequest.add(new DeleteRequest().index("user").id("1001"));
        bulkRequest.add(new DeleteRequest().index("user").id("1002"));
        bulkRequest.add(new DeleteRequest().index("user").id("1003"));
        BulkResponse response = esClient.bulk(bulkRequest, RequestOptions.DEFAULT);
        System.out.println(response.getTook());
        System.out.println(response.getItems());
    }
​
    private void queryAll(RestHighLevelClient esClient) throws IOException {
        System.out.println("全量查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void querySelective(RestHighLevelClient esClient) throws IOException {
        System.out.println("条件查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().query(QueryBuilders.termQuery("age", 30));
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void queryPage(RestHighLevelClient esClient) throws IOException {
        System.out.println("分页查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
        searchSourceBuilder.from(0);
        searchSourceBuilder.size(2);
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void querySort(RestHighLevelClient esClient) throws IOException {
        System.out.println("排序查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
        searchSourceBuilder.sort("age", SortOrder.DESC);
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void queryFilter(RestHighLevelClient esClient) throws IOException {
        System.out.println("过滤查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder().query(QueryBuilders.matchAllQuery());
        String[] includes = {"name"};
        String[] excludes = {};
        searchSourceBuilder.fetchSource(includes, excludes);
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void zuheFilter(RestHighLevelClient esClient) throws IOException {
        System.out.println("组合查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        BoolQueryBuilder boolQueryBuilder = QueryBuilders.boolQuery();
        boolQueryBuilder.mustNot(QueryBuilders.matchQuery("sex", "男"));
        RangeQueryBuilder range = QueryBuilders.rangeQuery("age");
        range.gt(0);
        range.lt(100);
        FuzzyQueryBuilder fuzziness = QueryBuilders.fuzzyQuery("name", "wangwu").fuzziness(Fuzziness.ONE);
        TermQueryBuilder termQueryBuilder = QueryBuilders.termQuery("name", "zhangsan");
        HighlightBuilder highlightBuilder = new HighlightBuilder();
        highlightBuilder.preTags("");
        highlightBuilder.postTags("");
        // 多个 query 条件会以最后一个为准
        SearchSourceBuilder searchSourceBuilder =
                new SearchSourceBuilder().query(boolQueryBuilder).query(range).query(fuzziness).query(termQueryBuilder)
                        .highlighter(highlightBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void aggrFilter(RestHighLevelClient esClient) throws IOException {
        System.out.println("聚合查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        MaxAggregationBuilder aggregationBuilder = AggregationBuilders.max("maxAge").field("age");
        searchSourceBuilder.aggregation(aggregationBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    private void groupFilter(RestHighLevelClient esClient) throws IOException {
        System.out.println("分组查询数据");
        SearchRequest searchRequest = new SearchRequest();
        searchRequest.indices("user");
        SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
        AggregationBuilder aggregationBuilder = AggregationBuilders.terms("ageGroup").field("age");
        searchSourceBuilder.aggregation(aggregationBuilder);
        searchRequest.source(searchSourceBuilder);
        SearchResponse response = esClient.search(searchRequest, RequestOptions.DEFAULT);
        SearchHits hits = response.getHits();
        System.out.println(hits.getTotalHits());
        System.out.println(response.getTook());
        for (SearchHit searchHit : hits) {
            System.out.println(searchHit.getSourceAsString());
        }
    }
​
    public static void main(String[] args) throws IOException {
        RestHighLevelClient esClient = new RestHighLevelClient(
                RestClient.builder(new HttpHost("localhost", 9200, "http")));
​
        new Test().groupFilter(esClient);
​
        esClient.close();
    }
}