Elasticsearch实战Java High Level REST Client实现员工管理案例

开发环境：

elasticsearch:7.0.0
kibana:7.0.0
JDK: 1.8.0_201
maven: 3.6.1

这里讲的是实战对于如何安装elasticsearch，配置java环境变量，配置maven不做讲解

详细请查看：
elasticsearch学习笔记（四）——在windows上安装和启动Elasticsearch
https://segmentfault.com/a/11...
增量同步mysql 数据到elasticsearch canal adapter方式(binlog)实现（从零到一超级详
https://segmentfault.com/a/11...
里面有做详细讲解，对于搭建ES集群目前还没有写相关文章，读者可以自行google

1、在springboot项目的pom文件中添加elasticsearch的依赖

        
            org.elasticsearch
            elasticsearch
            7.0.0
        

        
            org.elasticsearch.client
            elasticsearch-rest-high-level-client
            7.0.0

2、实现员工信息的增删改查

（1）构建client

我的ES机器IP是192.168.254.131，读者可自行更换

RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200, "http")
                )
        );
client.close();

对于多个ip的情况，直接使用如下格式即可：

RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("IP", PORT, "http"),
                        new HttpHost("IP", PORT, "http")
                        ...
                )
        );
client.close();

（2）创建员工信息

我个人比较喜欢这种格式的实现：
还有基于json字符串和map的，读者可查看：
https://www.elastic.co/guide/...
格式如下

        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field(name, value);
            builder.field(name, value);
            builder.field(name, value);
            builder.field(name, value);
            builder.field(name, value);
            ...
        }
        builder.endObject();
        IndexRequest request = new IndexRequest(index).id(id).source(builder);
        IndexResponse indexResponse =  client.index(request, RequestOptions.DEFAULT);

示例：

        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field("name", "jack");
            builder.field("age", 27);
            builder.field("position", "technique");
            builder.field("country", "china");
            builder.field("join_date", "2017-01-01");
            builder.field("salary", 10000);
        }
        builder.endObject();
        IndexRequest request = new IndexRequest("employee").id("1").source(builder);
        IndexResponse indexResponse =  client.index(request, RequestOptions.DEFAULT);

（3）根据ID获取员工信息

详细请查看：
https://www.elastic.co/guide/...
格式：

        GetRequest request = new GetRequest(index, id);
        GetResponse response = client.get(request, RequestOptions.DEFAULT);

示例：

        GetRequest request = new GetRequest("employee", "1");
        GetResponse response = client.get(request, RequestOptions.DEFAULT);

（4）修改员工信息

详细请查看：
https://www.elastic.co/guide/...
格式：

        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field(name, value);
        }
        builder.endObject();
        UpdateRequest request = new UpdateRequest(index, id).doc(builder);
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);

示例：

        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field("position", "technique");
        }
        builder.endObject();
        UpdateRequest request = new UpdateRequest("employee", "1").doc(builder);
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);

（5）删除员工信息

详细请查看：
https://www.elastic.co/guide/...
格式：

        DeleteRequest request = new DeleteRequest(index, id);
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);

示例：

        DeleteRequest request = new DeleteRequest("employee", "1");
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);

（6）测试员工信息的增删改查

完整测试代码：

    /**
     * 创建员工信息
     * @param client
     * @throws Exception
     */
    private static void createEmployee(RestHighLevelClient client) throws Exception {
        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field("name", "jack");
            builder.field("age", 27);
            builder.field("position", "technique");
            builder.field("country", "china");
            builder.field("join_date", "2017-01-01");
            builder.field("salary", 10000);
        }
        builder.endObject();
        IndexRequest request = new IndexRequest("employee").id("1").source(builder);
        IndexResponse indexResponse =  client.index(request, RequestOptions.DEFAULT);
        System.out.println(indexResponse.getResult());
    }

    /**
     * 获取员工信息
     * @param client
     */
    private static void getEmployee(RestHighLevelClient client) throws IOException {
        GetRequest request = new GetRequest("employee", "1");
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        System.out.println(response.getSourceAsString());
    }

    /**
     * 修改员工信息
     * @param client
     */
    private static void updateEmployee(RestHighLevelClient client) throws IOException {
        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field("position", "technique");
        }
        builder.endObject();
        UpdateRequest request = new UpdateRequest("employee", "1").doc(builder);
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
    }

    /**
     * 删除员工信息
     * @param client
     */
    private static void deleteEmployee(RestHighLevelClient client) throws IOException {
        DeleteRequest request = new DeleteRequest("employee", "1");
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
    }

1、测试新增

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200, "http")
                )
        );
        createEmployee(client);
        client.close();
    }

结果：

CREATED

2、测试获取数据

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200, "http")
                )
        );

        getEmployee(client);
        client.close();
    }

结果：

{"name":"jack","age":27,"position":"technique manager","country":"china","join_date":"2017-01-01","salary":10000}

3、测试更新数据

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200, "http")
                )
        );

        getEmployee(client);
        updateEmployee(client);
        getEmployee(client)
        client.close();
    }

结果：

{"name":"jack","age":27,"position":"technique manager","country":"china","join_date":"2017-01-01","salary":10000}
UPDATE
{"name":"jack","age":27,"position":"technique","country":"china","join_date":"2017-01-01","salary":10000}

4、测试删除数据

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200, "http")
                )

        );
        getEmployee(client);
        deleteEmployee(client);
        getEmployee(client);
        client.close();
    }

结果：

{"name":"jack","age":27,"position":"technique","country":"china","join_date":"2017-01-01","salary":10000}
DELETED
null

3、对员工信息进行复杂的搜索操作

需求：
（1）搜索职位中包含technique的员工
（2）同时要求age在30到40岁之间
（3）分页查询，查找第一页
准备数据：

    private static void prepareData(RestHighLevelClient client) throws IOException {
        client.index(new IndexRequest("employee").id("1").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "jack")
                .field("age", 27)
                .field("position", "technique software")
                .field("country", "china")
                .field("join_date", "2017-01-01")
                .field("salary", 10000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("2").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "marry")
                .field("age", 35)
                .field("position", "technique manager")
                .field("country", "china")
                .field("join_date", "2017-01-01")
                .field("salary", 12000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("3").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "tom")
                .field("age", 32)
                .field("position", "senior technique software")
                .field("country", "china")
                .field("join_date", "2016-01-01")
                .field("salary", 11000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("4").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "jen")
                .field("age", 25)
                .field("position", "junior finance")
                .field("country", "usa")
                .field("join_date", "2016-01-01")
                .field("salary", 7000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("5").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "mike")
                .field("age", 37)
                .field("position", "finance manager")
                .field("country", "usa")
                .field("join_date", "2015-01-01")
                .field("salary", 15000)
                .endObject()
        ), RequestOptions.DEFAULT);

    }

执行：

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200)
                )
        );
        prepareData(client);
        client.close();
    }

然后构建查询语句：

GET /employee/_search
{
  "query": {
    "bool": {
      "must": [
        {
          "match": {
            "position": "technique"
          }
        }
      ],
      "filter": {
        "range": {
          "age": {
            "gte": 30,
            "lte": 40
          }
        }
      }
    }
  },
  "from": 0,
  "size": 1
}
{
  "took" : 3,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 2,
      "relation" : "eq"
    },
    "max_score" : 0.5598161,
    "hits" : [
      {
        "_index" : "employee",
        "_type" : "_doc",
        "_id" : "2",
        "_score" : 0.5598161,
        "_source" : {
          "name" : "marry",
          "age" : 35,
          "position" : "technique manager",
          "country" : "china",
          "join_date" : "2017-01-01",
          "salary" : 12000
        }
      }
    ]
  }
}

代码：

    private static void executeSearch(RestHighLevelClient client) throws IOException {
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.matchQuery("position", "technique"));
        builder.postFilter(QueryBuilders.rangeQuery("age").from(30).to(40));
        builder.from(0);
        builder.size(1);
        SearchRequest request = new SearchRequest();
        request.indices("employee");
        request.source(builder);
        SearchResponse response =  client.search(request, RequestOptions.DEFAULT);
        SearchHit[] hits = response.getHits().getHits();
        for (SearchHit hit : hits) {
            System.out.println(hit.getSourceAsString());
        }
    }

执行：

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200)
                )
        );
        executeSearch(client);
        client.close();
    }

结果：

{"name":"marry","age":35,"position":"technique manager","country":"china","join_date":"2017-01-01","salary":12000}

4、对员工信息进行聚合分析

需求：
（1）首先按照country国家来进行分组
（2）然后在每个country分组内，再按照入职年限进行分组
（3）最后计算每个分组内的平均薪资

GET /employee/_search
{
  "size": 0, 
  "aggs": {
    "group_by_country": {
      "terms": {
        "field": "country.keyword"
      },
      "aggs": {
        "group_by_join_date": {
          "date_histogram": {
            "field": "join_date",
            "interval": "year"
          },
          "aggs": {
            "avg_salary": {
              "avg": {
                "field": "salary"
              }
            }
          }
        }
      }
    }
  }
}

{
  "took" : 46,
  "timed_out" : false,
  "_shards" : {
    "total" : 1,
    "successful" : 1,
    "skipped" : 0,
    "failed" : 0
  },
  "hits" : {
    "total" : {
      "value" : 5,
      "relation" : "eq"
    },
    "max_score" : null,
    "hits" : [ ]
  },
  "aggregations" : {
    "group_by_country" : {
      "doc_count_error_upper_bound" : 0,
      "sum_other_doc_count" : 0,
      "buckets" : [
        {
          "key" : "china",
          "doc_count" : 3,
          "group_by_join_date" : {
            "buckets" : [
              {
                "key_as_string" : "2016-01-01T00:00:00.000Z",
                "key" : 1451606400000,
                "doc_count" : 1,
                "avg_salary" : {
                  "value" : 11000.0
                }
              },
              {
                "key_as_string" : "2017-01-01T00:00:00.000Z",
                "key" : 1483228800000,
                "doc_count" : 2,
                "avg_salary" : {
                  "value" : 11000.0
                }
              }
            ]
          }
        },
        {
          "key" : "usa",
          "doc_count" : 2,
          "group_by_join_date" : {
            "buckets" : [
              {
                "key_as_string" : "2015-01-01T00:00:00.000Z",
                "key" : 1420070400000,
                "doc_count" : 1,
                "avg_salary" : {
                  "value" : 15000.0
                }
              },
              {
                "key_as_string" : "2016-01-01T00:00:00.000Z",
                "key" : 1451606400000,
                "doc_count" : 1,
                "avg_salary" : {
                  "value" : 7000.0
                }
              }
            ]
          }
        }
      ]
    }
  }
}

执行：

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("192.168.254.131", 9200)
                )
        );
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.aggregation(AggregationBuilders.terms("group_by_country").field("country.keyword")
                            .subAggregation(AggregationBuilders.dateHistogram("group_by_join_date").field("join_date")
                                            .dateHistogramInterval(DateHistogramInterval.YEAR)
                                            .subAggregation(AggregationBuilders.avg("avg_salary").field("salary"))));
        SearchRequest request = new SearchRequest();
        request.indices("employee");
        request.source(builder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        Map aggregationMap = response.getAggregations().asMap();
        ParsedStringTerms group_by_country = (ParsedStringTerms)  aggregationMap.get("group_by_country");
        for (Terms.Bucket groupByCountryBucket : group_by_country.getBuckets()) {
            System.out.println(groupByCountryBucket.getKey() + ":" + groupByCountryBucket.getDocCount());

            Histogram groupByJoinDate = (Histogram) groupByCountryBucket.getAggregations().asMap().get("group_by_join_date");
            for (Histogram.Bucket groupByJoinDateBucket : groupByJoinDate.getBuckets()) {
                System.out.println(groupByJoinDateBucket.getKey() + ":" + groupByJoinDateBucket.getDocCount());

                Avg avg = (Avg) groupByJoinDateBucket.getAggregations().asMap().get("avg_salary");
                System.out.println(avg.getValue());
            }
        }
        client.close();
    }

结果：

china:3
2016-01-01T00:00Z:1
11000.0
2017-01-01T00:00Z:2
11000.0
usa:2
2015-01-01T00:00Z:1
15000.0
2016-01-01T00:00Z:1
7000.0

附上完整代码：

EmployeeCRUDApp.java

import org.apache.http.HttpHost;
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.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.common.xcontent.XContentBuilder;
import org.elasticsearch.common.xcontent.XContentFactory;

import java.io.IOException;

public class EmployeeCRUDApp {

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("127.0.0.1", 9200, "http")
                )

        );

        createEmployee(client);
        getEmployee(client);
        updateEmployee(client);
        getEmployee(client);
        deleteEmployee(client);
        getEmployee(client);
        client.close();
    }

    /**
     * 创建员工信息
     * @param client
     * @throws Exception
     */
    private static void createEmployee(RestHighLevelClient client) throws Exception {
        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field("name", "jack");
            builder.field("age", 27);
            builder.field("position", "technique manager");
            builder.field("country", "china");
            builder.field("join_date", "2017-01-01");
            builder.field("salary", 10000);
        }
        builder.endObject();
        IndexRequest request = new IndexRequest("employee").id("1").source(builder);
        IndexResponse indexResponse =  client.index(request, RequestOptions.DEFAULT);
        System.out.println(indexResponse.getResult());
    }

    /**
     * 获取员工信息
     * @param client
     */
    private static void getEmployee(RestHighLevelClient client) throws IOException {
        GetRequest request = new GetRequest("employee", "1");
        GetResponse response = client.get(request, RequestOptions.DEFAULT);
        System.out.println(response.getSourceAsString());
    }

    /**
     * 修改员工信息
     * @param client
     */
    private static void updateEmployee(RestHighLevelClient client) throws IOException {
        XContentBuilder builder = XContentFactory.jsonBuilder();
        builder.startObject();
        {
            builder.field("position", "technique");
        }
        builder.endObject();
        UpdateRequest request = new UpdateRequest("employee", "1").doc(builder);
        UpdateResponse response = client.update(request, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
    }

    /**
     * 删除员工信息
     * @param client
     */
    private static void deleteEmployee(RestHighLevelClient client) throws IOException {
        DeleteRequest request = new DeleteRequest("employee", "1");
        DeleteResponse response = client.delete(request, RequestOptions.DEFAULT);
        System.out.println(response.getResult());
    }

}

EmployeeSearchApp.java

import org.apache.http.HttpHost;
import org.elasticsearch.action.index.IndexRequest;
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.common.xcontent.XContentFactory;
import org.elasticsearch.index.query.QueryBuilders;
import org.elasticsearch.search.SearchHit;
import org.elasticsearch.search.builder.SearchSourceBuilder;

import java.io.IOException;

/**
 * 员工搜索应用程序
 */
public class EmployeeSearchApp {

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("127.0.0.1", 9200)
                )
        );
        prepareData(client);
        executeSearch(client);
        client.close();
    }

    /**
     * 执行搜索操作
     * @param client
     */
    private static void executeSearch(RestHighLevelClient client) throws IOException {
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.query(QueryBuilders.matchQuery("position", "technique"));
        builder.postFilter(QueryBuilders.rangeQuery("age").from(30).to(40));
        builder.from(0);
        builder.size(1);
        SearchRequest request = new SearchRequest();
        request.indices("employee");
        request.source(builder);
        SearchResponse response =  client.search(request, RequestOptions.DEFAULT);
        SearchHit[] hits = response.getHits().getHits();
        for (SearchHit hit : hits) {
            System.out.println(hit.getSourceAsString());
        }
    }

    /**
     * 准备数据
     * @param client
     */
    private static void prepareData(RestHighLevelClient client) throws IOException {
        client.index(new IndexRequest("employee").id("1").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "jack")
                .field("age", 27)
                .field("position", "technique software")
                .field("country", "china")
                .field("join_date", "2017-01-01")
                .field("salary", 10000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("2").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "marry")
                .field("age", 35)
                .field("position", "technique manager")
                .field("country", "china")
                .field("join_date", "2017-01-01")
                .field("salary", 12000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("3").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "tom")
                .field("age", 32)
                .field("position", "senior technique software")
                .field("country", "china")
                .field("join_date", "2016-01-01")
                .field("salary", 11000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("4").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "jen")
                .field("age", 25)
                .field("position", "junior finance")
                .field("country", "usa")
                .field("join_date", "2016-01-01")
                .field("salary", 7000)
                .endObject()
        ), RequestOptions.DEFAULT);
        client.index(new IndexRequest("employee").id("5").source(XContentFactory.jsonBuilder()
                .startObject()
                .field("name", "mike")
                .field("age", 37)
                .field("position", "finance manager")
                .field("country", "usa")
                .field("join_date", "2015-01-01")
                .field("salary", 15000)
                .endObject()
        ), RequestOptions.DEFAULT);

    }

}

EmployeeAggrApp.java

public class EmployeeAggrApp {

    public static void main(String[] args) throws Exception {
        RestHighLevelClient client = new RestHighLevelClient(
                RestClient.builder(
                        new HttpHost("127.0.0.1", 9200)
                )
        );
        SearchSourceBuilder builder = new SearchSourceBuilder();
        builder.aggregation(AggregationBuilders.terms("group_by_country").field("country.keyword")
                            .subAggregation(AggregationBuilders.dateHistogram("group_by_join_date").field("join_date")
                                            .dateHistogramInterval(DateHistogramInterval.YEAR)
                                            .subAggregation(AggregationBuilders.avg("avg_salary").field("salary"))));
        SearchRequest request = new SearchRequest();
        request.indices("employee");
        request.source(builder);
        SearchResponse response = client.search(request, RequestOptions.DEFAULT);
        Map aggregationMap = response.getAggregations().asMap();
        ParsedStringTerms group_by_country = (ParsedStringTerms)  aggregationMap.get("group_by_country");
        for (Terms.Bucket groupByCountryBucket : group_by_country.getBuckets()) {
            System.out.println(groupByCountryBucket.getKey() + ":" + groupByCountryBucket.getDocCount());

            Histogram groupByJoinDate = (Histogram) groupByCountryBucket.getAggregations().asMap().get("group_by_join_date");
            for (Histogram.Bucket groupByJoinDateBucket : groupByJoinDate.getBuckets()) {
                System.out.println(groupByJoinDateBucket.getKey() + ":" + groupByJoinDateBucket.getDocCount());

                Avg avg = (Avg) groupByJoinDateBucket.getAggregations().asMap().get("avg_salary");
                System.out.println(avg.getValue());
            }
        }
        client.close();
    }
}

Elasticsearch实战Java High Level REST Client实现员工管理案例

开发环境：

这里讲的是实战对于如何安装elasticsearch，配置java环境变量，配置maven不做讲解

1、在springboot项目的pom文件中添加elasticsearch的依赖

2、实现员工信息的增删改查

（1）构建client

（2）创建员工信息

（3）根据ID获取员工信息

（4）修改员工信息

（5）删除员工信息

（6）测试员工信息的增删改查

3、对员工信息进行复杂的搜索操作

4、对员工信息进行聚合分析

附上完整代码：

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