SpringBoot整合ElasticSearch

1、导入依赖

这里的版本要和所按照的ELK版本匹配。

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<dependency>
    <groupId>org.elasticsearch.client</groupId>
    <artifactId>elasticsearch-rest-high-level-client</artifactId>
    <version>7.6.2</version>
</dependency>

在spring-boot-dependencies中所依赖的ELK版本位6.8.7

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<elasticsearch.version>6.8.7</elasticsearch.version>

image-20200511074437763

如果你使用Maven进行一个直接或间接继承spring-boot-dependencies（比如spring-boot-starter-parent）的构建，并想覆盖一个特定的第三方依赖，那你可以添加合适的元素。浏览spring-boot-dependencies POM可以获取一个全面的属性列表。例如，想要选择一个不同的elasticsearch版本，你可以添加以下内容将它改为7.6.2：

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<properties>
    ...
    <elasticsearch.version>7.6.2</elasticsearch.version>
</properties>

但是这只在你的Maven项目继承（直接或间接）自spring-boot-dependencies才有用。

如果你使用<scope>import</scope>，将spring-boot-dependencies添加到自己的dependencyManagement片段，那你必须自己重新定义artifact而不是覆盖属性。

image.png

需要在 <dependencyManagement> 下重新定义 artifact

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<dependency>
  <groupId>org.elasticsearch.client</groupId>
  <artifactId>elasticsearch-rest-high-level-client</artifactId>
  <version>${elasticsearch.version}</version>
</dependency>
<dependency>
  <groupId>org.elasticsearch</groupId>
  <artifactId>elasticsearch</artifactId>
  <version>${elasticsearch.version}</version>
</dependency>
<dependency>
  <groupId>org.elasticsearch.client</groupId>
  <artifactId>elasticsearch-rest-client</artifactId>
  <version>${elasticsearch.version}</version>
</dependency>

2、编写测试类

官方文档

1）测试保存数据

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@Test
public void indexData() throws IOException {
    IndexRequest indexRequest = new IndexRequest ("users");

    User user = new User();
    user.setUserName("张三");
    user.setAge(20);
    user.setGender("男");
    String jsonString = JSON.toJSONString(user);
    //设置要保存的内容
    indexRequest.source(jsonString, XContentType.JSON);
    //执行创建索引和保存数据
    IndexResponse index = client.index(indexRequest, GulimallElasticSearchConfig.COMMON_OPTIONS);

    System.out.println(index);

}

测试前：

image-20200511111618183

测试后：

image-20200511112025327

2）测试获取数据

https://raw.githubusercontent.com/elastic/elasticsearch/master/docs/src/test/resources/accounts.json（官方数据样本）

查询state=”AK”的文档：

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GET /bank/_search
{
  "query": {
    "match": {
      "state.keyword": "AK"
    }
  }
}

java 实现

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@Test
void searchState() throws IOException {
  // 创建检索条件
  SearchRequest searchRequest = new SearchRequest();
  //制定索引
  searchRequest.indices("bank");
  //指定DSL
  SearchSourceBuilder searchSourceBuilder = new SearchSourceBuilder();
  //构造检索条件
  searchSourceBuilder.query(QueryBuilders.matchQuery("state.keyword", "AK"));

  searchRequest.source(searchSourceBuilder);

  SearchResponse search = client.search(searchRequest, RequestOptions.DEFAULT);
  System.out.println(search.toString());

}

搜索address中包含mill的所有人的年龄分布以及平均年龄，平均薪资

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GET bank/_search
{
  "query": {
    "match": {
      "address": "Mill"
    }
  },
  "aggs": {
    "ageAgg": {
      "terms": {
        "field": "age",
        "size": 10
      }
    },
    "ageAvg": {
      "avg": {
        "field": "age"
      }
    },
    "balanceAvg": {
      "avg": {
        "field": "balance"
      }
    }
  }
}

java实现

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/**
 * 复杂检索:在bank中搜索address中包含mill的所有人的年龄分布以及平均年龄，平均薪资
 * @throws IOException
 */
@Test
public void searchData() throws IOException {
    //1. 创建检索请求
    SearchRequest searchRequest = new SearchRequest();

    //1.1）指定索引
    searchRequest.indices("bank");
    //1.2）构造检索条件
    SearchSourceBuilder sourceBuilder = new SearchSourceBuilder();
    sourceBuilder.query(QueryBuilders.matchQuery("address","Mill"));

    //1.2.1)按照年龄分布进行聚合
    TermsAggregationBuilder ageAgg=AggregationBuilders.terms("ageAgg").field("age").size(10);
    sourceBuilder.aggregation(ageAgg);

    //1.2.2)计算平均年龄
    AvgAggregationBuilder ageAvg = AggregationBuilders.avg("ageAvg").field("age");
    sourceBuilder.aggregation(ageAvg);
    //1.2.3)计算平均薪资
    AvgAggregationBuilder balanceAvg = AggregationBuilders.avg("balanceAvg").field("balance");
    sourceBuilder.aggregation(balanceAvg);

    System.out.println("检索条件："+sourceBuilder);
    searchRequest.source(sourceBuilder);
    //2. 执行检索
    SearchResponse searchResponse = client.search(searchRequest, RequestOptions.DEFAULT);
    System.out.println("检索结果："+searchResponse);

    //3. 将检索结果封装为Bean
    SearchHits hits = searchResponse.getHits();
    SearchHit[] searchHits = hits.getHits();
    for (SearchHit searchHit : searchHits) {
        String sourceAsString = searchHit.getSourceAsString();
        Account account = JSON.parseObject(sourceAsString, Account.class);
        System.out.println(account);

    }

    //4. 获取聚合信息
    Aggregations aggregations = searchResponse.getAggregations();

    Terms ageAgg1 = aggregations.get("ageAgg");

    for (Terms.Bucket bucket : ageAgg1.getBuckets()) {
        String keyAsString = bucket.getKeyAsString();
        System.out.println("年龄："+keyAsString+" ==> "+bucket.getDocCount());
    }
    Avg ageAvg1 = aggregations.get("ageAvg");
    System.out.println("平均年龄："+ageAvg1.getValue());

    Avg balanceAvg1 = aggregations.get("balanceAvg");
    System.out.println("平均薪资："+balanceAvg1.getValue());


}

可以尝试对比打印的条件和执行结果，和前面的ElasticSearch的检索语句和检索结果进行比较；