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。

<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

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

需要在项目中将它改为7.6.2

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

2、编写配置类

@Configuration
public class MyElasticConfig {

    public static final RequestOptions *COMMON_OPTIONS*;
    static{
        RequestOptions.Builder builder = RequestOptions.*DEFAULT*.toBuilder();
        *COMMON_OPTIONS* = builder.build();
    }

    @Bean
    public RestHighLevelClient esRestClient(){
        RestHighLevelClient restHighLevelClient = new RestHighLevelClient(
                RestClient.*builder*(
                        new HttpHost("192.168.30.100",9200,"http") //虚拟机ip地址及ElasticSearch端口号
    					
                )
        );
        return restHighLevelClient;
    }
}

3、编写测试类

1）测试保存数据

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-document-index.html

@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, MyElasticConfig.COMMON_OPTIONS);

    System.out.println(index);

}

测试前：

测试后：

2）测试获取数据

https://www.elastic.co/guide/en/elasticsearch/client/java-rest/current/java-rest-high-search.html

@Test
public void searchData() throws IOException {
    GetRequest getRequest = new GetRequest(
            "users",
            "_-2vAHIB0nzmLJLkxKWk");

    GetResponse getResponse = client.get(getRequest, RequestOptions.DEFAULT);
    System.out.println(getResponse);
    String index = getResponse.getIndex();
    System.out.println(index);
    String id = getResponse.getId();
    System.out.println(id);
    if (getResponse.isExists()) {
        long version = getResponse.getVersion();
        System.out.println(version);
        String sourceAsString = getResponse.getSourceAsString();
        System.out.println(sourceAsString);
        Map<String, Object> sourceAsMap = getResponse.getSourceAsMap();
        System.out.println(sourceAsMap);
        byte[] sourceAsBytes = getResponse.getSourceAsBytes();
    } else {

    }
}

查询state=”AK”的文档：

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

{
	"took": 1,
	"timed_out": false,
	"_shards": {
		"total": 1,
		"successful": 1,
		"skipped": 0,
		"failed": 0
	},
	"hits": {
		"total": {
			"value": 22,   //匹配到了22条
			"relation": "eq"
		},
		"max_score": 3.7952394,
		"hits": [{
			"_index": "bank",
			"_type": "account",
			"_id": "210",
			"_score": 3.7952394,
			"_source": {
				"account_number": 210,
				"balance": 33946,
				"firstname": "Cherry",
				"lastname": "Carey",
				"age": 24,
				"gender": "M",
				"address": "539 Tiffany Place",
				"employer": "Martgo",
				"email": "cherrycarey@martgo.com",
				"city": "Fairacres",
				"state": "AK"
			}
		},
           ....//省略其他
          ]
	}
}

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

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

/**
 * 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());


}