使用elasticsearch-rest-high-level-client 7.1.1版本遇到的问题，
在GitHub上发了个issues

这个在官方文档没有说清楚，
pom中加入依赖

<dependency>
   <groupId>org.elasticsearch.client</groupId>
   <artifactId>elasticsearch-rest-high-level-client</artifactId>
   <version>7.1.1</version>
</dependency>

还需要加

    <!-- https://mvnrepository.com/artifact/org.elasticsearch/elasticsearch -->
        <dependency>
            <groupId>org.elasticsearch</groupId>
            <artifactId>elasticsearch</artifactId>
            <version>7.1.1</version>
        </dependency>