需要有关通过Java使用反向代理URL设置Elastic Search的帮助。

在运行于公司专用网络的VM（localhost：9200）中安装了Elastic Search。我们为该网址启用了反向代理。在浏览器中粘贴URL时，工作正常。

https://demo-es.xyz.abc.com

{
  "name" : "13abc1","cluster_name" : "elasticsearch","cluster_uuid" : "5u9dqlSBRSmpabcdefghij","version" : {
    "number" : "7.8.0","build_flavor" : "default","build_type" : "deb","build_hash" : "12341234.......","build_date" : "2020-6-10T03:35:50.234439Z","build_snapshot" : false,"lucene_version" : "8.5.1","minimum_wire_compatibility_version" : "6.8.0","minimum_index_compatibility_version" : "6.0.0-beta1"
  },"tagline" : "You Know,for Search"
}

但是我需要通过Java代码进行连接。我正在使用以下代码进行连接，但接收到连接被拒绝。

public ElasticSearch(String host,int port,String protocol) throws IOException {
    client = new RestHighLevelClient(
            RestClient.builder(
                    new HttpHost("demo-es.xyz.abc.com",443)));
}

我也尝试使用它，但是没有用

RestClient.builder(new HttpHost("demo-es.xyz.abc.com",443,"https")));

错误：

org.apache.http.ConnectionClosedException: Connection is closed
    at org.elasticsearch.client.RestClient.extractAndWrapCause(RestClient.java:813)
[]
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:248)
    at org.elasticsearch.client.RestClient.performRequest(RestClient.java:235)
    at org.elasticsearch.client.RestHighLevelClient.internalPerformRequest(RestHighLevelClient.java:1611)
    at org.elasticsearch.client.RestHighLevelClient.performRequest(RestHighLevelClient.java:1581)
    at org.elasticsearch.client.RestHighLevelClient.performRequestAndParseEntity(RestHighLevelClient.java:1551)
    at org.elasticsearch.client.RestHighLevelClient.search(RestHighLevelClient.java:1067)
    at com.presto.banking.util.ElasticSearch.searchRecords(ElasticSearch.java:46)
    at com.presto.banking.util.ElasticSearch.main(ElasticSearch.java:76)
Caused by: org.apache.http.ConnectionClosedException: Connection is closed
    at org.apache.http.nio.protocol.HttpAsyncRequestExecutor.endOfInput(HttpAsyncRequestExecutor.java:356)
    at org.apache.http.impl.nio.DefaultNHttpClientConnection.consumeInput(DefaultNHttpClientConnection.java:261)
    at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:81)
    at org.apache.http.impl.nio.client.InternalIODispatch.onInputReady(InternalIODispatch.java:39)
    at org.apache.http.impl.nio.reactor.AbstractIODispatch.inputReady(AbstractIODispatch.java:114)
    at org.apache.http.impl.nio.reactor.BaseIOReactor.readable(BaseIOReactor.java:162)
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvent(AbstractIOReactor.java:337)
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.processEvents(AbstractIOReactor.java:315)
    at org.apache.http.impl.nio.reactor.AbstractIOReactor.execute(AbstractIOReactor.java:276)
    at org.apache.http.impl.nio.reactor.BaseIOReactor.execute(BaseIOReactor.java:104)
    at org.apache.http.impl.nio.reactor.AbstractMultiworkerIOReactor$Worker.run(AbstractMultiworkerIOReactor.java:591)
    at java.lang.Thread.run(Thread.java:748)

是否存在通过Java Source连接Elastic Search的替代方法？