scala - 无法访问类 TransportClient 中的构造函数 TransportClient

Question

我为 ElasticSearch 中的文档索引编写了以下类:

import java.net.InetAddress
import com.typesafe.config.ConfigFactory
import org.elasticsearch.client.transport.TransportClient
import org.elasticsearch.common.settings.Settings
import org.elasticsearch.common.transport.InetSocketTransportAddress
import play.api.libs.json.{JsString, JsValue}

/**
  * Created by liana on 12/07/16.
  */
class ElasticSearchConnector {

  private var transportClient: TransportClient = null
  private val host = "localhost"
  private val port = 9300
  private val cluster = "elasticsearch"
  private val indexName = "tests"
  private val docType = "test"

  def configElasticSearch(): Unit =
  {
    val settings = Settings.settingsBuilder().put("cluster.name", cluster).build()
    transportClient = new TransportClient(settings)
    transportClient.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(host), port.toInt))
  }

  def putText(json: String, id: Int): String =
  {
    val response = transportClient.prepareIndex(indexName, docType, id)
                                  .setSource(json)
                                  .get()
    val responseId = response.getId
    responseId
  }
}

然后我按如下方式使用它:

val json = """val jsonString =
{
"title": "Elastic",
"price": 2000,
"author":{
"first": "Zachary",
"last": "Tong";
}
}"""

val ec = new ElasticSearchConnector()
ec.configElasticSearch()
val id = ec.putText(json)
System.out.println(id)

这是我收到的错误消息:

Error:(28, 23) constructor TransportClient in class TransportClient cannot be accessed in class ElasticSearchConnector transportClient = new TransportClient(settings)

这里有什么问题？

Answer 1

在 Elasticsearch 连接器 API 中，TransportClient 类没有公共(public)构造函数，但有一个声明的私有(private)构造函数。因此，您不能直接“新建” TransportClient 的实例。 API 使用 Builder Pattern相当严重，因此为了创建 TransportClient 的实例，您需要执行以下操作:

val settings = Settings.settingsBuilder().put("cluster.name", cluster).build()
val transportClient = TransportClient.builder().settings(settings).build()
transportClient.addTransportAddress(new InetSocketTransportAddress(InetAddress.getByName(host), port.toInt))