java - Scala、Elasticsearch 新的 RestHighLevelClient 和 BulkProcessor

Question

在我的 Scala 项目中，我试图用新的 RestHighLevelClient 更改旧的 transportClient 以连接到 Elasticsearch (6.1)。

但我在尝试创建 BulkProcessor 时遇到问题，我不知道如何将此示例从 Java 转换为 Scala

`BulkProcessor.Builder builder = BulkProcessor.builder(client::bulkAsync, listener);`

我的代码是这样的:

val client=new RestHighLevelClient(
  RestClient.builder(
    new HttpHost("localhost", 9200, "http") ) )

val builder: BulkProcessor.Builder =BulkProcessor.builder(client, listener)

但是我得到这个错误:

 overloaded method value builder with alternatives:
[error]   (x$1: java.util.function.BiConsumer[org.elasticsearch.action.bulk.BulkRequest,org.elasticsearch.action.ActionListener[org.elasticsearch.action.bulk.BulkResponse]],x$2: org.elasticsearch.action.bulk.BulkProcessor.Listener)org.elasticsearch.action.bulk.BulkProcessor.Builder <and>
[error]   (x$1: org.elasticsearch.client.Client,x$2: org.elasticsearch.action.bulk.BulkProcessor.Listener)org.elasticsearch.action.bulk.BulkProcessor.Builder
[error]  cannot be applied to (org.elasticsearch.client.RestHighLevelClient, org.elasticsearch.action.bulk.BulkProcessor.Listener)
[error]   val builder: BulkProcessor.Builder =BulkProcessor.builder(client, listener)

如果我尝试将“client::bulkAsync”转换为“client.bulkAsync _”或“client::bulkAsync(_._._ )”获取其他错误:

type mismatch;
[error] found   : org.apache.http.Header*
[error] required: org.apache.http.Header
[error] var bulkProcessor =BulkProcessor.builder(client.bulkAsync(_,_,_),listener)

这是 Java 中的 bulkAsync 方法:

 public final void bulkAsync(BulkRequest bulkRequest, ActionListener<BulkResponse> listener, Header... headers) {

有人在 Scala 中使用过 RestHighLevelClient 和 BulkProcessor 吗？或者知道如何解决这个错误？

Answer 1

Scala 2.11 与 Java 8 函数接口(interface)没有良好的互操作性。创建 BiConsumerId(接受两个输入参数并且不返回任何结果)应该可以解决问题:

val bulkAsyncAsJava :  BiConsumer[BulkRequest, ActionListener[BulkResponse]] = new BiConsumer[BulkRequest, ActionListener[BulkResponse]] {
  override def accept(bulkRequest : BulkRequest , actionListener:ActionListener[BulkResponse]): Unit = {
    restHighLevelClient.bulkAsync(bulkRequest, actionListener)
  }
}
val bulkProcessor = BulkProcessor.builder(bulkAsyncAsJava, new BulkProcessor.Listener() {
override def beforeBulk(executionId: Long, request: BulkRequest): Unit = {
}

override

def afterBulk(executionId: Long, request: BulkRequest, response: BulkResponse): Unit = {
}

override

def afterBulk(executionId: Long, request: BulkRequest, failure: Throwable): Unit = {
}}).build