我想和flink和kafka一起进行集成测试。这个过程是从Kafka中读取数据，用flink进行一些操作，然后把数据流放到Kafka中。
我想从头到尾测试这个过程。现在我使用scalatest嵌入式Kafka。
我举了一个例子，我尽量简单：

import java.util.Properties

import net.manub.embeddedkafka.{EmbeddedKafka, EmbeddedKafkaConfig}
import org.apache.flink.api.common.serialization.SimpleStringSchema
import org.apache.flink.api.common.typeinfo.TypeInformation
import org.apache.flink.streaming.api.functions.sink.SinkFunction
import org.apache.flink.streaming.api.scala.StreamExecutionEnvironment
import org.apache.flink.streaming.connectors.kafka.{FlinkKafkaConsumer011, FlinkKafkaProducer011}
import org.scalatest.{Matchers, WordSpec}

import scala.collection.mutable.ListBuffer

object SimpleFlinkKafkaTest {

  class CollectSink extends SinkFunction[String] {
    override def invoke(string: String): Unit = {
      synchronized {
        CollectSink.values += string
      }
    }
  }

  object CollectSink {
    val values: ListBuffer[String] = ListBuffer.empty[String]
  }

  val kafkaPort = 9092
  val zooKeeperPort = 2181

  val props = new Properties()
  props.put("bootstrap.servers", "localhost:" + kafkaPort.toString)
  props.put("schema.registry.url", "localhost:" + zooKeeperPort.toString)

  val inputString = "mystring"
  val expectedString = "MYSTRING"
}

class SimpleFlinkKafkaTest extends WordSpec with Matchers with EmbeddedKafka {

  "runs with embedded kafka" should {

    "work" in {

      implicit val config = EmbeddedKafkaConfig(
        kafkaPort = SimpleFlinkKafkaTest.kafkaPort,
        zooKeeperPort = SimpleFlinkKafkaTest.zooKeeperPort
      )

      withRunningKafka {

        publishStringMessageToKafka("input-topic", SimpleFlinkKafkaTest.inputString)

        val env = StreamExecutionEnvironment.getExecutionEnvironment

        env.setParallelism(1)

        val kafkaConsumer = new FlinkKafkaConsumer011(
          "input-topic",
          new SimpleStringSchema,
          SimpleFlinkKafkaTest.props
        )

        implicit val typeInfo = TypeInformation.of(classOf[String])

        val inputStream = env.addSource(kafkaConsumer)

        val outputStream = inputStream.map(_.toUpperCase)

        val kafkaProducer = new FlinkKafkaProducer011(
          "output-topic",
          new SimpleStringSchema(),
          SimpleFlinkKafkaTest.props
        )
        outputStream.addSink(kafkaProducer)
        env.execute()
        consumeFirstStringMessageFrom("output-topic") shouldEqual SimpleFlinkKafkaTest.expectedString

      }
    }
  }
}

我有个错误，所以我加了一行 implicit val typeInfo = TypeInformation.of(classOf[String]) 但我真的不明白我为什么要这么做。
现在这个代码不起作用，它运行时没有中断，但不停止，也不给出任何结果。
有人知道吗？更好的办法是测试这种管道。
谢谢！
编辑：添加 env.execute() 改变错误。