title: dependency in pom.xml is not working in flink kafka connector example
body: <p>src code:</p>
  
  <pre><code>/*
   * Licensed to the Apache Software Foundation (ASF) under one
   * or more contributor license agreements.  See the NOTICE file
   * distributed with this work for additional information
   * regarding copyright ownership.  The ASF licenses this file
   * to you under the Apache License, Version 2.0 (the
   * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   *     http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing, software
   * distributed under the License is distributed on an "AS IS" BASIS,
   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   * See the License for the specific language governing permissions and
   * limitations under the License.
   */
  
  
  import org.apache.flink.api.common.functions.MapFunction;
  import org.apache.flink.api.java.utils.ParameterTool;
  import org.apache.flink.streaming.api.datastream.DataStream;
  import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
  import org.apache.flink.streaming.connectors.kafka.FlinkKafkaConsumer082;
  import org.apache.flink.streaming.util.serialization.SimpleStringSchema;
  
  /**
   * Simple example on how to read with a Kafka consumer
   *
   * Note that the Kafka source is expecting the following parameters to be set
   *  - "bootstrap.servers" (comma separated list of kafka brokers)
   *  - "zookeeper.connect" (comma separated list of zookeeper servers)
   *  - "group.id" the id of the consumer group
   *  - "topic" the name of the topic to read data from.
   *
   * You can pass these required parameters using "--bootstrap.servers host:port,host1:port1 --zookeeper.connect host:port --topic testTopic"
   *
   * This is a valid input example:
   *      --topic test --bootstrap.servers localhost:9092 --zookeeper.connect localhost:2181 --group.id myGroup
   *
   *
   */
  public class ReadFromKafka {
  
      public static void main(String[] args) throws Exception {
          // create execution environment
          StreamExecutionEnvironment env = StreamExecutionEnvironment.getExecutionEnvironment();
  
          // parse user parameters
          ParameterTool parameterTool = ParameterTool.fromArgs(args);
  
          DataStream&lt;String&gt; messageStream = env.addSource(new FlinkKafkaConsumer082&lt;&gt;(parameterTool.getRequired("topic"), new SimpleStringSchema(), parameterTool.getProperties()));
  
          // print() will write the contents of the stream to the TaskManager's standard out stream
          // the rebelance call is causing a repartitioning of the data so that all machines
          // see the messages (for example in cases when "num kafka partitions" &lt; "num flink operators"
          messageStream.rebalance().map(new MapFunction&lt;String, String&gt;() {
              private static final long serialVersionUID = -6867736771747690202L;
  
              @Override
              public String map(String value) throws Exception {
                  return "Kafka and Flink says: " + value;
              }
          }).print();
  
          env.execute();
      }
  }
  </code></pre>
  
  <p>pom.xml:</p>
  
  <pre><code>&lt;project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd"&gt;
    &lt;modelVersion&gt;4.0.0&lt;/modelVersion&gt;
    &lt;groupId&gt;com.dataartisans&lt;/groupId&gt;
    &lt;artifactId&gt;kafka-example&lt;/artifactId&gt;
    &lt;version&gt;0.0.1-SNAPSHOT&lt;/version&gt;
    &lt;name&gt;kafkaex&lt;/name&gt;
    &lt;description&gt;this is flink kafka example&lt;/description&gt;
    &lt;dependencies&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.apache.flink&lt;/groupId&gt;
          &lt;artifactId&gt;flink-java&lt;/artifactId&gt;
          &lt;version&gt;1.9.1&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.apache.flink&lt;/groupId&gt;
          &lt;artifactId&gt;flink-streaming-java_2.12&lt;/artifactId&gt;
          &lt;version&gt;1.9.1&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.apache.flink&lt;/groupId&gt;
          &lt;artifactId&gt;flink-clients_2.12&lt;/artifactId&gt;
          &lt;version&gt;1.9.1&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;org.apache.flink&lt;/groupId&gt;
          &lt;artifactId&gt;flink-connector-kafka-0.9_2.12&lt;/artifactId&gt;
          &lt;version&gt;1.9.1&lt;/version&gt;
      &lt;/dependency&gt;
      &lt;dependency&gt;
          &lt;groupId&gt;com.googlecode.json-simple&lt;/groupId&gt;
          &lt;artifactId&gt;json-simple&lt;/artifactId&gt;
          &lt;version&gt;1.1&lt;/version&gt;
      &lt;/dependency&gt;  
  &lt;/dependencies&gt;
  &lt;/project&gt;
  </code></pre>
  
  <p>versions :</p>
  
  <pre><code>kafka : kafka_2.12-2.4.0
  flink : Apache Flink 1.9.1 for Scala 2.12
  OpenJDK version: 1.8
  </code></pre>