title: kafka spout can't connect to kafka topic
body: <p>I'm trying to connect a KafkaSpout belonging to a storm topology running on a <code>LocalCluster</code> object. I wrote this code according to the documentation I found on <a href="https://github.com/apache/storm/tree/master/external/storm-kafka" rel="nofollow">https://github.com/apache/storm/tree/master/external/storm-kafka</a>.</p>
  
  <pre><code> private static final String brokerZkStr = "localhost:2181";
  private static final String topic = "/test-topic-multi";
  
  public void startTopology()
  {
  
      BrokerHosts hosts = new ZkHosts(brokerZkStr);
      SpoutConfig conf = new SpoutConfig(hosts, topic, "localhost:2181", UUID
              .randomUUID().toString());
  
  
      KafkaSpout kafkaSput = new KafkaSpout(conf);
  
      TopologyBuilder builder = new TopologyBuilder();
  
      builder.setSpout("kafka-spout", kafkaSput);
  
      Config topConfig = new Config();
      topConfig.setDebug(true);
  
      LocalCluster cluster = new LocalCluster();
      cluster.submitTopology("HelloStorm", topConfig , builder.createTopology());
  }
  </code></pre>
  
  <p>I want to use a zookeeper instance running at <code>localhost:2181</code> but when a try to run the code I get the following error:</p>
  
  <pre><code>  java.lang.RuntimeException: java.lang.RuntimeException: java.lang.IllegalArgumentException: Invalid path string "/brokers/topics//test-topic-multi/partitions" caused by empty node name specified @16
  at storm.kafka.DynamicBrokersReader.getBrokerInfo(DynamicBrokersReader.java:81)
  at storm.kafka.trident.ZkBrokerReader.&lt;init&gt;(ZkBrokerReader.java:42)
  at storm.kafka.KafkaUtils.makeBrokerReader(KafkaUtils.java:57)
  at storm.kafka.KafkaSpout.open(KafkaSpout.java:87)
  </code></pre>
  
  <p>It seems to be just a problem of wrong settings but I can't solve it</p>
  
  <p>PS Kafka configuration is the following: 1 instance of Zookeeper and 2 brokers running on <code>localhost:9092</code> and <code>localhost:9093</code></p>