获取 backtype.storm.generated.InvalidTopologyException: null 。如果我评论对 setBolt 的调用，它就会运行

Question

如果评论 builder.setBolt 然后它运行 correctly.Please 告诉我错在哪里

    TopologyBuilder builder = new TopologyBuilder();
    builder.setSpout("words", new TestWordSpout(), 3);
    //Calling setBolt
    builder.setBolt("exc", new ExclaimBolt(),3)
    .allGrouping("words");

    Config conf = new Config();
    conf.setDebug(false);
    //conf.setNumWorkers(2);

    LocalCluster cluster = new LocalCluster();
    cluster.submitTopology("test", conf, builder.createTopology());

Answer 1

尚未在 Spout 中声明输出字段。声明后它工作正常。

代码示例(in u bolt class):

@Override

public void declareOutputFields(OutputFieldsDeclarer declarer) {

    declarer.declare(new Fields("msg"));//based on u project

}

获取 backtype.storm.generated.InvalidTopologyException: null 。如果我评论对 setBolt 的调用，它就会运行

Getting backtype.storm.generated.InvalidTopologyException: null .If I comment call to setBolt it runs

apache-storm