如果注解builder.setBolt，那么它运行正确。请告诉我哪里出错了

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());