启动topo抛出如下异常：
Exception in thread "main" java.lang.IllegalStateException: Spout 'DetrUpdateEvent' contains a non-serializable field of type com.gdl.trolley.stormclient.TrolleySpout$StormMessageListner, which was instantiated prior to topology creation. com.gdl.trolley.stormclient.TrolleySpout$StormMessageListner should be instantiated within the prepare method of 'DetrUpdateEvent at the earliest.
at backtype.storm.topology.TopologyBuilder.createTopology(TopologyBuilder.java:138)
at com.gdl.gdl.gdlpsr.processor.detrupdate.DetrupdateTopology.main(DetrupdateTopology.java:42)
Caused by: java.lang.RuntimeException: java.io.NotSerializableException: com.gdl.trolley.stormclient.TrolleySpout$StormMessageListner
at backtype.storm.utils.Utils.javaSerialize(Utils.java:196)
at backtype.storm.topology.TopologyBuilder.createTopology(TopologyBuilder.java:135)
... 1 more
Caused by: java.io.NotSerializableException: com.gdl.trolley.stormclient.TrolleySpout$StormMessageListner
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1184)
at java.io.ObjectOutputStream.defaultWriteFields(ObjectOutputStream.java:1548)
at java.io.ObjectOutputStream.writeSerialData(ObjectOutputStream.java:1509)
at java.io.ObjectOutputStream.writeOrdinaryObject(ObjectOutputStream.java:1432)
at java.io.ObjectOutputStream.writeObject0(ObjectOutputStream.java:1178)
at java.io.ObjectOutputStream.writeObject(ObjectOutputStream.java:348)
at backtype.storm.utils.Utils.javaSerialize(Utils.java:192)
... 2 more在storm和bolt和spout中不能包含非静态且在对象创建时初始化的字段。如下面代码时不被允许的。
public class TrolleySpout extends KafkaSpout {
private static KafkaSpoutConfig.Builder builder = KafkaSpoutConfig.builderStringBytes(UpdateConfig.getInstance().getBrokerHosts()
, UpdateConfig.getInstance().getAppid());
private StormMessageListner stormMessageListner = new StormMessageListner();解决方案：对于bolt，在pepare方法中完成初始化。对于spout，要么重构，要么冒险进行序列化。
实行序列化有什么危险呢？