我是Drools的新手，我在eclipse上使用Drools 6.3 final和java 1.8。我没有使用ant / Maven来构建我的项目。同样的项目曾经适用于java 1.6和Drools 5.1。
现在，当我尝试运行该项目时，出现错误：
java.lang.Exception: java.lang.ClassCastException: org.drools.core.base.accumulators.BigDecimalAverageAccumulateFunction cannot be cast to org.drools.runtime.rule.AccumulateFunction
com.ibm.msg.client.jms.DetailedJMSException: JMSCC0037: A runtime exception was thrown by the MessageListener.onMessage() method. A message consumer with a registered message listener received an exception from the onMessage() method. The onMessage() method should be changed to avoid throwing exceptions.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:408)
at com.ibm.msg.client.commonservices.j2se.NLSServices.createException(NLSServices.java:313)
at com.ibm.msg.client.commonservices.nls.NLSServices.createException(NLSServices.java:388)
at com.ibm.msg.client.jms.internal.JmsErrorUtils.createException(JmsErrorUtils.java:104)
at com.ibm.msg.client.jms.internal.JmsMessageConsumerImpl$JmsProviderMessageListener.handleOnMessageThrowable(JmsMessageConsumerImpl.java:1178)
at com.ibm.msg.client.jms.internal.JmsMessageConsumerImpl$JmsProviderMessageListener.onMessage(JmsMessageConsumerImpl.java:1050)
at com.ibm.msg.client.wmq.internal.WMQAsyncConsumerShadow.honourNoLocal(WMQAsyncConsumerShadow.java:566)
at com.ibm.msg.client.wmq.internal.WMQAsyncConsumerShadow.consumer(WMQAsyncConsumerShadow.java:400)
at com.ibm.mq.jmqi.remote.internal.RemoteAsyncConsume.driveConsumer(RemoteAsyncConsume.java:1527)
at com.ibm.mq.jmqi.remote.internal.RemoteDispatchThread.run(RemoteDispatchThread.java:395)
at com.ibm.msg.client.commonservices.workqueue.WorkQueueItem.runTask(WorkQueueItem.java:209)
at com.ibm.msg.client.commonservices.workqueue.SimpleWorkQueueItem.runItem(SimpleWorkQueueItem.java:100)
at com.ibm.msg.client.commonservices.workqueue.WorkQueueItem.run(WorkQueueItem.java:224)
at com.ibm.msg.client.commonservices.workqueue.WorkQueueManager.runWorkQueueItem(WorkQueueManager.java:298)
at com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManagerImplementation$ThreadPoolWorker.run(WorkQueueManagerImplementation.java:1220)
Caused by: java.lang.Exception: java.lang.ClassCastException: org.drools.core.base.accumulators.BigDecimalAverageAccumulateFunction cannot be cast to org.drools.runtime.rule.AccumulateFunction
at com.ibm.msg.client.jms.internal.JmsMessageConsumerImpl$JmsProviderMessageListener.handleOnMessageThrowable(JmsMessageConsumerImpl.java:1180)
... 10 more
我也尝试了here提到的解决方案。
同样早些时候，我收到的错误有时会发生或有时会发生：
java.lang.Exception: java.lang.NoClassDefFoundError: org/drools/builder/CompositeKnowledgeBuilder
com.ibm.msg.client.jms.DetailedJMSException: JMSCC0037: A runtime exception was thrown by the MessageListener.onMessage() method. A message consumer with a registered message listener received an exception from the onMessage() method. The onMessage() method should be changed to avoid throwing exceptions.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:422)
at com.ibm.msg.client.commonservices.j2se.NLSServices.createException(NLSServices.java:313)
at com.ibm.msg.client.commonservices.nls.NLSServices.createException(NLSServices.java:388)
at com.ibm.msg.client.jms.internal.JmsErrorUtils.createException(JmsErrorUtils.java:104)
at com.ibm.msg.client.jms.internal.JmsMessageConsumerImpl$JmsProviderMessageListener.handleOnMessageThrowable(JmsMessageConsumerImpl.java:1178)
at com.ibm.msg.client.jms.internal.JmsMessageConsumerImpl$JmsProviderMessageListener.onMessage(JmsMessageConsumerImpl.java:1050)
at com.ibm.msg.client.wmq.internal.WMQAsyncConsumerShadow.honourNoLocal(WMQAsyncConsumerShadow.java:566)
at com.ibm.msg.client.wmq.internal.WMQAsyncConsumerShadow.consumer(WMQAsyncConsumerShadow.java:400)
at com.ibm.mq.jmqi.remote.internal.RemoteAsyncConsume.driveConsumer(RemoteAsyncConsume.java:1527)
at com.ibm.mq.jmqi.remote.internal.RemoteDispatchThread.run(RemoteDispatchThread.java:395)
at com.ibm.msg.client.commonservices.workqueue.WorkQueueItem.runTask(WorkQueueItem.java:209)
at com.ibm.msg.client.commonservices.workqueue.SimpleWorkQueueItem.runItem(SimpleWorkQueueItem.java:100)
at com.ibm.msg.client.commonservices.workqueue.WorkQueueItem.run(WorkQueueItem.java:224)
at com.ibm.msg.client.commonservices.workqueue.WorkQueueManager.runWorkQueueItem(WorkQueueManager.java:298)
at com.ibm.msg.client.commonservices.j2se.workqueue.WorkQueueManagerImplementation$ThreadPoolWorker.run(WorkQueueManagerImplementation.java:1220)
Caused by: java.lang.Exception: java.lang.NoClassDefFoundError: org/drools/builder/CompositeKnowledgeBuilder
at com.ibm.msg.client.jms.internal.JmsMessageConsumerImpl$JmsProviderMessageListener.handleOnMessageThrowable(JmsMessageConsumerImpl.java:1180)
... 10 more
Caused by: java.lang.NoClassDefFoundError: org/drools/builder/CompositeKnowledgeBuilder
任何人都可以指导我为什么会出现这些错误以及可能的解决方案是什么？
PS：我在构建路径中包含的Drools jar：
drools-compiler-6.3.0.Final.jar
drools-core-6.3.0.Final.jar
kie-api-6.3.0.Final.jar
kie-internal-6.3.0.Final.jar
knowledge-api-6.3.0.Final-sources.jar
org.apache.servicemix.bundles.drools-5.6.0.Final_1.jar -- this is the latest which i could find