我的目标是找出在更新我的 MySQL 数据库期间更改了哪些列。
我的第一个想法是使用 Hibernate 事件系统。我已经实现了一个 PreUpdateEventListener。该事件允许访问更改的对象，我正在从数据库中检索旧对象。我正在使用 Java Object Diff Library 来比较两个对象。因为我只需要比较第一层，所以我配置了 Comparator 如下：
public static List<String> compareTillFirstLayer(Object pre, Object post) {
ArrayList<String> changedProperties = new ArrayList<String>();
InclusionResolver inclusionResolver = new InclusionResolver() {
@Override
public Inclusion getInclusion(DiffNode node) {
if (node.getParentNode().isRootNode()) {
return Inclusion.INCLUDED;
}
return null;
}
@Override
public boolean enablesStrictIncludeMode() {
return true;
}
};
ObjectDiffer objectDiffer = ObjectDifferBuilder.startBuilding().inclusion().resolveUsing(inclusionResolver)
.and().build();
DiffNode root = objectDiffer.compare(pre, post);
root.visitChildren(new DiffNode.Visitor() {
@Override
public void node(DiffNode node, Visit visit) {
changedProperties.add(node.getPropertyName());
}
});
return changedProperties;
}
这将返回对象的更改属性。为了找到与数据库列的连接，我使用了 Hibernate 配置，它的映射如下：
for (String property : changedProperties) {
PersistentClass persistentClass = HibernateUtil.getHibernateUtil().getConfiguration()
.getClassMapping(Consumer.class.getName());
String columnName = ((Column) persistentClass.getProperty(property).getColumnIterator().next())
.getName();
System.out.println(columnName);
}
这对我的 Consumer 对象很有效，但对于其他对象（如 Appointment 或 Vehicle 对象）却失败了。
即使是例外情况也因对象而异。
如果我尝试监视 Appointment 的更改，我会收到以下异常：
java.util.NoSuchElementException
at java.util.ArrayList$Itr.next(ArrayList.java:854)
at de.applicodata.serviceportal.persistence.hibernateEventListeners.PreUpdateEventImpl.onPreUpdate(PreUpdateEventImpl.java:88)
at org.hibernate.action.EntityUpdateAction.preUpdate(EntityUpdateAction.java:237)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:86)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)
at de.applicodata.serviceportal.persistence.dao.GeneralDAO.commit(GeneralDAO.java:189)
at de.applicodata.serviceportal.persistence.dao.GeneralDAO.update(GeneralDAO.java:556)
at de.applicodata.serviceportal.logic.entities.Appointment.updatePersistenceObject(Appointment.java:167)
at de.applicodata.serviceportal.faces.beans.MyAppointmentsBean.updateAppointmemt(MyAppointmentsBean.java:777)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.el.parser.AstValue.invoke(AstValue.java:279)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:273)
at org.jboss.weld.module.web.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
at org.jboss.weld.module.web.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at net.bull.javamelody.JsfActionListener.processAction(JsfActionListener.java:67)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:89)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:239)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:215)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at de.applicodata.serviceportal.faces.listener.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:36)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at de.applicodata.serviceportal.faces.listener.SessionTimeoutFilter.doFilter(SessionTimeoutFilter.java:129)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:199)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1136)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
在监视 Vehicle 对象的更改时，我收到以下异常，尽管这些对象与另一个不同：
java.lang.IllegalStateException: Couldn't find a differ for type: [B
at de.danielbechler.diff.differ.DifferProvider.retrieveDifferForType(DifferProvider.java:55)
at de.danielbechler.diff.differ.DifferDispatcher.compare(DifferDispatcher.java:196)
at de.danielbechler.diff.differ.DifferDispatcher.compareWithCircularReferenceTracking(DifferDispatcher.java:172)
at de.danielbechler.diff.differ.DifferDispatcher.compare(DifferDispatcher.java:159)
at de.danielbechler.diff.differ.DifferDispatcher.dispatch(DifferDispatcher.java:105)
at de.danielbechler.diff.differ.BeanDiffer.compareUsingIntrospection(BeanDiffer.java:114)
at de.danielbechler.diff.differ.BeanDiffer.compareUsingAppropriateMethod(BeanDiffer.java:104)
at de.danielbechler.diff.differ.BeanDiffer.compare(BeanDiffer.java:90)
at de.danielbechler.diff.differ.DifferDispatcher.compare(DifferDispatcher.java:202)
at de.danielbechler.diff.differ.DifferDispatcher.compareWithCircularReferenceTracking(DifferDispatcher.java:172)
at de.danielbechler.diff.differ.DifferDispatcher.compare(DifferDispatcher.java:159)
at de.danielbechler.diff.differ.DifferDispatcher.dispatch(DifferDispatcher.java:105)
at de.danielbechler.diff.ObjectDiffer.compare(ObjectDiffer.java:52)
at de.applicodata.serviceportal.persistence.hibernateEventListeners.HibernateEventObjectComparator.compareTillFirstLayer(HibernateEventObjectComparator.java:34)
at de.applicodata.serviceportal.persistence.hibernateEventListeners.PreUpdateEventImpl.onPreUpdate(PreUpdateEventImpl.java:63)
at org.hibernate.action.EntityUpdateAction.preUpdate(EntityUpdateAction.java:237)
at org.hibernate.action.EntityUpdateAction.execute(EntityUpdateAction.java:86)
at org.hibernate.engine.ActionQueue.execute(ActionQueue.java:273)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:265)
at org.hibernate.engine.ActionQueue.executeActions(ActionQueue.java:185)
at org.hibernate.event.def.AbstractFlushingEventListener.performExecutions(AbstractFlushingEventListener.java:321)
at org.hibernate.event.def.DefaultFlushEventListener.onFlush(DefaultFlushEventListener.java:51)
at org.hibernate.impl.SessionImpl.flush(SessionImpl.java:1216)
at org.hibernate.impl.SessionImpl.managedFlush(SessionImpl.java:383)
at org.hibernate.transaction.JDBCTransaction.commit(JDBCTransaction.java:133)
at de.applicodata.serviceportal.persistence.dao.GeneralDAO.commit(GeneralDAO.java:189)
at de.applicodata.serviceportal.persistence.dao.GeneralDAO.update(GeneralDAO.java:556)
at de.applicodata.serviceportal.logic.entities.Vehicle.updatePersistenceObject(Vehicle.java:509)
at de.applicodata.serviceportal.faces.beans.WerWiSalesVehicleBean.updateVehicle(WerWiSalesVehicleBean.java:1892)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.apache.el.parser.AstValue.invoke(AstValue.java:279)
at org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:273)
at org.jboss.weld.module.web.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
at org.jboss.weld.module.web.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
at com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:87)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
at net.bull.javamelody.JsfActionListener.processAction(JsfActionListener.java:67)
at javax.faces.component.UICommand.broadcast(UICommand.java:315)
at javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:790)
at javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1282)
at com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:198)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:658)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:303)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:89)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:239)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:215)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at de.applicodata.serviceportal.faces.listener.CharacterEncodingFilter.doFilter(CharacterEncodingFilter.java:36)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at de.applicodata.serviceportal.faces.listener.SessionTimeoutFilter.doFilter(SessionTimeoutFilter.java:129)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.myfaces.webapp.filter.ExtensionsFilter.doFilter(ExtensionsFilter.java:357)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at net.bull.javamelody.MonitoringFilter.doFilter(MonitoringFilter.java:199)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:241)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:208)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:219)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:110)
at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:494)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:169)
at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:104)
at org.apache.catalina.valves.AccessLogValve.invoke(AccessLogValve.java:1025)
at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:116)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:445)
at org.apache.coyote.http11.AbstractHttp11Processor.process(AbstractHttp11Processor.java:1136)
at org.apache.coyote.AbstractProtocol$AbstractConnectionHandler.process(AbstractProtocol.java:637)
at org.apache.tomcat.util.net.JIoEndpoint$SocketProcessor.run(JIoEndpoint.java:318)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
at java.lang.Thread.run(Thread.java:745)
我真的不知道从哪里开始这个，因为例外彼此如此不同。任何有关可能导致此行为的提示表示赞赏！
如果需要任何进一步的信息，我会提供。
编辑：Vehicle 错误已解决。这是由于前面提到的 Java 对象差异库中缺少一个特性。 Source
我目前正在研究一种从比较中排除数组的解决方法
答案 0 :(得分：0)
问题的第一部分得到了回答。由于 Java 对象差异库无法处理数组，我决定从比较中排除这些。
这对于像这样重写的 CanBark 方法工作得很好：
fig=plt.figure()
plt.plot(ypredicted[0:150],color="red",linewidth=2.5,linestyle="-")
plt.plot(actual[0:150],color="blue",linewidth=2.5)
编辑：第二个问题也解决了。
如果它引用了一个集合，我从 hibernate 获得的列列表是空的。因为我不需要这些列，所以我只是检查列是否可用，如果里面有列，则只迭代列数组。遗憾的是，我无法解释为什么任何集合的列数组为空。