MySQL数据库中有两个表
它们之间的关系很直观 - 从user_table到feedback的一对多。
我只需要从这些表
中获取所选列的列表@Lob装饰）执行查询需要获得许多其他许多字段。
标准查询如下。
CriteriaBuilder criteriaBuilder=entityManager.getCriteriaBuilder();
CriteriaQuery<FeedbackUtils>criteriaQuery = criteriaBuilder.createQuery(FeedbackUtils.class);
Metamodel metamodel = entityManager.getMetamodel();
EntityType<Feedback> entityType = metamodel.entity(Feedback.class);
Root<Feedback> root = criteriaQuery.from(entityType);
List<Selection<?>>selections=new ArrayList<Selection<?>>();
selections.add(root.get(Feedback_.feedbackId));
selections.add(root.get(Feedback_.feedbackTitle));
selections.add(root.get(Feedback_.feedbackDescription));
selections.add(root.get(Feedback_.feedbackDate));
selections.add(root.get(Feedback_.testimonial));
Join<Feedback, UserTable> join = root.join(Feedback_.userId, JoinType.INNER);
selections.add(join.get(UserTable_.userId));
selections.add(join.get(UserTable_.firstName));
criteriaQuery.select(criteriaBuilder.construct(FeedbackUtils.class, selections.toArray(new Selection[0])));
criteriaQuery.orderBy(criteriaBuilder.desc(root.get(Feedback_.feedbackId)));
List<FeedbackUtils>list = entityManager.createQuery(criteriaQuery).setFirstResult(first).setMaxResults(pageSize).getResultList();
FeedbackUtils类如下。
import java.io.Serializable;
import org.joda.time.DateTime;
public final class FeedbackUtils implements Serializable
{
private static final long serialVersionUID = 1L;
private Long feedbackId;
private String feedbackTitle;
private String feedbackDescription;
private DateTime feedbackDate;
private Boolean testimonial; //This causes the exception
private Long userId;
private String firstName;
public FeedbackUtils(Long feedbackId, String feedbackTitle, String feedbackDescription, DateTime feedbackDate, Boolean testimonial, Long userId, String firstName) {
this.feedbackId = feedbackId;
this.feedbackTitle = feedbackTitle;
this.feedbackDescription = feedbackDescription;
this.feedbackDate = feedbackDate;
this.testimonial = testimonial;
this.userId = userId;
this.firstName = firstName;
}
//Getters and setters.
}
testimonial实体中Feedback属性的映射如下。
@Column(name = "testimonial")
private Boolean testimonial;
它是MySQL中的一种TINYINT(1)。
尝试上述查询会导致抛出以下异常。
SEVERE: Error Rendering View[/admin_side/Feedback.xhtml]
javax.ejb.EJBException
at com.sun.ejb.containers.EJBContainerTransactionManager.processSystemException(EJBContainerTransactionManager.java:748)
at com.sun.ejb.containers.EJBContainerTransactionManager.completeNewTx(EJBContainerTransactionManager.java:698)
at com.sun.ejb.containers.EJBContainerTransactionManager.postInvokeTx(EJBContainerTransactionManager.java:503)
at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4475)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2009)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:1979)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:220)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
at $Proxy662.getList(Unknown Source)
at admin.bean.FeedbackManagedBean.load(FeedbackManagedBean.java:174)
at org.primefaces.component.datatable.DataTable.loadLazyData(DataTable.java:815)
at org.primefaces.component.datatable.DataTableRenderer.preRender(DataTableRenderer.java:93)
at org.primefaces.component.datatable.DataTableRenderer.encodeEnd(DataTableRenderer.java:81)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:85)
at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:68)
at org.primefaces.component.panel.PanelRenderer.encodeContent(PanelRenderer.java:204)
at org.primefaces.component.panel.PanelRenderer.encodeMarkup(PanelRenderer.java:121)
at org.primefaces.component.panel.PanelRenderer.encodeEnd(PanelRenderer.java:58)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1864)
at javax.faces.render.Renderer.encodeChildren(Renderer.java:176)
at javax.faces.component.UIComponentBase.encodeChildren(UIComponentBase.java:889)
at org.primefaces.renderkit.CoreRenderer.renderChild(CoreRenderer.java:81)
at org.primefaces.renderkit.CoreRenderer.renderChildren(CoreRenderer.java:68)
at org.primefaces.component.layout.LayoutUnitRenderer.encodeEnd(LayoutUnitRenderer.java:49)
at javax.faces.component.UIComponentBase.encodeEnd(UIComponentBase.java:919)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1864)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1860)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1860)
at javax.faces.component.UIComponent.encodeAll(UIComponent.java:1860)
at com.sun.faces.application.view.FaceletViewHandlingStrategy.renderView(FaceletViewHandlingStrategy.java:461)
at com.sun.faces.application.view.MultiViewHandler.renderView(MultiViewHandler.java:133)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at javax.faces.application.ViewHandlerWrapper.renderView(ViewHandlerWrapper.java:337)
at com.sun.faces.lifecycle.RenderResponsePhase.execute(RenderResponsePhase.java:120)
at com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
at com.sun.faces.lifecycle.LifecycleImpl.render(LifecycleImpl.java:219)
at javax.faces.webapp.FacesServlet.service(FacesServlet.java:647)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:344)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.primefaces.webapp.filter.FileUploadFilter.doFilter(FileUploadFilter.java:70)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at filter.NoCacheFilter.doFilter(NoCacheFilter.java:28)
at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:256)
at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:214)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:316)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:722)
Caused by: java.lang.IllegalArgumentException: An exception occured looking on class: class util.FeedbackUtils for constructor using selection criteria types as arguments. If this CriteriaQuery was not intended to be a constructor query please verify that the selection matches the return type.
at org.eclipse.persistence.internal.jpa.querydef.CriteriaQueryImpl.populateAndSetConstructorSelection(CriteriaQueryImpl.java:409)
at org.eclipse.persistence.internal.jpa.querydef.CriteriaQueryImpl.select(CriteriaQueryImpl.java:93)
at admin.beans.FeedbackBean.getList(FeedbackBean.java:145)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at org.glassfish.ejb.security.application.EJBSecurityManager.runMethod(EJBSecurityManager.java:1081)
at org.glassfish.ejb.security.application.EJBSecurityManager.invoke(EJBSecurityManager.java:1153)
at com.sun.ejb.containers.BaseContainer.invokeBeanMethod(BaseContainer.java:4695)
at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:630)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:46)
at sun.reflect.GeneratedMethodAccessor478.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:582)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.doCall(SystemInterceptorProxy.java:163)
at com.sun.ejb.containers.interceptors.SystemInterceptorProxy.aroundInvoke(SystemInterceptorProxy.java:140)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:601)
at com.sun.ejb.containers.interceptors.AroundInvokeInterceptor.intercept(InterceptorManager.java:883)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
at com.sun.ejb.containers.interceptors.InterceptorManager.intercept(InterceptorManager.java:369)
at com.sun.ejb.containers.BaseContainer.__intercept(BaseContainer.java:4667)
at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4655)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
... 67 more
Caused by: java.lang.NoSuchMethodException: util.FeedbackUtils.<init>(java.lang.Long, java.lang.String, java.lang.String, org.joda.time.DateTime, java.lang.Boolean, java.lang.Long, java.lang.String)
at java.lang.Class.getConstructor0(Class.java:2721)
at java.lang.Class.getConstructor(Class.java:1674)
at org.eclipse.persistence.internal.security.PrivilegedAccessHelper.getConstructorFor(PrivilegedAccessHelper.java:157)
at org.eclipse.persistence.internal.jpa.querydef.CriteriaQueryImpl.populateAndSetConstructorSelection(CriteriaQueryImpl.java:396)
... 98 more
当testimonial类中Boolean的类型从Object更改为FeedbackUtils时，此方法正常。
如果在构造函数参数列表中给出Boolean类型，它为什么不让构造函数查询起作用？
我正在使用EclipseLink 2.5.1。
编辑：
在FeedbackUtils类的构造函数中，进行以下检查，
testimonial.getClass().getName()
返回java.lang.Boolean
以及以下所有内容，
(testimonial instanceof Boolean)
testimonial.getClass().equals(Boolean.class)
testimonial.getClass().isAssignableFrom(Boolean.class)
返回true。
因此，以下类型转换也是有效的。
(Boolean)testimonial
在关联的XHTML页面上，它的行为与Boolean一样正确。