我几天来一直在尝试弄清楚如何从 map 中删除持久元素。我发现了有类似问题的线程，但最终没有一个能帮助我。 一切工作正常，添加和保留元素，编辑和更新该元素等等。除了删除元素。我有一个(时间)时间表，每个工作日都有 5 张 map 。这是代码的基本部分
时间表:
@Entity
public class Schedule extends JPAEntity implements Serializable {
...
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "id")
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> monday;
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "id")
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> tuesday;
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "id")
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> wednesday;
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "id")
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> thursday;
@OneToMany(mappedBy = "schedule", cascade = CascadeType.ALL, orphanRemoval = true)
@JoinColumn(name = "id")
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> friday;
public boolean removeSubject(final int index, final SchoolSubject oldSubject) {
final String day = oldSubject.getWeekday();
switch (day) {
case "Montag":
return monday.remove(index, oldSubject);
case "Dienstag":
return tuesday.remove(index, oldSubject);
case "Mittwoch":
return wednesday.remove(index, oldSubject);
case "Donnerstag":
return thursday.remove(index, oldSubject);
case "Freitag":
return friday.remove(index, oldSubject);
}
return false;
}
学校主题:
@Entity
public class SchoolSubject extends JPAEntity implements Serializable {
private static final long serialVersionUID = -3554577133392512324L;
@Column(nullable = false)
private String name;
@Basic
@Column(nullable = false)
private int hourTime;
@ManyToOne(optional = false)
private Schedule schedule;
JPA实体:
@MappedSuperclass
@EntityListeners(JPAEntityListener.class)
public class JPAEntity {
@Id
@GeneratedValue
private Long id;
所以我在另一个逻辑类中的删除方法如下:
@Override
public void removeSubject(User user, Schedule schedule, SchoolSubject oldSubject) {
if (schedule.removeSubject(oldSubject.getHourTime() - 1, oldSubject)) {
schoolSubjectDAO.remove(oldSubject);
}
scheduleDAO.update(schedule);
try {
userDAO.update(user);
} catch (final DuplicateUniqueFieldException e) {
throw new UnexpectedUniqueViolationException(e);
}
}
我正在调试该方法，我成功地从计划中删除了该元素。但 scheduleDAO.update(schedule) 似乎无法完全正常工作。就像我说的，其他一切都完美无缺
更新
我现在遵循了 crizzis 的建议，将其更改为单向关系，并删除了 SchoolSubject.schedule 字段。
更新的 Schedule 类:
@Entity
public class Schedule extends JPAEntity implements Serializable {
/**
* Die eindeutige SerialisierungsID.
*/
private static final long serialVersionUID = -3554837193392512324L;
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> monday;
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> tuesday;
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> wednesday;
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> thursday;
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> friday;
但是这样我在添加主题时遇到了一个新错误(以前有效)。添加操作如下:
public void addSubject(User user, Schedule schedule, SchoolSubject subject)
throws DateAlreadyOccupiedException {
schedule.addSubject(subject.getHourTime() - 1, subject);
scheduleDAO.update(schedule);
try {
userDAO.update(user);
} catch (final DuplicateUniqueFieldException e) {
throw new UnexpectedUniqueViolationException(e);
}
}
我得到的错误如下:
Severe: javax.faces.el.EvaluationException: javax.ejb.EJBTransactionRolledbackException
at javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:101)
at com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
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.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 de.unibremen.st.gradelog.filter.AuthorizationFilter.doFilter(AuthorizationFilter.java:94)
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:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.ejb.EJBTransactionRolledbackException
at com.sun.ejb.containers.BaseContainer.mapLocal3xException(BaseContainer.java:2342)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2123)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2044)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:220)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
at com.sun.proxy.$Proxy613.update(Unknown Source)
at de.unibremen.st.gradelog.persistence.__EJB31_Generated__UserDAO__Intf____Bean__.update(Unknown Source)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:434)
at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:127)
at org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
at org.jboss.weld.bean.proxy.InjectionPointPropagatingEnterpriseTargetBeanInstance.invoke(InjectionPointPropagatingEnterpriseTargetBeanInstance.java:67)
at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:100)
at de.unibremen.st.gradelog.persistence.UserDAO$Proxy$_$$_Weld$EnterpriseProxy$.update(Unknown Source)
at de.unibremen.st.gradelog.businesslogic.ScheduleManager.addSubject(ScheduleManager.java:56)
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.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:4786)
at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
at sun.reflect.GeneratedMethodAccessor86.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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:608)
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.GeneratedMethodAccessor93.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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:4758)
at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
at com.sun.proxy.$Proxy605.addSubject(Unknown Source)
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.jboss.weld.util.reflection.Reflections.invokeAndUnwrap(Reflections.java:434)
at org.jboss.weld.bean.proxy.EnterpriseBeanProxyMethodHandler.invoke(EnterpriseBeanProxyMethodHandler.java:127)
at org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
at org.jboss.weld.bean.proxy.InjectionPointPropagatingEnterpriseTargetBeanInstance.invoke(InjectionPointPropagatingEnterpriseTargetBeanInstance.java:67)
at org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:100)
at de.unibremen.st.gradelog.businesslogic.IScheduleManager$1688850411$Proxy$_$$_Weld$EnterpriseProxy$.addSubject(Unknown Source)
at de.unibremen.st.gradelog.controller.ScheduleBean.save(ScheduleBean.java:100)
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 com.sun.el.parser.AstValue.invoke(AstValue.java:289)
at com.sun.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:304)
at org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:40)
at org.jboss.weld.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)
... 41 more
Caused by: javax.ejb.TransactionRolledbackLocalException: Exception thrown from bean
at com.sun.ejb.containers.EJBContainerTransactionManager.checkExceptionClientTx(EJBContainerTransactionManager.java:666)
at com.sun.ejb.containers.EJBContainerTransactionManager.postInvokeTx(EJBContainerTransactionManager.java:511)
at com.sun.ejb.containers.BaseContainer.postInvokeTx(BaseContainer.java:4566)
at com.sun.ejb.containers.BaseContainer.postInvoke(BaseContainer.java:2074)
... 109 more
Caused by: javax.persistence.PersistenceException: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150605-31e8258): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID' cannot accept a NULL value.
Error Code: 20000
Call: INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)
bind => [2 parameters bound]
Query: DataModifyQuery(name="monday" sql="INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)")
at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:879)
at org.eclipse.persistence.internal.jpa.QueryImpl.performPreQueryFlush(QueryImpl.java:967)
at org.eclipse.persistence.internal.jpa.QueryImpl.executeReadQuery(QueryImpl.java:207)
at org.eclipse.persistence.internal.jpa.QueryImpl.getResultList(QueryImpl.java:473)
at de.unibremen.st.gradelog.persistence.UserDAO.getUserForUsername(UserDAO.java:227)
at de.unibremen.st.gradelog.persistence.UserDAO.update(UserDAO.java:151)
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.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:4786)
at com.sun.ejb.EjbInvocation.invokeBeanMethod(EjbInvocation.java:656)
at com.sun.ejb.containers.interceptors.AroundInvokeChainImpl.invokeNext(InterceptorManager.java:822)
at com.sun.ejb.EjbInvocation.proceed(EjbInvocation.java:608)
at org.jboss.weld.ejb.AbstractEJBRequestScopeActivationInterceptor.aroundInvoke(AbstractEJBRequestScopeActivationInterceptor.java:64)
at org.jboss.weld.ejb.SessionBeanInterceptor.aroundInvoke(SessionBeanInterceptor.java:52)
at sun.reflect.GeneratedMethodAccessor86.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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:608)
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.GeneratedMethodAccessor93.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
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:4758)
at com.sun.ejb.containers.BaseContainer.intercept(BaseContainer.java:4746)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:212)
... 107 more
Caused by: Exception [EclipseLink-4002] (Eclipse Persistence Services - 2.6.1.v20150605-31e8258): org.eclipse.persistence.exceptions.DatabaseException
Internal Exception: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID' cannot accept a NULL value.
Error Code: 20000
Call: INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)
bind => [2 parameters bound]
Query: DataModifyQuery(name="monday" sql="INSERT INTO SCHEDULE_SCHOOLSUBJECT (monday_ID, Schedule_ID) VALUES (?, ?)")
at org.eclipse.persistence.exceptions.DatabaseException.sqlException(DatabaseException.java:331)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:902)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeNoSelect(DatabaseAccessor.java:964)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.basicExecuteCall(DatabaseAccessor.java:633)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeCall(DatabaseAccessor.java:560)
at org.eclipse.persistence.internal.sessions.AbstractSession.basicExecuteCall(AbstractSession.java:2055)
at org.eclipse.persistence.sessions.server.ClientSession.executeCall(ClientSession.java:306)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:242)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeCall(DatasourceCallQueryMechanism.java:228)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeNoSelectCall(DatasourceCallQueryMechanism.java:271)
at org.eclipse.persistence.internal.queries.DatasourceCallQueryMechanism.executeNoSelect(DatasourceCallQueryMechanism.java:251)
at org.eclipse.persistence.internal.queries.StatementQueryMechanism.executeNoSelect(StatementQueryMechanism.java:118)
at org.eclipse.persistence.queries.DataModifyQuery.executeDatabaseQuery(DataModifyQuery.java:85)
at org.eclipse.persistence.queries.DatabaseQuery.execute(DatabaseQuery.java:904)
at org.eclipse.persistence.internal.sessions.AbstractSession.internalExecuteQuery(AbstractSession.java:3267)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1857)
at org.eclipse.persistence.internal.sessions.AbstractSession.executeQuery(AbstractSession.java:1839)
at org.eclipse.persistence.mappings.ManyToManyMapping.insertAddedObjectEntry(ManyToManyMapping.java:630)
at org.eclipse.persistence.mappings.ManyToManyMapping.performDataModificationEvent(ManyToManyMapping.java:838)
at org.eclipse.persistence.internal.sessions.CommitManager.commitAllObjectsWithChangeSet(CommitManager.java:160)
at org.eclipse.persistence.internal.sessions.AbstractSession.writeAllObjectsWithChangeSet(AbstractSession.java:4260)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabase(UnitOfWorkImpl.java:1441)
at org.eclipse.persistence.internal.sessions.UnitOfWorkImpl.commitToDatabaseWithPreBuiltChangeSet(UnitOfWorkImpl.java:1587)
at org.eclipse.persistence.internal.sessions.RepeatableWriteUnitOfWork.writeChanges(RepeatableWriteUnitOfWork.java:455)
at org.eclipse.persistence.internal.jpa.EntityManagerImpl.flush(EntityManagerImpl.java:874)
... 141 more
Caused by: java.sql.SQLIntegrityConstraintViolationException: Column 'FRIDAY_ID' cannot accept a NULL value.
at org.apache.derby.client.am.SQLExceptionFactory40.getSQLException(Unknown Source)
at org.apache.derby.client.am.SqlException.getSQLException(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.executeUpdate(Unknown Source)
at com.sun.gjc.spi.base.PreparedStatementWrapper.executeUpdate(PreparedStatementWrapper.java:125)
at org.eclipse.persistence.internal.databaseaccess.DatabaseAccessor.executeDirectNoSelect(DatabaseAccessor.java:892)
... 164 more
Caused by: org.apache.derby.client.am.SqlException: Column 'FRIDAY_ID' cannot accept a NULL value.
at org.apache.derby.client.am.Statement.completeExecute(Unknown Source)
at org.apache.derby.client.net.NetStatementReply.parseEXCSQLSTTreply(Unknown Source)
at org.apache.derby.client.net.NetStatementReply.readExecute(Unknown Source)
at org.apache.derby.client.net.StatementReply.readExecute(Unknown Source)
at org.apache.derby.client.net.NetPreparedStatement.readExecute_(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.readExecute(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.flowExecute(Unknown Source)
at org.apache.derby.client.am.PreparedStatement.executeUpdateX(Unknown Source)
... 167 more
最佳答案
你不能像这样重用mappedBy。在持久化 Schedule 并尝试从数据库加载它后，JPA 无法知道哪个 SchoolSubject 实体转到 monday，哪个那些去星期二等等。您想要做的是将关系的一侧 (SchoolSubject.schedule) 映射到多个相反的一侧 (Schedule.monday、Schedule.tuesday, ... )。这在 JPA 中是非法的。
我能想到的实现您想要的映射的唯一方法是使用单向关系(最好没有连接列)，如下所示:
@OneToMany(cascade = CascadeType.ALL, orphanRemoval = true)
@MapKey(name = "hourTime")
private Map<Integer, SchoolSubject> monday;
...
您还需要完全删除 SchoolSubject.schedule 字段(作为替代方案，为了保持双向关系，您需要每天在 SchoolSubject 中添加一个字段周，但我猜这不是你想要的)。
这样，JPA 会将 Schedule 和 SchoolSubject 之间的关系保存在单独的联接表中，一周中的每一天都有一个(这样它们就不会混合在一起)向上)。如果您绝对需要连接列方法，请为每个映射使用单独的连接列(monday_id、tuesday_id 等)(请勿不要使用相同的列名，并且不使用主键列，我假设名为 id 的列是)。
关于java - 使用 jpa 删除 map 的元素，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/42341007/