Question

Here you can see the entity-relationship diagram of my database with associations

我正在NetBeans中使用Apache Derby开发一个Hibernate库存管理程序。该应用程序将要求用户从合作伙伴数据库中预先输入的项目/合作伙伴中进行选择，然后输入日期（请参见上方的ERD）。用户可以选择从库存进货还是出库。假设这将在Advicenote表中创建一个Advicenote条目，如下所示：

Selection user interface

然后，在下一个窗口中，用户将能够实际设置与通知相关的Transaction的值：

Next input window

这是带有实现此目的的侦听器的代码：

private void deliveryButtonActionPerformed(java.awt.event.ActionEvent evt) {                                               
    session = sessionFactory.openSession();
    transaction = session.beginTransaction();
    advice.setAdvicedate((Date) this.dateSpinner.getValue());
    advice.setInOrOut((short)1);
    Criteria criteria = session.createCriteria(Partner.class);
    partner = (Partner) criteria.add(Restrictions.eq("partnerName", this.partnerComboBox.getSelectedItem())).uniqueResult();
    System.out.println("partner");
    advice.setPartner(partner);
    session.save(advice);
    transaction.commit();
    session.close();
    delivery.setVisible(true);
}                                              

private void transferButtonActionPerformed(java.awt.event.ActionEvent evt) {                                               
    session = sessionFactory.openSession();
    transaction = session.beginTransaction();
    advice.setAdvicedate((Date) this.dateSpinner.getValue());
    advice.setInOrOut((short)-1);
    Criteria criteria = session.createCriteria(Partner.class);
    partner = (Partner) criteria.add(Restrictions.eq("partnerName", this.partnerComboBox.getSelectedItem().toString())).uniqueResult();
    advice.setPartner(partner);
    session.save(advice);
    transaction.commit();
    session.close();
    transfer.setVisible(true);
}

以下是这些类的XML映射文件：

合作伙伴课程

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">

<hibernate-mapping>
    <class name="classes.Partner" table="PARTNER" schema="APP">
        <id name="partnerId" type="int">
            <column name="PARTNER_ID"/>
            <generator class="native"/>
        </id>
        <property name="partnerName" type="string" column="PARTNER_NAME" length="100"/>
        <set name="advicenotes" table="ADVICENOTE" inverse="false" cascade="all" lazy="true" fetch="select">
            <key column="PARTNER_ID" not-null="true"/>
            <one-to-many class="classes.Advicenote" />
        </set>
            </class>
</hibernate-mapping>

通知单班

<?xml version="1.0"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
"http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<!-- Generated Feb 9, 2019, 3:57:52 PM by Hibernate Tools 4.3.1 -->
<hibernate-mapping>
    <class name="classes.Advicenote" table="ADVICENOTE" schema="APP" optimistic-lock="version">
        <id name="advicenoteId" type="int" column="ADVICENOTE_ID">
            <generator class="native" />
        </id>
        <property name="advicedate" type="date" column="ADVICE_DATE" length="10" />
        <property name="inOrOut" type="java.lang.Short" column="IN_OR_OUT" />
        <many-to-one 
            name="partner" class="classes.Partner"/>  
        <set name="transactions" table="TRANSACTIONS" inverse="false" cascade="all" lazy="true" fetch="select">       
            <key column="ADVICENOTE_ID" not-null="true"/>
            <one-to-many class="classes.Transactions"/>
        </set>
    </class>
</hibernate-mapping>

但是，我收到此错误：

线程“ AWT-EventQueue-0”中的异常 org.hibernate.PropertyValueException：非null属性引用一个空值或瞬时值： classes.Advicenote._classes.Partner.advicenotesBackref位于 org.hibernate.engine.internal.Nullability.checkNullability（Nullability.java:111）在 org.hibernate.engine.internal.Nullability.checkNullability（Nullability.java:55）在 org.hibernate.action.internal.AbstractEntityInsertAction.nullifyTransientReferencesIfNotAlready（AbstractEntityInsertAction.java:115）在 org.hibernate.action.internal.EntityIdentityInsertAction.execute（EntityIdentityInsertAction.java:69）在org.hibernate.engine.spi.ActionQueue.execute（ActionQueue.java:645）在 org.hibernate.engine.spi.ActionQueue.addResolvedEntityInsertAction（ActionQueue.java:282）在 org.hibernate.engine.spi.ActionQueue.addInsertAction（ActionQueue.java:263）在 org.hibernate.engine.spi.ActionQueue.addAction（ActionQueue.java:317）在 org.hibernate.event.internal.AbstractSaveEventListener.addInsertAction（AbstractSaveEventListener.java:332）在 org.hibernate.event.internal.AbstractSaveEventListener.performSaveOrReplicate（AbstractSaveEventListener.java:289）在 org.hibernate.event.internal.AbstractSaveEventListener.performSave（AbstractSaveEventListener.java:196）在 org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId（AbstractSaveEventListener.java:127）在 org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId（DefaultSaveOrUpdateEventListener.java:192）在 org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId（DefaultSaveEventListener.java:38）在 org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient（DefaultSaveOrUpdateEventListener.java:177）在 org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate（DefaultSaveEventListener.java:32）在 org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate（DefaultSaveOrUpdateEventListener.java:73）在org.hibernate.internal.SessionImpl.fireSave（SessionImpl.java:713）在org.hibernate.internal.SessionImpl.save（SessionImpl.java:705）处 org.hibernate.internal.SessionImpl.save（SessionImpl.java:700）在 delivery.view.Selection.deliveryButtonActionPerformed（Selection.java:190）在delivery.view.Selection $ 2.actionPerformed（Selection.java:106）在 java.desktop / javax.swing.AbstractButton.fireActionPerformed（AbstractButton.java:1967）在 java.desktop / javax.swing.AbstractButton $ Handler.actionPerformed（AbstractButton.java:2308）在 java.desktop / javax.swing.DefaultButtonModel.fireActionPerformed（DefaultButtonModel.java:405）在 java.desktop / javax.swing.DefaultButtonModel.setPressed（DefaultButtonModel.java:262）在 java.desktop / javax.swing.plaf.basic.BasicButtonListener.mouseReleased（BasicButtonListener.java:279）在 java.desktop / java.awt.AWTEventMulticaster.mouseReleased（AWTEventMulticaster.java:297）在 java.desktop / java.awt.Component.processMouseEvent（Component.java:6632）在 java.desktop / javax.swing.JComponent.processMouseEvent（JComponent.java:3342）在java.desktop / java.awt.Component.processEvent（Component.java:6397）在java.desktop / java.awt.Container.processEvent（Container.java:2263）在 java.desktop / java.awt.Component.dispatchEventImpl（Component.java:5008）在 java.desktop / java.awt.Container.dispatchEventImpl（Container.java:2321）在java.desktop / java.awt.Component.dispatchEvent（Component.java:4840）在 java.desktop / java.awt.LightweightDispatcher.retargetMouseEvent（Container.java:4918）在 java.desktop / java.awt.LightweightDispatcher.processMouseEvent（Container.java:4547）在 java.desktop / java.awt.LightweightDispatcher.dispatchEvent（Container.java:4488）在 java.desktop / java.awt.Container.dispatchEventImpl（Container.java:2307）在java.desktop / java.awt.Window.dispatchEventImpl（Window.java:2772）在java.desktop / java.awt.Component.dispatchEvent（Component.java:4840）在 java.desktop / java.awt.EventQueue.dispatchEventImpl（EventQueue.java:772）在java.desktop / java.awt.EventQueue $ 4.run（EventQueue.java:721）在 java.desktop / java.awt.EventQueue $ 4.run（EventQueue.java:715）在 java.base / java.security.AccessController.doPrivileged（本机方法）在 java.base / java.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege（ProtectionDomain.java:85）在 java.base / java.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege（ProtectionDomain.java:95）在java.desktop / java.awt.EventQueue $ 5.run（EventQueue.java:745）在 java.desktop / java.awt.EventQueue $ 5.run（EventQueue.java:743）在 java.base / java.security.AccessController.doPrivileged（本机方法）在 java.base / java.security.ProtectionDomain $ JavaSecurityAccessImpl.doIntersectionPrivilege（ProtectionDomain.java:85）在 java.desktop / java.awt.EventQueue.dispatchEvent（EventQueue.java:742）在 java.desktop / java.awt.EventDispatchThread.pumpOneEventForFilters（EventDispatchThread.java:203）在 java.desktop / java.awt.EventDispatchThread.pumpEventsForFilter（EventDispatchThread.java:124）在 java.desktop / java.awt.EventDispatchThread.pumpEventsForHierarchy（EventDispatchThread.java:113）在 java.desktop / java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:109）在 java.desktop / java.awt.EventDispatchThread.pumpEvents（EventDispatchThread.java:101）在 java.desktop / java.awt.EventDispatchThread.run（EventDispatchThread.java:90）

我已经尝试了很多年了，但是没有运气。我会尽力帮助您！

Answer 1

您已定义了双向映射，但只设置了一侧。

您必须在partner中设置AdviceNote，并在advicenotes上填写Partner集：

advice.setPartner(partner);
partner.getAdviceNotes().add(advice);
session.save(advice);
transaction.commit();

休眠异常“ PropertyValueException：非null属性引用一个> null或瞬时值”。我被困住了，不知道该怎么办

1 个答案: