Question

当我运行下面的代码以显示属于JTable中特定类别的项目时，我收到此异常：

private void categoryComboBoxActionPerformed(java.awt.event.ActionEvent evt) {                                                 
                try {
        DefaultTableModel dtm = new DefaultTableModel();
        String cat = this.categoryComboBox.getSelectedItem().toString();
        session=sessionFactory.openSession();
        transaction = session.beginTransaction();
        Criteria criteria = session.createCriteria(Items.class);
//HERE LIES THE PROBLEM BUT I HAVE NO CLUE HOW TO SOLVE IT
        List<Items> itemlist = criteria.add(Restrictions.eq("category", cat).ignoreCase()).list();
        transaction.commit();
        session.close();

            if (dtm.getColumnCount()==0) {
            dtm.addColumn("Name");
            dtm.addColumn("Category");
            dtm.addColumn("Quantity");
            dtm.addColumn("Net Price (per unit)");
            dtm.addColumn("Gross Pice (per unit)");
            dtm.addColumn("Net Price (total)");
            dtm.addColumn("Gross Price (total)");
            }
            Font f = new Font("Georgia", Font.BOLD, 16);      
            JTableHeader header = itemTable.getTableHeader();
            header.setFont(f);
            itemTable.setRowHeight(25);

            if (getQuantity().isEmpty()) {for (int i = 0; i < itemlist.size(); i++) {
                     dtm.addRow(new Object[]{itemlist.get(i).getName(), itemlist.get(i).getCategory().getName(),"-",itemlist.get(i).getNetPrice(), Math.round((Double.valueOf(itemlist.get(i).getNetPrice())*(1d+itemlist.get(i).getVatRate()/100d))), "-", "-"});
                }

            } else {
                for (int i = 0; i < itemlist.size(); i++) {
                    dtm.addRow(new Object[]{itemlist.get(i).getName(), itemlist.get(i).getCategory().getName(), getQuantity().get(itemlist.get(i).getItemId()).getQuantity(), itemlist.get(i).getNetPrice(), itemlist.get(i).getNetPrice()*(itemlist.get(i).getVatRate()+1), getQuantity().get(itemlist.get(i).getItemId()).getQuantity()*itemlist.get(i).getNetPrice(), itemlist.get(i).getNetPrice()*(itemlist.get(i).getVatRate()+1)*getQuantity().get(itemlist.get(i).getItemId()).getQuantity()});
                }

            }

          this.itemTable.setModel(dtm);} catch (Exception e) {
         JOptionPane.showMessageDialog(null, e.getMessage()); 
         e.printStackTrace();
    }
}

这也是我的XML映射类：

Caregories.hbm.xml

<?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.Categories" table="CATEGORIES" schema="APP" optimistic-lock="version">
        <id name="categoryId" type="int">
            <column name="CATEGORY_ID" />
            <generator class="native" />
        </id>
        <property name="name" type="string">
            <column name="NAME" length="100" />
        </property>
     <set name="items" table="ITEMS" inverse="false" cascade="all" lazy="false" fetch="select">
        <key>
            <column name="CATEGORY_ID" not-null="true" />
        </key>
        <one-to-many class="classes.Items" />
    </set>
    </class>
</hibernate-mapping>

Items.hbm.xml

<?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.Items" table="ITEMS" schema="APP" optimistic-lock="version">
        <id name="itemId" type="int" column="ITEM_ID">
            <generator class="native" />
        </id>
        <property name="name" type="string" column="NAME" length="100"/>
        <property name="netPrice" type="java.lang.Integer" column="NET_PRICE"/>
        <property name="vatRate" type="java.lang.Integer" column="VAT_RATE"/>
        <many-to-one name="category" class="classes.Categories" fetch="select" column="CATEGORY_ID" not-null="true" lazy="false"/>
    </class>
</hibernate-mapping>

这是我数据库的实体关系图

Categories.java

package classes;
// Generated Feb 9, 2019, 3:57:50 PM by Hibernate Tools 4.3.1

import java.util.Set;

public class Categories  implements java.io.Serializable {


     private int categoryId;
     private String name;
     private Set<Items> items;

    public Categories() {
    }

    public Categories(int categoryId, String name, Set<Items> items) {
        this.categoryId = categoryId;
        this.name = name;
        this.items = items;
    }  


    public int getCategoryId() {
        return this.categoryId;
    }

    public void setCategoryId(int categoryId) {
        this.categoryId = categoryId;
    }
    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Set<Items> getItems() {
        return items;
    }

    public void setItems(Set<Items> items) {
        this.items = items;
    }


}

Items.java

package classes;

public class Items  implements java.io.Serializable {


     private int itemId;
     private String name;
     private Integer netPrice;
     private Integer vatRate;
     private Categories category;

    public Items() {
    }

    public Items(int itemId, String name, Integer netPrice, Integer vatRate, Categories category) {
        this.itemId = itemId;
        this.name = name;
        this.netPrice = netPrice;
        this.vatRate = vatRate;
        this.category = category;
    }

    public int getItemId() {
        return this.itemId;
    }

    public void setItemId(int itemId) {
        this.itemId = itemId;
    }
    public String getName() {
        return this.name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public Integer getNetPrice() {
        return this.netPrice;
    }

    public void setNetPrice(Integer netPrice) {
        this.netPrice = netPrice;
    }
    public Integer getVatRate() {
        return this.vatRate;
    }

    public void setVatRate(Integer vatRate) {
        this.vatRate = vatRate;
    }

    public Categories getCategory() {
        return category;
    }

    public void setCategory(Categories category) {
        this.category = category;
    }


}

org.hibernate.PropertyAccessException：IllegalArgumentException 发生在调用class.Categories.categoryId的getter org.hibernate.property.access.spi.GetterMethodImpl.get（GetterMethodImpl.java:65）在 org.hibernate.tuple.entity.AbstractEntityTuplizer.getIdentifier（AbstractEntityTuplizer.java:224）在 org.hibernate.persister.entity.AbstractEntityPersister.getIdentifier（AbstractEntityPersister.java:4933）在 org.hibernate.persister.entity.AbstractEntityPersister.isTransient（AbstractEntityPersister.java:4633）在 org.hibernate.engine.internal.ForeignKeys.isTransient（ForeignKeys.java:226）在 org.hibernate.engine.internal.ForeignKeys.getEntityIdentifierIfNotUnsaved（ForeignKeys.java:276）在org.hibernate.type.EntityType.getIdentifier（EntityType.java:495）在org.hibernate.type.EntityType.nullSafeSet（EntityType.java:288）处 org.hibernate.loader.Loader.bindPositionalParameters（Loader.java:2102）在org.hibernate.loader.Loader.bindParameterValues（Loader.java:2071）在 org.hibernate.loader.Loader.prepareQueryStatement（Loader.java:2006）在 org.hibernate.loader.Loader.executeQueryStatement（Loader.java:1920）在 org.hibernate.loader.Loader.executeQueryStatement（Loader.java:1898）在org.hibernate.loader.Loader.doQuery（Loader.java:937）处 org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections（Loader.java:340）在org.hibernate.loader.Loader.doList（Loader.java:2695）处 org.hibernate.loader.Loader.doList（Loader.java:2678）在 org.hibernate.loader.Loader.listIgnoreQueryCache（Loader.java:2512）在 org.hibernate.loader.Loader.list（Loader.java:2507）在 org.hibernate.loader.criteria.CriteriaLoader.list（CriteriaLoader.java:109）在org.hibernate.internal.SessionImpl.list（SessionImpl.java:1999）处 org.hibernate.internal.CriteriaImpl.list（CriteriaImpl.java:370）位于 stock.view.StockView.categoryComboBoxActionPerformed（StockView.java:530）在 stock.view.StockView $ FormListener.actionPerformed（StockView.java:344）在 java.desktop / javax.swing.JComboBox.fireActionEvent（JComboBox.java:1264）在 java.desktop / javax.swing.JComboBox.contentsChanged（JComboBox.java:1337）在 java.desktop / javax.swing.AbstractListModel.fireContentsChanged（AbstractListModel.java:123）在 java.desktop / javax.swing.DefaultComboBoxModel.setSelectedItem（DefaultComboBoxModel.java:94）在 java.desktop / javax.swing.DefaultComboBoxModel.addElement（DefaultComboBoxModel.java:132）在java.desktop / javax.swing.JComboBox.addItem（JComboBox.java:716）处 stock.view.StockView.FillUpComboBox（StockView.java:103）在 stock.view.StockView。（StockView.java:41）在 main.view.MainMenu.stockMenuItemActionPerformed（MainMenu.java:290）位于 main.view.MainMenu $ FormListener.actionPerformed（MainMenu.java:240）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.AbstractButton.doClick（AbstractButton.java:369）在 java.desktop / javax.swing.plaf.basic.BasicMenuItemUI.doClick（BasicMenuItemUI.java:1020）在 java.desktop / javax.swing.plaf.basic.BasicMenuItemUI $ Handler.mouseReleased（BasicMenuItemUI.java:1064）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）原因：java.lang.IllegalArgumentException：对象不是在声明类的实例 java.base / jdk.internal.reflect.NativeMethodAccessorImpl.invoke0（本机方法） java.base / jdk.internal.reflect.NativeMethodAccessorImpl.invoke（NativeMethodAccessorImpl.java:62）在 java.base / jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke（DelegatingMethodAccessorImpl.java:43）在java.base / java.lang.reflect.Method.invoke（Method.java:566）在 org.hibernate.property.access.spi.GetterMethodImpl.get（GetterMethodImpl.java:42） ...还有71

Answer 1

criteria.add(Restrictions.eq("category", cat).ignoreCase())，这是错误的。您无法将关系与字符串进行比较。以下是直接来自Hibernate文档的示例：

List<Items> itemlist = sess.createCriteria(Items.class)      
    .createAlias("category",c)
        .add( Restrictions.eq("c.name", cat))
    .list();

https://docs.jboss.org/hibernate/orm/3.3/reference/en/html/querycriteria.html

另一个观察结果是您正在使用inverse = false。 IMO，您希望它是inverse = true

Hibernate PropertyAccessException：发生IllegalArgumentException调用getter吗？发生了什么事？

1 个答案: