Question

我正在尝试将数据保存在不同的表中因为我正在编写主要方法在这里我想保存BillDetails bd，以及CustomerDetails cd（如果存在更新，否则插入）和BillProductDetails bpd，同时保存它是异常 Exception in thread "main" org.hibernate.id.IdentifierGenerationException: null id generated for:class iland.hbm.BillProductDetails

 public static void main(String[] s) {
        BillDetails bd = new BillDetails();
        bd.setPaymentType("Cash");
        DatenTime dnt = new DatenTime();
        bd.setAddDate(dnt.getTimeStamp());
        bd.setSubTotal(400f);
        bd.setVat(20f);
        bd.setTotal(420f);
        /*Customer details*/
        CustomerDetails cd = new CustomerDetails();
        cd.setId(107L);
        cd.setName("Nita");
        cd.setAddress("India");
        cd.setDob(new Date(2014, 11, 1));
        cd.setAnniversery(new Date(2014, 11, 1));
        bd.setCustomerDetails(cd);
        /*Bill Product Details*/
        BillProductDetails bpd = new BillProductDetails();
        bpd.setQty(4);
        bpd.setSellingPrice(420.0F);
        bpd.setUnitPrice(400.0F);
        bpd.setDiscountPercent(10);
        ProductDetails pd = new ProductDetails();
        pd.setBarcode("111");
        pd.setId(1001L);
        bpd.setProductDetails(pd);
        bpd.setBillDetails(bd);
        bd.getBillProductList().add(bpd);
        BillDAO dao = new BillDAO();
        dao.insert(bd);

    }

BillDetails.hbm.xml

<hibernate-mapping>
    <class name="iland.hbm.BillDetails" table="bill_details" catalog="retail_shop">
        <id name="billNo" type="java.lang.Long">
            <column name="bill_no" />
            <generator class="identity" />
        </id>
        <many-to-one name="customerDetails" class="iland.hbm.CustomerDetails" fetch="select" cascade="all">
            <column name="customer_id" not-null="true" />
        </many-to-one>
        <many-to-one name="client" class="iland.hbm.Client" fetch="select" cascade="all">
            <column name="cid" not-null="true" />
        </many-to-one>
        <property name="subTotal" type="big_decimal">
            <column name="sub_total" precision="15" />
        </property>
        <property name="vat" type="big_decimal">
            <column name="vat" precision="15" />
        </property>
        <property name="total" type="big_decimal">
            <column name="total" precision="15" />
        </property>
        <property name="paymentType" type="string">
            <column name="payment_type" length="30" not-null="true" />
        </property>
        <property name="status" type="string">
            <column name="status" length="20" />
        </property>
        <property name="addDate" type="timestamp">
            <column name="add_date" length="19" not-null="true" />
        </property>
        <bag name="billProductList" table="bill_product_details" inverse="true" lazy="false" fetch="join" cascade="all">
            <key>
                <column name="bill_no" not-null="true" />
            </key>
            <one-to-many class="iland.hbm.BillProductDetails" />
        </bag>
        <set name="billPaidDetailses" table="bill_paid_details" inverse="true" lazy="false" fetch="join" cascade="all">
            <key>
                <column name="bill_no" not-null="true" />
            </key>
            <one-to-many class="iland.hbm.BillPaidDetails" />
        </set>
    </class>
</hibernate-mapping>

BillProductDetails.hbm.xml

<hibernate-mapping>
    <class name="iland.hbm.BillProductDetails" table="bill_product_details" catalog="retail_shop">
        <composite-id name="id" class="iland.hbm.BillProductDetailsId">
            <key-property name="productId" type="long">
                <column name="product_id" />
            </key-property>
            <key-property name="billNo" type="long">
                <column name="bill_no" />
            </key-property>
        </composite-id>
        <many-to-one name="client" class="iland.hbm.Client" fetch="select">
            <column name="cid" not-null="true" />
        </many-to-one>
        <many-to-one name="billDetails" class="iland.hbm.BillDetails" update="false" insert="false" fetch="select">
            <column name="bill_no" not-null="true" />
        </many-to-one>
        <many-to-one name="productDetails" class="iland.hbm.ProductDetails" update="false" insert="false" fetch="select">
            <column name="product_id" not-null="true" />
        </many-to-one>
        <property name="qty" type="long">
            <column name="qty" not-null="true" />
        </property>
        <property name="unitPrice" type="big_decimal">
            <column name="unit_price" precision="15" not-null="true" />
        </property>
        <property name="sellingPrice" type="big_decimal">
            <column name="selling_price" precision="15" not-null="true" />
        </property>
        <property name="discountPercent" type="java.lang.Integer">
            <column name="discount_percent" />
        </property>
    </class>
</hibernate-mapping>

DAO

public class BillDAO {

    public int insert(BillDetails obj) {
        Session session = HibernateUtil.getSessionFactory().openSession();
        session.beginTransaction();
        session.save(obj);
        session.getTransaction().commit();
        return 1;
    }

例外：

  Exception in thread "main" org.hibernate.id.IdentifierGenerationException: null id generated for:class iland.hbm.BillProductDetails
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:123)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.performSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:117)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
    at org.hibernate.impl.SessionImpl.fireSaveOrUpdate(SessionImpl.java:685)
    at org.hibernate.impl.SessionImpl.saveOrUpdate(SessionImpl.java:677)
    at org.hibernate.engine.CascadingAction$5.cascade(CascadingAction.java:252)
    at org.hibernate.engine.Cascade.cascadeToOne(Cascade.java:392)
    at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:335)
    at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:204)
    at org.hibernate.engine.Cascade.cascadeCollectionElements(Cascade.java:425)
    at org.hibernate.engine.Cascade.cascadeCollection(Cascade.java:362)
    at org.hibernate.engine.Cascade.cascadeAssociation(Cascade.java:338)
    at org.hibernate.engine.Cascade.cascadeProperty(Cascade.java:204)
    at org.hibernate.engine.Cascade.cascade(Cascade.java:161)
    at org.hibernate.event.def.AbstractSaveEventListener.cascadeAfterSave(AbstractSaveEventListener.java:475)
    at org.hibernate.event.def.AbstractSaveEventListener.performSaveOrReplicate(AbstractSaveEventListener.java:353)
    at org.hibernate.event.def.AbstractSaveEventListener.performSave(AbstractSaveEventListener.java:203)
    at org.hibernate.event.def.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:129)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:210)
    at org.hibernate.event.def.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:56)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:195)
    at org.hibernate.event.def.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:50)
    at org.hibernate.event.def.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:93)
    at org.hibernate.impl.SessionImpl.fireSave(SessionImpl.java:713)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:701)
    at org.hibernate.impl.SessionImpl.save(SessionImpl.java:697)
    at iland.bill.BillDAO.insert(BillDAO.java:30)
    at iland.bill.BillNewAction.main(BillNewAction.java:76)

如何解决此问题。

编辑：我的BillDetails Pojo

public class BillDetails implements java.io.Serializable {

    private Long billNo;
    private CustomerDetails customerDetails;
    private Client client;
    private BigDecimal subTotal;
    private BigDecimal vat;
    private BigDecimal total;
    private String paymentType;
    private String status;
    private Timestamp addDate;
    private Set billPaidDetailses = new HashSet(0);
    private List<BillProductDetails> billProductList = new ArrayList<BillProductDetails>();
    //getter setter

}

 public class BillProductDetails  implements java.io.Serializable {

 private BillProductDetailsId id;
 private Client client;
 private BillDetails billDetails;
 private ProductDetails productDetails;
 private long qty;
 private BigDecimal unitPrice;
 private BigDecimal sellingPrice;
 private Integer discountPercent;
 //getter and setter
}

 public class BillProductDetailsId  implements java.io.Serializable {
 private long productId;
 private long billNo;
 //getter and setter
 }

Answer 1

你需要：

session.close();

在insert（）方法的末尾。

确保将Cascade.ALL设置为：

billDetails.billProductList
billProductDetails.productDetails
billProductDetails.billDetails

确保所有id都有@Id和@GeneratedValue设置

@Id @GeneratedValue
Integer getId() { ... };

您的映射有：

<bag name="billProductList" table="bill_product_details" inverse="true" lazy="false" fetch="join" cascade="all">
        <key>
            <column name="bill_no" not-null="true" />
        </key>
        <one-to-many class="iland.hbm.BillProductDetails" />
</bag>

<many-to-one name="billDetails" class="iland.hbm.BillDetails" update="false" insert="false" fetch="select">
        <column name="bill_no" not-null="true" />
</many-to-one>

所以，如果你选择你的包是“反向的”，你需要让多对一方控制这种关联。因此，您需要删除：

update =“false”
插入件= “假”

来自

您也可以控制一对多，这意味着删除“反向”属性，但这是不可取的，因为每当您更改列表时它将始终删除/重新插入内容。

这样，这一端就能控制关联。

线程＆＃34; main＆＃34;中的例外情况org.hibernate.id.IdentifierGenerationException：为以下内容生成的null id：class iland.hbm.BillProductDetails

1 个答案: