这是我的 hibernate 映射:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="Entities.Product" table="products">
        <id column="name" name="name" type="java.lang.String">
            <generator class="increment"/>
        </id>
        <property column="cost" name="cost" type="java.lang.Integer"/>
    </class>
</hibernate-mapping>

该表由两列组成:name VARCHAR(20), cost Integer。

Controller :

@Controller
public class ProductController {

    @RequestMapping("/products.htm")
    public String getAllProducts() throws SQLException
    {
        ProductDAOImpl mapping = new ProductDAOImpl();
        Product p = new Product();
        p.setCost(1000);
        p.setName("Саморезы");
        mapping.addProduct(p);
        return "index";
    }     
}

添加产品方法:

public void addProduct(Product product) throws SQLException {
        Session session = Hibernate.util.HibernateUtil.getSessionFactory().openSession();
        session.beginTransaction();
        session.save(product);
        session.getTransaction().commit();
        session.close();
    }

当我尝试运行它时出现异常:

org.hibernate.id.IdentifierGenerationException: Unknown integral data type for ids : java.lang.String
    org.hibernate.id.IdentifierGeneratorHelper.getIntegralDataTypeHolder(IdentifierGeneratorHelper.java:215)
    org.hibernate.id.IncrementGenerator.initializePreviousValueHolder(IncrementGenerator.java:123)
    org.hibernate.id.IncrementGenerator.generate(IncrementGenerator.java:69)
    org.hibernate.event.internal.AbstractSaveEventListener.saveWithGeneratedId(AbstractSaveEventListener.java:117)
    org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.saveWithGeneratedOrRequestedId(DefaultSaveOrUpdateEventListener.java:206)
    org.hibernate.event.internal.DefaultSaveEventListener.saveWithGeneratedOrRequestedId(DefaultSaveEventListener.java:55)
    org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.entityIsTransient(DefaultSaveOrUpdateEventListener.java:191)
    org.hibernate.event.internal.DefaultSaveEventListener.performSaveOrUpdate(DefaultSaveEventListener.java:49)
    org.hibernate.event.internal.DefaultSaveOrUpdateEventListener.onSaveOrUpdate(DefaultSaveOrUpdateEventListener.java:90)
    org.hibernate.internal.SessionImpl.fireSave(SessionImpl.java:764)
    org.hibernate.internal.SessionImpl.save(SessionImpl.java:756)
    org.hibernate.internal.SessionImpl.save(SessionImpl.java:752)
    DAOImpl.ProductDAOImpl.addProduct(ProductDAOImpl.java:26)
    Controllers.ProductController.getAllProducts(ProductController.java:20)
    sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
    sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    java.lang.reflect.Method.invoke(Method.java:606)
    org.springframework.web.bind.annotation.support.HandlerMethodInvoker.invokeHandlerMethod(HandlerMethodInvoker.java:175)
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.invokeHandlerMethod(AnnotationMethodHandlerAdapter.java:446)
    org.springframework.web.servlet.mvc.annotation.AnnotationMethodHandlerAdapter.handle(AnnotationMethodHandlerAdapter.java:434)
    org.springframework.web.servlet.DispatcherServlet.doDispatch(DispatcherServlet.java:945)
    org.springframework.web.servlet.DispatcherServlet.doService(DispatcherServlet.java:876)
    org.springframework.web.servlet.FrameworkServlet.processRequest(FrameworkServlet.java:961)
    org.springframework.web.servlet.FrameworkServlet.doGet(FrameworkServlet.java:852)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:620)
    org.springframework.web.servlet.FrameworkServlet.service(FrameworkServlet.java:837)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:727)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

如何解决？

最佳答案

您已将 ID 添加为 <generator class="increment"/>那么它必须是整数 在 <id column="name" name="name" type="integer"> 处使用整数而不是字符串,修改hibernate映射文件如下图

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN" "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
<hibernate-mapping>
    <class name="Entities.Product" table="products">
        <id column="name" name="name" type="integer">
            <generator class="increment"/>
        </id>
        <property column="cost" name="cost" type="java.lang.Integer"/>
    </class>
</hibernate-mapping>

关于java - ids : java. lang.String 的未知整数数据类型，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/24755500/