为什么休眠什么都不做

Question

>我已经用Hibernate 3建立了一个Spring项目，我正在使用注释。我刚刚实现了一个导入脚本，该脚本填充一个对象并使用我从HibernateSessionFactory.getSession()调用中获得的会话对象进行保存。

我的配置看起来像这样(名称和详细信息已更改以保护无辜者等(

<?xml version='1.0' encoding='UTF-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
      "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
      "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
<!-- Generated by MyEclipse Hibernate Tools.                   -->
<hibernate-configuration>
<session-factory>
    <property name="hbm2ddl.auto">update</property>
    <property name="dialect">
        org.hibernate.dialect.PostgreSQLDialect
    </property>
    <property name="connection.url">
    jdbc:postgresql://localhost:5432/foobar
    </property>
    <property name="connection.username">myuser</property>
    <property name="connection.password">mypass</property>
    <property name="connection.driver_class">
        org.postgresql.Driver
    </property>
    <property name="myeclipse.connection.profile">
        org.postgres.Driver
    </property>
    <mapping class="com.mycompany.Foo" />
    <mapping class="com.mycompany.Bar" />
</session-factory>
</hibernate-configuration>

据我了解，hbm2ddl.auto=update 配置应该意味着我的表将自动创建。

我的HibernateSessionFactory看起来像这样：

package com.mycompany;
import org.hibernate.HibernateException;
import org.hibernate.Session;
import org.hibernate.cfg.Configuration;
import org.hibernate.cfg.AnnotationConfiguration;
/**
 * Configures and provides access to Hibernate sessions, tied to the
 * current thread of execution.  Follows the Thread Local Session
 * pattern, see {@link http://hibernate.org/42.html }.
 */
public class HibernateSessionFactory {
    /** 
     * Location of hibernate.cfg.xml file.
     * Location should be on the classpath as Hibernate uses  
     * #resourceAsStream style lookup for its configuration file. 
     * The default classpath location of the hibernate config file is 
     * in the default package. Use #setConfigFile() to update 
     * the location of the configuration file for the current session.   
     */
    private static String CONFIG_FILE_LOCATION = "/hibernate.cfg.xml";
    private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
    private static Configuration configuration = new AnnotationConfiguration();    
    private static org.hibernate.SessionFactory sessionFactory;
    private static String configFile = CONFIG_FILE_LOCATION;
    static {
        try {
            configuration.configure(configFile);
            sessionFactory = configuration.buildSessionFactory();
        } catch (Exception e) {
            System.err.println("%%%% Error Creating SessionFactory %%%%");
            e.printStackTrace();
        }
    }
    private HibernateSessionFactory() {
    }
    /**
     * Returns the ThreadLocal Session instance.  Lazy initialize
     * the <code>SessionFactory</code> if needed.
     *
     *  @return Session
     *  @throws HibernateException
     */
    public static Session getSession() throws HibernateException {
        Session session = (Session) threadLocal.get();
        if (session == null || !session.isOpen()) {
            if (sessionFactory == null) {
                rebuildSessionFactory();
            }
            session = (sessionFactory != null) ? sessionFactory.openSession() : null;
            threadLocal.set(session);
        }
        return session;
    }
    /**
     *  Rebuild hibernate session factory
     *
     */
    public static void rebuildSessionFactory() {
        try {
            configuration.configure(configFile);
            sessionFactory = configuration.buildSessionFactory();
        } catch (Exception e) {
            System.err.println("%%%% Error Creating SessionFactory %%%%");
            e.printStackTrace();
        }
    }
    /**
     *  Close the single hibernate session instance.
     *
     *  @throws HibernateException
     */
    public static void closeSession() throws HibernateException {
        Session session = (Session) threadLocal.get();
        threadLocal.set(null);
        if (session != null) {
            session.close();
        }
    }
    /**
     *  return session factory
     *
     */
    public static org.hibernate.SessionFactory getSessionFactory() {
        return sessionFactory;
    }
    /**
     *  return session factory
     *
     *  session factory will be rebuilded in the next call
     */
    public static void setConfigFile(String configFile) {
        HibernateSessionFactory.configFile = configFile;
        sessionFactory = null;
    }
    /**
     *  return hibernate configuration
     *
     */
    public static Configuration getConfiguration() {
        return configuration;
    }
}

我很确定我正确使用了这段代码，基本上我的代码逻辑遵循：

Session session = HibernateSessionFactory.getSession();
Foo foo = new Foo();
...
session.save(foo);

所以这应该要么保存我的对象，要么开始大喊大叫，因为我做错了什么愚蠢的事情。什么也没发生。

日志中没有输出，表仍然不存在，我已经手动并通过直接使用配置的 Eclipse 插件测试了连接。即使是save()调用也没有效果或错误。

这是配置错误还是逻辑错误？干杯。

Answer 1

您至少遇到以下问题：您不启动和提交任何事务。阅读 http://docs.jboss.org/hibernate/core/3.6/reference/en-US/html_single/#transactions-demarcation-nonmanaged，了解有关如何处理Hibernate事务的详细信息。

请注意，由于您使用的是 Spring，因此您绝对应该使用它的 Hibernate 支持，这将完全避免对这个 HibernateSessionFactory 类的需求，并允许您以声明方式而不是以编程方式划分事务。不要重新发明轮子，阅读 http://static.springsource.org/spring/docs/3.1.x/spring-framework-reference/htmlsingle/spring-framework-reference.html#orm-hibernate。