java - Tomcat + hibernate = 找不到查询类的持久类

Question

我正在开发一个网络应用程序并将其部署在 Tomcat 7.0 上。我的应用程序使用 MySQL 数据库。我已经配置了应用程序和数据库之间的连接，并希望添加对 Hibernate 5.2.5 的支持。我可以使用下面的配置通过 Hibernate 控制台与数据库通信，并且当我在非网络应用程序中使用它时它可以工作。问题仅出现在我将其部署在服务器上时。我收到警告

no persistent classes found for query class: from entities.UserH

然后由它引起的500服务器错误。

我的实体类:

@Entity
@Table(name = "users", uniqueConstraints = {@UniqueConstraint(columnNames =     {"id"})})
public class UserH {

    @Id
    @GeneratedValue(strategy = GenerationType.IDENTITY)
    @Column(name = "id", nullable = false, unique = true, length = 11)
    private int id;
    @Column(name = "login", nullable = false, length = 45)
    private String login;
    @Column(name = "name", nullable = false, length = 45)
    private String name;
    @Column(name = "surname", nullable = false, length = 45)
    private String surname;

    /* getters and setters*/
}

我的 hibernate-annotation.cfg.xml:

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE hibernate-configuration PUBLIC
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    "http://hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!-- Database connection properties - Driver, URL, user, password -->
        <property name="hibernate.connection.driver_class">com.mysql.jdbc.Driver</property>
        <property name="hibernate.connection.url">jdbc:mysql://localhost:3306/web-database</property>
        <property name="hibernate.connection.username">username</property>
        <property name="hibernate.connection.password">password</property>

        <!-- org.hibernate.HibernateException: No CurrentSessionContext configured! -->
        <property name="hibernate.current_session_context_class">thread</property>

        <!-- Mapping with model class containing annotations -->
        <mapping class="entities.UserH"/>
    </session-factory>
</hibernate-configuration>

获取用户的方法:

public List<UserH> getAllUsers() {

    try (Session session = HibernateUtils.getSessionAnnotationFactory().getCurrentSession()) {
        session.beginTransaction();
        Query<UserH> usersQuery = session.createQuery("from entities.UserH", UserH.class);
        List<UserH> usersList = usersQuery.getResultList();

        session.getTransaction().commit();

        return usersList;
    }
}

正如我提到的 - 它适用于普通应用程序，但不适用于 Tomcat。我将所有可用元素添加到 Web 工件中，但没有帮助。我什至尝试使用 persistance.xml 添加 JPA 支持，但仍然没有成功。

还有什么问题？

编辑:我的 HibernateUtils 类:

public class HibernateUtils {
    private static SessionFactory sessionAnnotationFactory;

    private static SessionFactory buildSessionAnnotationFactory() {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            Configuration configuration = new Configuration();
            configuration.configure("hibernate-annotation.cfg.xml");
            System.out.println("Hibernate Annotation Configuration loaded");

            ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();
            System.out.println("Hibernate Annotation serviceRegistry created");

            SessionFactory sessionFactory = configuration.buildSessionFactory(serviceRegistry);

            return sessionFactory;
        } catch (Throwable ex) {
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionAnnotationFactory() {
        if (sessionAnnotationFactory == null) 
            sessionAnnotationFactory = buildSessionAnnotationFactory();
        return sessionAnnotationFactory;
    }
}

Answer 1

也许这不是我问题的正确答案，但这确实对我有用。我用 JPA 配置 + hibernate 替换了 hibernate。

所以我没有使用 hibernate-annotation.cfg.xml + Session，而是使用了 persistance.xml + EntityManager:

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0">

    <persistence-unit name="NewPersistenceUnit" transaction-type="RESOURCE_LOCAL">
        <provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>
        <class>entities.UserH</class>

        <properties>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/web-database"/>
            <property name="javax.persistence.jdbc.user" value="Admin"/>
            <property name="javax.persistence.jdbc.password" value="password2@"/>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
            <property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect"/>
            <property name="hibernate.hbm2ddl.auto" value="update"/>
        </properties>
    </persistence-unit>

</persistence>

获取实体管理器:

public static EntityManager getEntityManager() {
    EntityManager entityManager = Persistence
            .createEntityManagerFactory("NewPersistenceUnit")
            .createEntityManager();

    return entityManager;
}

获取所有用户:

public List<UserH> getAllUsers() {

    EntityManager entityManager = HibernateUtils.getEntityManager();
    EntityTransaction transaction = entityManager.getTransaction();
    transaction.begin();
    TypedQuery<UserH> usersQuery = entityManager.createQuery("from UserH ", UserH.class);
    List<UserH> usersList = usersQuery.getResultList();
    transaction.commit();
    entityManager.close();

    return usersList;
}

但是，我仍然不明白为什么这种配置有效而单独使用 hibernate 却不能。如有任何意见/建议，我们将不胜感激。