休眠调用需要一分钟以上

Question

我有一个非常小的数据库，有 5 个表和 2 个记录 在我进行数据库更改并在 Eclipse 中运行“休眠代码生成”以自动生成休眠文件之前，一切都运行良好 现在，当我调用使用休眠 5 的 Web 服务时，执行此记录需要超过 2 分钟

this.sessionFactory = this.configuration.buildSessionFactory(this.sr);

更新： 我忘了说如果我把战争放在一个tomcat服务器上（不是我的eclipse），它需要几秒钟

这是完整的代码

Configuration configuration;
ServiceRegistry sr;
SessionFactory sessionFactory;

在init方法中

this.configuration = new Configuration().configure();
configuration.addClass(Surveys.class);
configuration.addClass(MembersAnswers.class);
configuration.addClass(Categories.class);
configuration.addClass(PossibleAnswers.class);
configuration.addClass(Questions.class);
configuration.addClass(CategoriesAnswers.class);
this.sr = new StandardServiceRegistryBuilder().applySettings( 
this.configuration.getProperties()).build();
this.sessionFactory = this.configuration.buildSessionFactory(this.sr);

这是我的配置文件

<session-factory>
    <property name="hibernate.bytecode.use_reflection_optimizer">false</property>
    <property name="hibernate.connection.driver_class">org.postgresql.Driver</property>
    <property name="hibernate.connection.password">password</property>
    <property name="hibernate.connection.url">jdbc:postgresql://xxxxxxxxx/yyy</property>
    <property name="hibernate.connection.username">user</property>
    <property name="hibernate.dialect">org.hibernate.dialect.PostgreSQLDialect</property>
    <property name="hibernate.enable_lazy_load_no_trans">true</property>
    <property name="hibernate.search.autoregister_listeners">true</property>
    <property name="hibernate.validator.apply_to_ddl">false</property>
    <mapping class="DBFiles.MembersAnswers"/>
    <mapping class="DBFiles.PossibleAnswers"/>
    <mapping class="DBFiles.CategoriesAnswers"/>
    <mapping class="DBFiles.Questions"/>
    <mapping class="DBFiles.Categories"/>
    <mapping class="DBFiles.Surveys"/>
</session-factory>

这是自动生成的文件之一的示例

@Entity
@Table(name = "categories", schema = "edi_ms")
public class Categories implements java.io.Serializable {

private long categoryId;
private String categoryName;
private Date effectiveDate;
private Date expirationDate;
private Set<CategoriesAnswers> categoriesAnswerses = new HashSet<CategoriesAnswers>(0);

public Categories() {
}

public Categories(long categoryId, String categoryName, Date effectiveDate) {
    this.categoryId = categoryId;
    this.categoryName = categoryName;
    this.effectiveDate = effectiveDate;
}

public Categories(long categoryId, String categoryName, Date effectiveDate, Date expirationDate,
        Set<CategoriesAnswers> categoriesAnswerses) {
    this.categoryId = categoryId;
    this.categoryName = categoryName;
    this.effectiveDate = effectiveDate;
    this.expirationDate = expirationDate;
    this.categoriesAnswerses = categoriesAnswerses;
}

@Id

@Column(name = "category_id", unique = true, nullable = false)
public long getCategoryId() {
    return this.categoryId;
}

public void setCategoryId(long categoryId) {
    this.categoryId = categoryId;
}

@Column(name = "category_name", nullable = false, length = 20)
public String getCategoryName() {
    return this.categoryName;
}

public void setCategoryName(String categoryName) {
    this.categoryName = categoryName;
}

@Temporal(TemporalType.DATE)
@Column(name = "effective_date", nullable = false, length = 13)
public Date getEffectiveDate() {
    return this.effectiveDate;
}

public void setEffectiveDate(Date effectiveDate) {
    this.effectiveDate = effectiveDate;
}

@Temporal(TemporalType.DATE)
@Column(name = "expiration_date", length = 13)
public Date getExpirationDate() {
    return this.expirationDate;
}

public void setExpirationDate(Date expirationDate) {
    this.expirationDate = expirationDate;
}

@OneToMany(fetch = FetchType.LAZY, mappedBy = "categories")
public Set<CategoriesAnswers> getCategoriesAnswerses() {
    return this.categoriesAnswerses;
}

public void setCategoriesAnswerses(Set<CategoriesAnswers> categoriesAnswerses) {
    this.categoriesAnswerses = categoriesAnswerses;
}

Answer 1

首先查看SessionFactory 内部发生的情况。 Hibernate 提供了一个 JMX 连接器，请参阅documentation here。

如果启用hibernate.generate_statistics 配置属性，Hibernate 将 通过SessionFactory.getStatistics() 公开一些指标。 Hibernate 甚至可以 配置为通过 JMX 公开这些统计信息。 这样，您可以访问包含各种类型的 Statistics 类 二级缓存指标。

然后您可以开始研究您的热点以及如何重构它们。您确实需要从收集更多指标开始。现在它可能是任何事情，包括 GC 问题。

或者
似乎SessionFactory 被创建了好几次。您需要确保 SessionFactory 被创建一次。

public class HibernateUtil {
  // Private constructor; Class cannot be initialized
  private HibernateUtil() {}

  private static final SessionFactory sessionFactory;
  // create sessionFactory only once   
  static {
    // A SessionFactory is set up once for an application!
    final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
        .configure() // configures settings from hibernate.cfg.xml
        .build();
    try {
      sessionFactory = new MetadataSources(registry).buildMetadata().buildSessionFactory();
    } catch (Exception e) {
      // The registry would be destroyed by the SessionFactory, but we had trouble building
      // the SessionFactory so destroy it manually.
      StandardServiceRegistryBuilder.destroy( registry );
    }
  }

  public static SessionFactory getSessionFactory() {
    return sessionFactory;
  }
}

现在您可以在代码中调用初始化的SessionFactory：

Session session = HibernateUtil.getSessionFactory().openSession();

这样，Hibernate 已经在容器启动时初始化了。希望这会有所帮助。

Answer 2

我们认为问题在于，由于服务器靠近数据库，因此工作正常 还在靠近数据库的 PC 上工作

为了解决我添加的问题

<property name="hibernate.temp.use_jdbc_metadata_defaults">false</property>

到 hibernate.cfg.xml 以防止休眠进入数据库并验证结构。

这解决了我的问题