java - sessionfactory创建第一次需要花费大量时间加载

Question

我正在使用 hibernate 进行 Maven 应用程序开发。

首次加载应用程序时， session 工厂需要花费大量时间来加载(大约 3-4 分钟)，但后续 session 工厂的创建会立即发生。有人可以帮助我找出应该做出哪些改变来减少时间延迟吗？

这是 hibernate 实用程序文件:

package com.infosys.common.util;

import java.util.logging.Logger;

import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;

/*import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;*/

// TODO: Auto-generated Javadoc
/**
* The Class HibernateUtilities.
*/
public class HibernateUtilities {

    /** The Constant CONFIGURATION_LOCATION. */
    private static final String CONFIGURATION_LOCATION = "com/infosys/common/util/hibernate.cfg.xml";
    private static final Logger LOGGER = Logger.getLogger(HibernateUtilities.class.getName());

    /** The session factory. */
    private static SessionFactory sessionFactory = null;

    /** The service registry. */
    private static ServiceRegistry serviceRegistry;

    /**
     * Gets the session factory.
     *
     * @return the session factory
     */
    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    /**
     * Creates the session factory.
     *
     * @return the session factory
     * @throws Exception
     *             the exception
     */
    public synchronized static SessionFactory createSessionFactory() throws Exception {
        if (sessionFactory == null)
        {
            try {
                LOGGER.info("Logger Name: " + LOGGER.getName());

                // Step1 : Loading the configuration details from
                // hibernate.cfg.xml

                Configuration configuration = new Configuration().configure(CONFIGURATION_LOCATION);
                configuration.
           setProperty("hibernate.temp.use_jdbc_metadata_defaults","false");

                // Step2 : Creating ServiceRegistry using the
                // StandardServiceRegistryBuilder and Configuration defined in
                // Step 1
                serviceRegistry = new StandardServiceRegistryBuilder().configure(CONFIGURATION_LOCATION).build();

                // Step3 : Creating the SessionFactory using the Configuration
                // and serviceRegistry.
                sessionFactory = configuration.buildSessionFactory(serviceRegistry);

            } catch (Exception e) {
                throw e;
            }
        }
        return sessionFactory;
    }

    /**
     * Close session factory.
     */
    public static void closeSessionFactory()
    {
        if(sessionFactory!=null)
        {
            sessionFactory.close();
        }
    }
}

Answer 1

这很正常。 第一次配置 hibernate 并使用 session 工厂时(即当您运行程序时)，它需要读取您的 hibernate 配置、所有 POJO 文件和映射文件，确保您的映射、POJO 和数据库匹配等。 所以第一次运行总是需要时间