方法Hibernate.createBlob()从Hibernate 4.0.1中弃用，并移至Hibernate.getLobCreator(Session session).createBlob() [英] Method Hibernate.createBlob() is deprecated from Hibernate 4.0.1 and moved to Hibernate.getLobCreator(Session session).createBlob()

问题描述

方法Hibernate.createBlob()，并将其移至了Hibernate.getLobCreator(Session session).createBlob().任何解决方案都应在方法getLobCreator(Session session)中传递什么，即代替Session，或者其他解决方案，展示如何使用Spring和Hibernate将图像检索并保存到DB中.

Method Hibernate.createBlob() is deprecated from Hibernate 4.0.1 and moved to Hibernate.getLobCreator(Session session).createBlob(). Any solution what should I pass inside method getLobCreator(Session session), i.e in place of Session, Or any other solution showing how to retrieve and save an image into DB using Spring and Hibernate.

推荐答案

根据此简单教程，

会话对象

会话用于获得与数据库的物理连接. Session对象是轻量级的，旨在 每次需要与数据库进行交互时都实例化. 永久对象通过会话对象保存和检索.

Session Object

A Session is used to get a physical connection with a database. The Session object is lightweight and designed to be instantiated each time an interaction is needed with the database. Persistent objects are saved and retrieved through a Session object.

会话对象不应长时间保持打开状态，因为 它们通常不是线程安全的，应该创建它们并 根据需要销毁了它们.

The session objects should not be kept open for a long time because they are not usually thread safe and they should be created and destroyed them as needed.

在Hibernate 4.0+中，您可以从SessionFactory获取Session对象.让我们为此任务编写一个方便的类.

In Hibernate 4.0+ you can get Session object from a SessionFactory. Let's write a handy class for this task.

package your.company.util;

import org.hibernate.SessionFactory;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;
import org.hibernate.service.ServiceRegistryBuilder;

public class HibernateUtil {

    private static final SessionFactory sessionFactory;
    static {
        try {
            // Create the SessionFactory from hibernate.cfg.xml
            Configuration configuration = new Configuration().configure();
            ServiceRegistry registry = new ServiceRegistryBuilder()
                    .applySettings(configuration.getProperties())
                    .buildServiceRegistry();
            sessionFactory = configuration.buildSessionFactory(registry);
        } catch (Throwable ex) {
            // Make sure you log the exception, as it might be swallowed
            System.err.println("Initial SessionFactory creation failed." + ex);
            throw new ExceptionInInitializerError(ex);
        }
    }

    public static SessionFactory getSessionFactory() {
        return sessionFactory;
    }

    public static void shutdown() {
        // Close caches and connection pools
        getSessionFactory().close();
    }

}

然后:

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

byte[] bFile = /* load image into byte array */;
Blob image = Hibernate.getLobCreator(session).createBlob(bFile);
/* ? Your actions with Blob ? */

session.getTransaction().commit();

如果有效，请通知我.

Let me know, if it works.

或(假设Employee是具有字段@Lob private byte[] photo;的POJO，绑定到相应的表):

Or (assume Employee is a POJO with a field @Lob private byte[] photo;, binded to the corresponding table):

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

byte[] bFile = /* load image into byte array */;
Employee employee = new Employee();
employee.setPhoto(bFile);

session.save(employee);

session.getTransaction().commit();

来自 mkyong.com 的信息.在这里，您可以找到有关如何将图像保存到数据库的完整示例.还有如何检索图像的示例.

Info from mkyong.com. Here you can find the full example of how to save image into database. And the example of how to retrieve image.

注意:对于Hibernate 4.3及更高版本，您在try块中的代码会稍有变化.因为类ServiceRegistryBuilder被StandardServiceRegistryBuilder代替.

Note: For Hibernate 4.3+ your code inside try block slightly changes. Because class ServiceRegistryBuilder is replaced by StandardServiceRegistryBuilder.

Configuration configuration = new Configuration().configure();
StandardServiceRegistryBuilder builder = new StandardServiceRegistryBuilder()
        .applySettings(configuration.getProperties());
SessionFactory factory = configuration.buildSessionFactory(builder.build());

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