Hibernate - 我如何持久化一个对象？

Question

所以我制作了一个简单的休眠应用程序，并使用 HibernateUtil 静态方法启动了一个提供适当会话的 SessionFactory。

问题是 - 我怎样才能坚持使用此代码？而且我对如何从这个设计中构建以结合 HibernateUtil 来满足我的每个对象需求感到更加困惑？

package com.hibernation.main;

import com.hibernation.model.Animal;
import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
import org.hibernate.cfg.Configuration;
import org.hibernate.service.ServiceRegistry;


/**
 * Created by jonathan on 27/12/16.
 */
public class Earth {

    public static void main(String[] args){

        Animal a = new Animal(1,"lizard", "gekko", "test");

        HibernateUtil();
    }

    public static void HibernateUtil(){

        // create configuration instance and pass in the
        // hibernate configuration file.
        Configuration configuration = new Configuration();
        configuration.configure("hibernate.cfg.xml");

        // version 4.x and up, service registry is being used.
        // The ServiceRegistry scopes the Service.
        // The ServiceRegistry manages the lifecycle of the Service.
        // The ServiceRegistry handles injecting dependencies into the Service
        // (actually both a pull and a push/injection approach are supported).
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();

        // create a Session factory instance: session factory creates sessions
        // at the request of clients.
        // conceptually, this is a single data store that is thread safe.
        // should be wrapped in a singleton (HibernateUtil being a common convention)
        // the internal state is immutable - once it is created the state is set.
        SessionFactory factory = configuration.buildSessionFactory(serviceRegistry);

        // get the current session.
        Session session = factory.getCurrentSession();

        // begin transaction
        session.getTransaction().begin();

        // Print out all required information
        System.out.println("Session Is Opened :: "+ session.isOpen());
        System.out.println("Session Is Connected :: "+ session.isConnected());



        // commit transaction
        session.getTransaction().commit();




    }



}

Answer 1

问题是 - 我怎样才能坚持使用此代码？

不能，必须修改代码。

您必须像这样保存实体：

/**
 * Created by jonathan on 27/12/16.
 */
public class Earth {

    public static void main(String[] args){

        Animal a = new Animal(1,"lizard", "gekko", "test");

        HibernateUtil(a);
    }

    public static void HibernateUtil(Animal a){

        // create configuration instance and pass in the
        // hibernate configuration file.
        Configuration configuration = new Configuration();
        configuration.configure("hibernate.cfg.xml");

        // version 4.x and up, service registry is being used.
        // The ServiceRegistry scopes the Service.
        // The ServiceRegistry manages the lifecycle of the Service.
        // The ServiceRegistry handles injecting dependencies into the Service
        // (actually both a pull and a push/injection approach are supported).
        ServiceRegistry serviceRegistry = new StandardServiceRegistryBuilder().applySettings(configuration.getProperties()).build();

        // create a Session factory instance: session factory creates sessions
        // at the request of clients.
        // conceptually, this is a single data store that is thread safe.
        // should be wrapped in a singleton (HibernateUtil being a common convention)
        // the internal state is immutable - once it is created the state is set.
        SessionFactory factory = configuration.buildSessionFactory(serviceRegistry);

        // get the current session.
        Session session = factory.getCurrentSession();

        // begin transaction
        session.getTransaction().begin();

        // Print out all required information
        System.out.println("Session Is Opened :: "+ session.isOpen());
        System.out.println("Session Is Connected :: "+ session.isConnected());
        session.save(a);


        // commit transaction
        session.getTransaction().commit();




    }



}

小心

这是一个糟糕的例子，因为它是very procedual，而不是面向对象的，并且只包含对代码的最小更改。还有许多其他问题需要解决，比如无法访问已构建的 sessionfactory，请阅读OOD。

IoC 和得墨忒耳定律迫使我们使用 TransactionManager。 Spring-TX 是通常的 State-of-the-art 实现。