• hibernate.cfg.xml配置(Oracle+c3p0)


    说明:数据库:Oracle10g;连接池:c3p0

    结构:

    一、配置hibernate.cfg.xml

    <?xml version="1.0" encoding="UTF-8"?>
    
    <!DOCTYPE hibernate-configuration PUBLIC
    
    "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
    
    "http://hibernate.sourceforge.net/hibernate-configuration-3.0.dtd">
    
    <!-- c3p0连接池 -->
    <hibernate-configuration>
    
    <session-factory>
            <!-- 显示实际操作数据库时的SQL -->
            <property name="show_sql">true</property>
            <!-- SQL方言,这边设定的是Oracle -->
            <property name="dialect">org.hibernate.dialect.Oracle10gDialect</property>
            <!--驱动程序:Oracle数据库的配置 -->
            <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
            <!-- JDBC URL -->
            <property name="connection.url">jdbc:oracle:thin:@localhost:1521:myorcl</property>
            <!-- 数据库用户名 -->
            <property name="connection.username">scott</property>
            <!-- 数据库密码 -->
            <property name="connection.password">root</property>
            <!-- 指定连接池里最小连接数 -->
            <property name="hibernate.cp30.minsize">5</property>
            <!-- 指定连接池里的最大连接数 -->
            <property name="hibernate.c3p0.maxsize">20</property>
            <!-- 指定连接池里的超时时常 -->
            <property name="hibernate.cp30.timeout">1800</property>
            <!-- 指定连接池里最大缓存多少个Statement对象 -->
            <property name="hibernate.cp30.max_statements">50</property>
            <!-- 根据需要自动创建数据库表 -->
            <property name="hbm2ddl.auto">update</property>
            
            <!-- 对象与数据库表格映像文件 -->
           <mapping resource="com/chen/vo/News.hbm.xml"/>
    
        </session-factory>
    
    </hibernate-configuration>

    二、配置News.hbm.xml

    说明:由于连接的数据库是Oracle,所有这里指定了序列:seq_news,如果设置<generator class="native"/>,则在插入数据时Hibernate默认会去查找Oracle中的hibernate_sequence序列(默认序列)。

    <?xml version="1.0" encoding="utf-8"?>
    <!-- 指定Hibernate映射文件的DTD信息 -->
    <!DOCTYPE hibernate-mapping PUBLIC "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
    "http://hibernate.sourceforge.net/hibernate-mapping-3.0.dtd">
    <!-- hibernate-mapping是映射文件的根源素 -->
    <hibernate-mapping>
    <!-- 每个class对应一个持久化对象 -->
    <class name="com.chen.vo.News" table="news_table">
    <!-- id元素定义持久化类的标识属性 -->
    <id name="id">
    <generator class="sequence">
    <param name="sequence">seq_news</param>
    </generator>
    </id>
    <!-- property元素定义常规属性 -->
    <property name="title"/>
    <property name="content"/>
    </class>
    </hibernate-mapping>

    三、创建vo

    package com.chen.vo;
    
    public class News
    {
       //消息类的标识属性
       private Integer id;
       //消息标题
       private String title;
       //消息内容
       private String content;
       //id属性的setter和getter方法
       public void setId(Integer id)
       {
           this.id=id;
       }
       public Integer getId()
       {
           return this.id;
       }
       //title属性的setter和getter方法
       public void setTitle(String title)
       {
           this.title=title;
       }
       public String getTitle()
       { 
           return this.title; 
       }
       //content 属性的setter和getter方法
       public void setContent(String content)
       {
           this.content=content;
       }
       public String getContent()
       {
           return this.content;
       }
    }

    四、创建测试类

    package com.chen.vo;
    
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.Transaction;
    import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
    import org.hibernate.cfg.Configuration;
    import org.hibernate.service.ServiceRegistry;
    
    public class NewsManager {
        public static void main(String[] args) throws Exception
           {
              //实例化configuration
              Configuration conf =new Configuration().configure();
              //以Configuration创建SessionFactory.注:buildSessionFactory方法已过时,不过仍可以获取SessionFactory。
    //          SessionFactory sf=conf.buildSessionFactory();
              //采用ServiceRegistry获取SessionFactory
              StandardServiceRegistryBuilder serviceRegistryBuilder = new StandardServiceRegistryBuilder();  
              ServiceRegistry serviceRegistry = serviceRegistryBuilder.applySettings(conf.getProperties()).build(); 
              SessionFactory sf = conf.buildSessionFactory(serviceRegistry); 
              //创建session
              Session sess = sf.openSession(); 
              //开始事物 
              Transaction tx = sess.beginTransaction();
              //创建消息实例
              News n=new News();
              //设置消息标题和消息内容
              /**
               * Oracle插入数据说明:
               * 1.在News.hbm.xml中设置<generator class="native"/>
               * 连接Oracle,默认序列(Default.sequence)为hibernate_sequence
               * 使用native时Hibernate默认会去查找Oracle中的hibernate_sequence序列,所以插入数据时无需设置id。
               * 2.在News.hbm.xml中设置指定序列:
               * <generator class="sequence">
                    <param name="sequence">seq_news</param>
                 </generator>
               * Hibernate会按照序列seq_news创建新数据。
               */
              n.setTitle("title2");
              n.setContent("content2");
              //保存消息
              sess.save(n);
              //提交事务
              tx.commit();
              //关闭Session
              sess.close();
              sf.close();
           }
    
    }

    测试结果:

     

    五、创建junit测试类、HibernateSessionFactory,通过session实现增、删、查、改

    1.创建HibernateSessionFactory

    package com.chen.utils;
    import org.hibernate.HibernateException;
    import org.hibernate.Session;
    import org.hibernate.SessionFactory;
    import org.hibernate.boot.registry.StandardServiceRegistryBuilder;
    import org.hibernate.cfg.Configuration;
    import org.hibernate.service.ServiceRegistry;
    
    public class HibernateSessionFactory {
        private static final ThreadLocal<Session> threadLocal = new ThreadLocal<Session>();
        //private static String configfile = "/hibernate.cfg.xml";
        private static Configuration configuration = new Configuration().configure();
        private static SessionFactory sessionFactory;
    
        static {
            try {
                StandardServiceRegistryBuilder serviceRegistryBuilder = new StandardServiceRegistryBuilder();  
                ServiceRegistry serviceRegistry = serviceRegistryBuilder.applySettings(configuration.getProperties()).build(); 
                sessionFactory = configuration.buildSessionFactory(serviceRegistry); 
            } catch (HibernateException e) {
                e.printStackTrace();
            }
        }
    
        private HibernateSessionFactory() {
        }
    
        public static Session getSession() {
            Session session = (Session) threadLocal.get();
    
            if (session == null || !session.isOpen()) {
                session = (sessionFactory != null) ? sessionFactory.openSession()
                        : null;
                threadLocal.set(session);
            }
    
            return session;
        }
    
        public static void closeSesssion() {
            Session session = threadLocal.get();
            threadLocal.set(null);
            if (session != null) {
                session.close();
            }
        }
    
        public static SessionFactory getSessionFactory() {
            return sessionFactory;
        }
    
        public static void setSessionFactory(SessionFactory sessionFactory) {
            HibernateSessionFactory.sessionFactory = sessionFactory;
        }
    
        public static Configuration getConfiguration() {
            return configuration;
        }
    
        public static void setConfiguration(Configuration configuration) {
            HibernateSessionFactory.configuration = configuration;
        }
    }

     

    2.在测试类进行测试

    package com.chen.test;
    
    import java.util.List;
    
    import org.hibernate.Query;
    import org.hibernate.Session;
    import org.hibernate.Transaction;
    import org.junit.Test;
    
    import com.chen.utils.HibernateSessionFactory;
    import com.chen.vo.News;
    
    public class HibernateTest {
        //获取session
        @Test
        public void sessionTest(){
            Session session = HibernateSessionFactory.getSession();
            System.out.println(session);
        }
        //查询News的列表信息
        @Test
        public void listNews(){
            Session session = HibernateSessionFactory.getSession();
            Query query = session.createQuery("from News");
            List<?> list = query.list();
            System.out.println(list);
        }
        //通过id查询指定的News
        @Test
        public void findById(){
            Session session = HibernateSessionFactory.getSession();
            Query query = session.createQuery("from News where id=?");
            //设置参数
            query.setParameter(0, 1);
            //单值检索
            News n = (News) query.uniqueResult();
            System.out.println(n);
        }
        //添加News
        @Test
        public void saveNews(){
            Session session = HibernateSessionFactory.getSession();
            Transaction tx = session.beginTransaction();
            News n=new News();
            n.setTitle("title3");
            n.setContent("content3");
            session.saveOrUpdate(n);;
            tx.commit();
            session.close();
        }
        //修改News
        @Test
        public void updateNews(){
            Session session = HibernateSessionFactory.getSession();
            //先获取指定id的News
            Query query = session.createQuery("from News where id=?");
            query.setParameter(0, 5);
            News n = (News) query.uniqueResult();
            //再进行修改
            Transaction tx = session.beginTransaction();
            n.setContent("update_content5");
            session.saveOrUpdate(n);
            tx.commit();
            session.close();
            System.out.println(n);
        }
        //删除News
        @Test
        public void deteleNews(){
            Session session = HibernateSessionFactory.getSession();
            Query query = session.createQuery("from News where id=?");
            query.setParameter(0, 4);
            News n = (News) query.uniqueResult();
            Transaction tx = session.beginTransaction();
            session.delete(n);
            tx.commit();
            session.close();
        }
    
    }

    小结:“查”的实现是通过查询hql语句实现的。


    附:Oracle创建序列seq_news及相应的自动增长触发器

    create sequence seq_news;
    
    CREATE OR REPLACE TRIGGER "SCOTT"."trigger_news" 
       before insert on "SCOTT"."NEWS_TABLE"
       for each row
    begin
       if inserting then
          if :NEW."ID" is null then
             select seq_news.nextval into :NEW."ID" from dual;
          end if;
       end if;
    end;
    /
    ALTER TRIGGER "SCOTT"."trigger_news" ENABLE;

     

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  • 原文地址:https://www.cnblogs.com/wql025/p/4855849.html
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