hibernate的配置 1

<?xml version="1.0" encoding="UTF-8"?>
    <!-- 展开jar包有个hibernate-mapping-3.0.dtd,拷贝这几行dtd -->
    <!DOCTYPE hibernate-mapping PUBLIC 
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
        <!-- 根节点叫做hibernate-mapping,package表示User所在的包名
            子节点的class,name属性写类名,package和name组成一个完全限定名
            所以不写package的时候name属性要写完全限定名,table写表名---->
    <hibernate-mapping package="com.kaishengit.pojo">
        
        <class name="User" table="user">
        <!-- pojo中的属性要对应表里面的列 -->
            <!-- id这个节点是主键列,name写属性的名字,column
                是表中列的名字,作为主键还要有生成策略
                    generator class="native"native表示自动增长-->
            <id name="id" column="id">
                <generator class="native"/>
            </id>
            <!-- 剩下普通列和属性的对应,当name和column相同的时候可以只
            写name-->
            <property name="username"/>
            <property name="password" column="password"/>
            
        </class>
    </hibernate-mapping>

    <?xml version="1.0" encoding="UTF-8"?>
    <!-- 打开jar包中的hibernate-configuration-3.0.dtd,复制这几行dtd -->
    <!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
    <hibernate-configuration>
        <!-- 这个session和http中的session没有关系  -->
        <!--\hibernate-release-4.1.1.Final\hibernate-release-4.1.1.Final\project\etc的hibernate.properties -->
        <session-factory>
            <!-- 以hibernate.开头的可以省略hibernate. -->
            <property name="connection.driver_class">com.mysql.jdbc.Driver</property>
            <property name="connection.url">jdbc:mysql:///hibernate</property>
            <property name="connection.username">root</property>
            <property name="connection.password">root</property>
            
            <!-- 方言(较好的移植性) -->
            <property name="dialect">org.hibernate.dialect.MySQLDialect</property>
            
            <!-- c3p0数据源(以前用的dbcp) 
                需要pom中导入这两个jar包
                <dependency>
                    <groupId>c3p0</groupId>
                    <artifactId>c3p0</artifactId>
                    <version>0.9.1</version>
                </dependency>
                <dependency>
                    <groupId>org.hibernate</groupId>
                    <artifactId>hibernate-c3p0</artifactId>
                    <version>4.2.0.Final</version>
                </dependency>-->
            <property name="c3p0.max_size">10</property>
            <property name="c3p0.min_size">2</property>
            <property name="c3p0.timeout">5000</property>
            <property name="c3p0.max_statements">100</property>
            <property name="c3p0.idle_test_period">3000</property>
            <property name="c3p0.acquire_increment">2</property>
            <property name="c3p0.validate">false</property>
            
            <!-- 执行的时候能看到sql语言 -->
            <property name="show_sql">true</property>
            <!-- 把session放到当前线程里 比如放在main方法中就是放在主线程里,使用的
            时候就可以获得session.-->
            <property name="current_session_context_class">thread</property>
            <!-- 表明映射文件的位置 -->
            <mapping resource="com/kaishengit/pojo/User.hbm.xml"/>
            
                
        </session-factory>
            
    </hibernate-configuration>

    //configure()才会去读取hibernate,cfg.xml  
    Configuration cfg = new Configuration().configure();
    ServiceRegistry serviceRegistry= new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();
    SessionFactory sessionFactory = cfg.buildSessionFactory(serviceRegistry);
    /* 最终是为了创建sessionfactory,这是4.0  3.0的hibernate只需要
        Configuration cfg = new Configuration().configure();
    SessionFactory sessionFactory = cfg.buildSessionFactory();*/
    Session session = sessionFactory.getCurrentSession();
    
    
    /* 增删改查都在事务中完成 session.beginTransaction();
    session.getTransaction().commit();或者
    session.getTransaction().rollback();*/
    session.beginTransaction();
    
    User user = new User();
    user.setUsername("jack");
    user.setPassword("123");
    
    session.save(user);
    
    session.getTransaction().commit();
/*或者Transaction tran = session.beginTransaction();
    tran.commit();*/
    
    

public class HibernateUtil {
    // 静态只读一次 
    private static SessionFactory factory = buildSessionFactory();

    private static SessionFactory buildSessionFactory() {
        Configuration cfg = new Configuration().configure();
        ServiceRegistry serviceRegistry= new ServiceRegistryBuilder().applySettings(cfg.getProperties()).buildServiceRegistry();
        return cfg.buildSessionFactory(serviceRegistry);
    }
    //提供获取sessionfactory方法
    public static SessionFactory getSessionFactory() {
        return factory;
    }
    // 提供获取session的方法 
    public static Session getSession() {
        return getSessionFactory().getCurrentSession();
    }
    
    
}

public class Test {

    public static void main(String[] args) {
//添加 
        User user = new User();
        user.setUsername("tom");
        user.setPassword("000000");
        
        Session session = HibernateUtil.getSession();
        session.beginTransaction();
        // 保存要放在事务中 
        session.save(user);
        session.getTransaction().commit();
        
        
        
        
// 查询 
        Session session = HibernateUtil.getSession();
        session.beginTransaction();
        // 要放在事务中 ,根据主键查询
        User user = (User) session.get(User.class, 1);
        System.out.println(user.getUsername());
        session.getTransaction().commit();
        
// 删除

        Session session = HibernateUtil.getSession();
        session.beginTransaction();
        // 要放在事务中 ,查出来才能删,会输出两条sql语句
        User user = (User) session.get(User.class, 2);
        session.delete(user);
        session.getTransaction().commit();



//修改 

        Session session = HibernateUtil.getSession();
        session.beginTransaction();
        // 要放在事务中 查出来才能修改
        User user = (User) session.get(User.class, 1);
        //只有当set的值跟以前不一样才回去执行update修改
        user.setUsername("jack");
        session.getTransaction().commit();


// 查询所有 
        Session session = HibernateUtil.getSession();
        String hql = "from User";// User是类名,不是表名,要切记 
        Query query = session.createQuery(hql);
        List<User> userList = query.list();
        for(User user : userList) {
            System.out.println(user.getUsername() + " : " + user.getPassword());
        }
        
        
        
        
        
        
    }
}