Hibernate初識

小配置裏的代碼：

<?xml version='1.0'  encoding='utf-8'?>
<!DOCTYPE hibernate-mapping PUBLIC
        "-//Hibernate/Hibernate Mapping DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-mapping-3.0.dtd">
<hibernate-mapping package="cn.happy.entity">
    <class name="Dog" table="Dog" >
        <id name="dogid" column="dogid">
            <generator class="native"></generator>//id主鍵  自增
        </id>
        <property name="dogname" column="dogname"></property>
        <property name="dogage" column="dogage" ></property>
    </class>

</hibernate-mapping>

　　實體類：

/**
 * Created by lgy on 2017/9/18.
 */
public class Dog {
    private String dogname;
    private Integer dogage;
    private Integer dogid;

    public String getDogname() {
        return dogname;
    }

    public void setDogname(String dogname) {
        this.dogname = dogname;
    }

    public Integer getDogage() {
        return dogage;
    }

    public void setDogage(Integer dogage) {
        this.dogage = dogage;
    }

    public Integer getDogid() {
        return dogid;
    }

    public void setDogid(Integer dogid) {
        this.dogid = dogid;
    }
}

　　util：

public class HibernateUntil {
    private static Configuration cfg=new Configuration().configure();
    private static SessionFactory factory=cfg.buildSessionFactory();

    //1.方法返回session  靜態成員變量不能直接使用非靜態成員
    //Session依賴於Session工廠，工廠依賴於Configure
    public static Session getSession(){
        return factory.openSession();

    }
    //2.關閉session
    public static void closeSession(){
        getSession().close();
    

　　大配置：

<?xml version='1.0' encoding='utf-8'?>
<!DOCTYPE hibernate-configuration PUBLIC
        "-//Hibernate/Hibernate Configuration DTD 3.0//EN"
        "http://www.hibernate.org/dtd/hibernate-configuration-3.0.dtd">
<hibernate-configuration>
    <session-factory>
        <!--數據庫驅動-->
        <property name="connection.driver_class">oracle.jdbc.driver.OracleDriver</property>
        <!--數據庫url-->
        <property name="connection.url" >jdbc:oracle:thin:@localhost:1521:orcl</property>
        <!--數據庫username-->
        <property name="connection.username" >test</property>
        <!--數據庫password-->
        <property name="connection.password" >test</property>
        <!--hibernate方言--><!--和Spring整合時name屬性前S必須加hibernate，單獨用hibernate框架時，name屬性能夠直接用dialect-->
        <property name="hibernate.dialect" >org.hibernate.dialect.Oracle10gDialect</property>
        <!--輸出全部語句到控制檯-->
        <property name="hirbernate.show_sql" >true</property>
        <!--在log和console中打印出更新   格式化顯示sql-->
        <property name="hibernate.format_sql" >true</property>
        <!--hbm2ddl就是**.hbm.xml,生成特定數據庫的sql   從程序中自動建表 updata表示若是底層存在表，name更新表結構 -->
        <property name="hibernate.hbm2ddl.auto" >update</property>
        <!--指定當前session範圍和上下文  thread至當前線程用來跟蹤管理-->
        <property name="current_session_context_class" >thread</property>
        <mapping resource="cn/happy/entity/Dog.hbm.xml" ></mapping>
    </session-factory>
</hibernate-configuration>

　　Test測試類：

@Test
    public void testhibernate() {
        //configuration
        Configuration cfg=new Configuration().configure();
        SessionFactory factory=cfg.buildSessionFactory();
        Session session=factory.openSession();
        Transaction tx=session.beginTransaction();
        Dog dog=new Dog();
        dog.setDogname("小白");
        session.save(dog);
        tx.commit();
        System.out.println("add ok!");
        session.close();

    }

　　

//用get方法查詢數據庫
@Test
private void findStudent() {
    //02Hibernate 保存
    //讀取大配置文件，獲取鏈接的數據庫信息
    Configuration cfg=new Configuration().configure();
    //3建立SessionFactory
    SessionFactory factory=cfg.buildSessionFactory();
    //加工session
    Session session=factory.openSession();
    //開啓事務
    Transaction tx=session.beginTransaction();
    //5Hibernate
    //根據session的方法作數據操做  檢索
    Student student=session.get(Student.class,2);
    System.out.println(student.getName());
    //提交事務
    tx.commit();
    //關閉session
    session.close();
    System.out.println("success  ok");
}

//用load方法查詢
    @Test
    public void update2(){
        Configuration cfg=new Configuration().configure();
        SessionFactory factory=cfg.buildSessionFactory();
        Session session=factory.openSession();
        Transaction tx=session.beginTransaction();
        Dog dog=session.load(Dog.class,1);
        System.out.println("load-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=");
        System.out.println(dog.getDogname());
    }

　　load方法：

 

　　

 

 

不管get方法查詢，仍是load方法，都要開啓事務，也不要手動提交！！！