1.hibernate配置檔案

配置檔案示例

<hibernate-configuration><session-factory>
<!-- Database connection settings -->
<property name="connection.driver_class">org.h2.Driver</property>
<property name="connection.url">jdbc:h2:mem:db1;DB_CLOSE_DELAY=-1;MVCC=TRUE</property
 
>
<property name="connection.username">sa</property>
<property name="connection.password"/>
<!-- JDBC connection pool (use the built-in) -->
<property name="connection.pool_size">1</property>
<!-- SQL dialect -->
<property name="dialect">org.hibernate.dialect.H2Dialect</property
 
>
<!-- Disable the second-level cache  -->
<property name="cache.provider_class">org.hibernate.cache.internal.NoCacheProvider</property><!-- Echo all executed SQL to stdout -->
<property name="show_sql">true</property>
<!-- Drop and re-create the database schema on startup -->
 

<property name="hbm2ddl.auto">create</property>
<!-- Names the annotated entity class -->
<mapping class="org.hibernate.tutorial.annotations.Event"/></session-factory>
</hibernate-configuration>

對映檔案示例

<hibernate-mapping package="org.hibernate.tutorial.hbm">
    <class name="Event" table="EVENTS">
    <id name="id" column="EVENT_ID"><generator class="increment"/></id>
    <property name="date" type="timestamp" column="EVENT_DATE"/>
    <property name="title"/>
</hibernate-mapping>

1.1 類對映

<class name="Event" table="EVENTS">
    ...
</class>

1.2 id對映

<id name="id" column="EVENT_ID">
    ...
</id>

1.3 屬性對映

<property name="date" type="timestamp" column="EVENT_DATE"/>
<property name="title"/>

2. SessionFactory工作原理

org.hibernate.SessionFactory原始碼

package org.hibernate.tutorial.annotations;

import java.util.Date;
import java.util.List;

import org.hibernate.Session;
import org.hibernate.SessionFactory;
import org.hibernate.boot.MetadataSources;
import org.hibernate.boot.registry.StandardServiceRegistry;
import org.hibernate.boot.registry.StandardServiceRegistryBuilder;

import junit.framework.TestCase;

/**
 * Illustrates the use of Hibernate native APIs.  The code here is unchanged from the {@code basic} example, the
 * only difference being the use of annotations to supply the metadata instead of Hibernate mapping files.
 *
 * @author Steve Ebersole
 */
public class AnnotationsIllustrationTest extends TestCase {
    private SessionFactory sessionFactory;

    @Override
    protected void setUp() throws Exception {
        // A SessionFactory is set up once for an application!
        final StandardServiceRegistry registry = new StandardServiceRegistryBuilder()
                .configure() // configures settings from hibernate.cfg.xml
                .build();
        try {
            sessionFactory = new MetadataSources( registry ).buildMetadata().buildSessionFactory();
        }
        catch (Exception e) {
            // The registry would be destroyed by the SessionFactory, but we had trouble building the SessionFactory
            // so destroy it manually.
            StandardServiceRegistryBuilder.destroy( registry );
        }
    }

    @Override
    protected void tearDown() throws Exception {
        if ( sessionFactory != null ) {
            sessionFactory.close();
        }
    }

    @SuppressWarnings({ "unchecked" })
    public void testBasicUsage() {
        // create a couple of events...
        Session session = sessionFactory.openSession();
        session.beginTransaction();
        session.save( new Event( "Our very first event!", new Date() ) );
        session.save( new Event( "A follow up event", new Date() ) );
        session.getTransaction().commit();
        session.close();

        // now lets pull events from the database and list them
        session = sessionFactory.openSession();
        session.beginTransaction();
        List result = session.createQuery( "from Event" ).list();
        for ( Event event : (List<Event>) result ) {
            System.out.println( "Event (" + event.getDate() + ") : " + event.getTitle() );
        }
        session.getTransaction().commit();
        session.close();
    }
}

3. session獲取實體物件

Session session = sessionFactory.openSession();
session.beginTransaction();
session.save( new Event( "Our very first event!", new Date() ) );
session.save( new Event( "A follow up event", new Date() ) );
session.getTransaction().commit();
session.close();

4.session獲取實體物件列表

session = sessionFactory.openSession();
session.beginTransaction();
List result = session.createQuery( "from Event" ).list();
for ( Event event : (List<Event>) result ) {
    System.out.println( "Event (" + event.getDate() + ") : " + event.getTitle() );
}
session.getTransaction().commit();
session.close();

5. hibernate APIs和註解對映

5.1 Java類實體註解

實體類示例

package org.hibernate.tutorial.annotations;

import java.util.Date;
import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.Id;
import javax.persistence.Table;
import javax.persistence.Temporal;
import javax.persistence.TemporalType;

import org.hibernate.annotations.GenericGenerator;

@Entity
@Table( name = "EVENTS" )
public class Event {
    private Long id;

    private String title;
    private Date date;

    public Event() {
        // this form used by Hibernate
    }

    public Event(String title, Date date) {
        // for application use, to create new events
        this.title = title;
        this.date = date;
    }

    @Id
    @GeneratedValue(generator="increment")
    @GenericGenerator(name="increment", strategy = "increment")
    public Long getId() {
        return id;
    }

    private void setId(Long id) {
        this.id = id;
    }

    @Temporal(TemporalType.TIMESTAMP)
    @Column(name = "EVENT_DATE")
    public Date getDate() {
        return date;
    }

    public void setDate(Date date) {
        this.date = date;
    }

    public String getTitle() {
        return title;
    }

    public void setTitle(String title) {
        this.title = title;
    }
}

識別類作為一個實體

@Entity
@Table( name = "EVENTS" )
public class Event {
    ...
}

識別識別符號的屬性

@Id
@GeneratedValue(generator="increment")
@GenericGenerator(name="increment", strategy = "increment") //一種主鍵生成策略
public Long getId() {
    return id;
}

識別基本屬性

public String getTitle() {
    return title;
}

@Temporal(TemporalType.TIMESTAMP)
@Column(name = "EVENT_DATE")
public Date getDate() {
    return date;
}

6. JPA

暫時用不到，此處先略過