Hibernate 5 入门指南-基于Envers

原文链接： http://www.cnblogs.com/htsg/p/9889636.html

1. 首先创建\META-INF\persistence.xml配置文件并做简单的配置

   <persistence xmlns="http://java.sun.com/xml/ns/persistence"
                xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
                version="2.0">
   ​
       <persistence-unit name="org.hibernate.tutorial.envers">
           <description>
              Persistence unit for the JPA tutorial of the Hibernate Getting Started Guide
           description>
   ​
           <properties>
               <property name="javax.persistence.jdbc.driver" value="com.mysql.cj.jdbc.Driver" />
               <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/databaseName?useSSL=false&serverTimezone=UTC&verifyServerCertifate=false&allowPublicKeyRetrieval=true" />
               <property name="javax.persistence.jdbc.user" value="root" />
               <property name="javax.persistence.jdbc.password" value="passwd" />
      <property name="hibernate.dialect" value="org.hibernate.dialect.MySQL8Dialect"/>
               <property name="hibernate.show_sql" value="true" />
               <property name="hibernate.format_sql" value="true"/>
               <property name="hibernate.hbm2ddl.auto" value="create" />
           properties>
   ​
       persistence-unit>
   ​
   persistence>

2. 创建实体Java类

   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;
   import org.hibernate.envers.Audited;
   ​
   @Entity
   @Table( name = "EVENTS" )
   @Audited  // <--- this tell Envers to audit (track changes to) this entity
   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;   }​ @Override public int hashCode() { int result = title.hashCode(); result = 31 * result + date.hashCode(); return result; }}

3. 向META-INF/persistence.xml文件中添加映射信息

   <class>类路径.Eventclass>

4. JUnit测试测试程序

   import java.util.Date;
   import java.util.List;
   import javax.persistence.EntityManager;
   import javax.persistence.EntityManagerFactory;
   import javax.persistence.Persistence;
   ​
   import junit.framework.TestCase;
   ​
   import org.hibernate.envers.AuditReader;
   import org.hibernate.envers.AuditReaderFactory;
   ​
   /**
    * Illustrates the set up and use of Envers.
    * 
   
    * This example is different from the others in that we really need to save multiple revisions to the entity in
    * order to get a good look at Envers in action.
    *
    * @author Steve Ebersole
    */
   public class EnversIllustrationTest extends TestCase {
    private EntityManagerFactory entityManagerFactory;
   ​
    @Override
    protected void setUp() throws Exception {
     // like discussed with regards to SessionFactory, an EntityManagerFactory is set up once for an application
     //   IMPORTANT: notice how the name here matches the name we gave the persistence-unit in persistence.xml!
     entityManagerFactory = Persistence.createEntityManagerFactory( "org.hibernate.tutorial.envers" );
    }
   ​
    @Override
    protected void tearDown() throws Exception {
     entityManagerFactory.close();
    }
   ​
    public void testBasicUsage() {
     // create a couple of events
     EntityManager entityManager = entityManagerFactory.createEntityManager();
     entityManager.getTransaction().begin();
     entityManager.persist( new Event( "Our very first event!", new Date() ) );
     entityManager.persist( new Event( "A follow up event", new Date() ) );
     entityManager.getTransaction().commit();
     entityManager.close();
   ​
     // now lets pull events from the database and list them
     entityManager = entityManagerFactory.createEntityManager();
     entityManager.getTransaction().begin();
           List result = entityManager.createQuery( "from Event", Event.class ).getResultList(); for ( Event event : result ) { System.out.println( "Event (" + event.getDate() + ") : " + event.getTitle() ); }        entityManager.getTransaction().commit();        entityManager.close();​ // so far the code is the same as we have seen in previous tutorials. Now lets leverage Envers...​ // first lets create some revisions entityManager = entityManagerFactory.createEntityManager(); entityManager.getTransaction().begin(); Event myEvent = entityManager.find( Event.class, 2L ); // we are using the increment generator, so we know 2 is a valid id myEvent.setDate( new Date() ); myEvent.setTitle( myEvent.getTitle() + " (rescheduled)" );        entityManager.getTransaction().commit();        entityManager.close();​ // and then use an AuditReader to look back through history entityManager = entityManagerFactory.createEntityManager(); entityManager.getTransaction().begin(); myEvent = entityManager.find( Event.class, 2L ); assertEquals( "A follow up event (rescheduled)", myEvent.getTitle() ); AuditReader reader = AuditReaderFactory.get( entityManager ); Event firstRevision = reader.find( Event.class, 2L, 1 ); assertFalse( firstRevision.getTitle().equals( myEvent.getTitle() ) ); assertFalse( firstRevision.getDate().equals( myEvent.getDate() ) ); Event secondRevision = reader.find( Event.class, 2L, 2 ); assertTrue( secondRevision.getTitle().equals( myEvent.getTitle() ) ); assertTrue( secondRevision.getDate().equals( myEvent.getDate() ) ); entityManager.getTransaction().commit();        entityManager.close(); }}

5. 运行测试

转载于:https://www.cnblogs.com/htsg/p/9889636.html