Question

我正在尝试使用EclipseLink作为jpa提供程序执行简单的JPA映射。

[![Persistence and Project Structure][1]][1]

上面的图片解释了项目结构和persistence.xml。上面提到的数据库细节，我已经检查了oracle toad。我可以访问指定的模式，如下所示。

[![opening database connection ][2]][2]

在上图中，您可以看到连接。

following is the POJO

它是一个简单的pojo类，它有一个字段，我定义为主键和其他字段。

package com.sun.arise;

import javax.persistence.Column;
import javax.persistence.Entity;
import javax.persistence.GeneratedValue;
import javax.persistence.GenerationType;
import javax.persistence.Id;
import javax.persistence.Table;




@Entity
@Table(name="Sun")
public class Sun {

  @Id
  @GeneratedValue(strategy=GenerationType.AUTO)
private int sunid;

  @Column(name="DAY")
private String day;

  @Column(name="MONTH")
private String month;


  public String getDay() {
  return day;
  }


  public void setDay(String day) {
  this.day = day;
  }


  public String getMonth() {
  return month;
  }


  public void setMonth(String month) {
  this.month = month;
  }


public int getSunId()
{
  return sunid;
}


@Override
public String toString()
{
  return getSunId()+"\n"+getDay()+"\n"+getMonth();
}
}

坚持pojo以上我写了下面的课

package com.sun.sunset;


import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;


import com.sun.arise.Sun;


public class TestSun {

public static void main(String args[])
{
  String persistenceUnitName="myAttemptAtJPA";
  EntityManagerFactory emf = Persistence.createEntityManagerFactory(persistenceUnitName);
  EntityManager em = emf.createEntityManager();
  Sun z = new Sun();
  z.setDay("Saturday");
  z.setMonth("January");

  em.getTransaction().begin();
  em.persist(z);
  em.getTransaction().commit();

}
}

执行后我得到以下错误我不确定错误是因为它无法在META-INF文件夹中找到persistence.xml。它无法找到网址和驱动程序。

[EL Fine]: server: 2016-06-14 17:02:31.478--Thread(Thread[main,5,main])--Configured server platform: org.eclipse.persistence.platform.server.NoServerPlatform
[EL Config]: metadata: 2016-06-14 17:02:31.592--ServerSession(19166103)--Thread(Thread[main,5,main])--The access type for the persistent class [class com.sun.arise.Sun] is set to [FIELD].
[EL Config]: metadata: 2016-06-14 17:02:31.612--ServerSession(19166103)--Thread(Thread[main,5,main])--The alias name for the entity class [class com.sun.arise.Sun] is being defaulted to: Sun.
[EL Config]: metadata: 2016-06-14 17:02:31.627--ServerSession(19166103)--Thread(Thread[main,5,main])--The column name for element [sunid] is being defaulted to: SUNID.
[EL Info]: 2016-06-14 17:02:31.65--ServerSession(19166103)--Thread(Thread[main,5,main])--EclipseLink, version: Eclipse Persistence Services - 2.6.3.v20160428-59c81c5
[EL Severe]: ejb: 2016-06-14 17:02:31.652--ServerSession(19166103)--Thread(Thread[main,5,main])--Exception [EclipseLink-4021] (Eclipse Persistence Services - 2.6.3.v20160428-59c81c5): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Unable to acquire a connection from driver [null], user [null] and URL [null].  Verify that you have set the expected driver class and URL.  Check your login, persistence.xml or sessions.xml resource.  The jdbc.driver property should be set to a class that is compatible with your database platform
Exception in thread "main" javax.persistence.PersistenceException: Exception [EclipseLink-4021] (Eclipse Persistence Services - 2.6.3.v20160428-59c81c5): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Unable to acquire a connection from driver [null], user [null] and URL [null].  Verify that you have set the expected driver class and URL.  Check your login, persistence.xml or sessions.xml resource.  The jdbc.driver property should be set to a class that is compatible with your database platform
  at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:815)
  at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.getAbstractSession(EntityManagerFactoryDelegate.java:205)
  at org.eclipse.persistence.internal.jpa.EntityManagerFactoryDelegate.createEntityManagerImpl(EntityManagerFactoryDelegate.java:305)
  at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManagerImpl(EntityManagerFactoryImpl.java:337)
  at org.eclipse.persistence.internal.jpa.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:303)
  at com.sun.sunset.TestSun.main(TestSun.java:15)
Caused by: Exception [EclipseLink-4021] (Eclipse Persistence Services - 2.6.3.v20160428-59c81c5): org.eclipse.persistence.exceptions.DatabaseException
Exception Description: Unable to acquire a connection from driver [null], user [null] and URL [null].  Verify that you have set the expected driver class and URL.  Check your login, persistence.xml or sessions.xml resource.  The jdbc.driver property should be set to a class that is compatible with your database platform
  at org.eclipse.persistence.exceptions.DatabaseException.unableToAcquireConnectionFromDriverException(DatabaseException.java:383)
  at org.eclipse.persistence.sessions.DefaultConnector.connect(DefaultConnector.java:91)
  at org.eclipse.persistence.sessions.DatasourceLogin.connectToDatasource(DatasourceLogin.java:162)
  at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.setOrDetectDatasource(DatabaseSessionImpl.java:207)
  at org.eclipse.persistence.internal.sessions.DatabaseSessionImpl.loginAndDetectDatasource(DatabaseSessionImpl.java:760)
  at org.eclipse.persistence.internal.jpa.EntityManagerFactoryProvider.login(EntityManagerFactoryProvider.java:265)
  at org.eclipse.persistence.internal.jpa.EntityManagerSetupImpl.deploy(EntityManagerSetupImpl.java:731)
  ... 5 more

如果需要更多信息，请告诉我。谢谢

  [1]: http://i.stack.imgur.com/PD0Ru.png
  [2]: http://i.stack.imgur.com/iXEN0.png

Answer 1

没有此类持久性属性javax.persistence.driver等。

他们是

javax.persistence.jdbc.driver
javax.persistence.jdbc.user

等

JPA连接eclipselink作为提供者，oracle作为数据库

1 个答案: