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我想使用EclipseLink作爲jpa提供程序執行簡單的JPA映射。JPA連接eclipselink作爲提供程序和oracle作爲數據庫
[![Persistence and Project Structure][1]][1]
上面的圖解釋了項目結構和persistence.xml。 上面提到的數據庫細節，我已經檢查了甲骨文蟾蜍。我能夠訪問如下所示的指定模式。
[![opening database connection ][2]][2]
在上圖中，您可以看到連接。
following is the POJO
它是一個簡單的pojo類，它有一個字段，我將其定義爲主鍵和其他字段。
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();
}
}
堅持上述POJO我寫了下面的類
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();
}
}
執行我收到以下錯誤後 我不知道錯誤是因爲它是無法找到的persistence.xml的META-INF夾。它無法找到網址和驅動程序。
[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，請讓我知道。 感謝
[1]: http://i.stack.imgur.com/PD0Ru.png
[2]: http://i.stack.imgur.com/iXEN0.png