【发布时间】：2013-06-07 00:02:34
【问题描述】：
我创建了一个小型 JPA 项目来保存学生记录。我使用 Oracle 数据库。我使用 OpenJPA 作为 JPa 提供者。
我已经正确创建了学生表和相关序列。
学生实体课
@Entity
@Table(name = "Student")
public class Student implements Serializable {
private int id;
private String name;
private static final long serialVersionUID = 1L;
public Student() {
super();
}
@Id
@Column(name = "ID")
@SequenceGenerator(name = "TRAIN_SEQ", sequenceName = "STUDENT_SEQ")
@GeneratedValue(strategy = GenerationType.SEQUENCE, generator = "TRAIN_SEQ")
public int getId() {
return this.id;
}
public void setId(int id) {
this.id = id;
}
@Column(name = "NAME")
public String getName() {
return this.name;
}
public void setName(String name) {
this.name = name;
}
persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0"
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">
<persistence-unit name="JPAOracleDemo">
<provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
<class>com.jpa.demo.model.Student</class>
<properties>
<property name="openjpa.ConnectionURL" value="jdbc:oracle:thin:@TEST:50111:TESTPEGAD1" />
<property name="openjpa.ConnectionDriverName" value="oracle.jdbc.driver.OracleDriver" />
<property name="openjpa.ConnectionUserName" value="admin" />
<property name="openjpa.ConnectionPassword" value="admin" />
<property name="openjpa.RuntimeUnenhancedClasses" value="supported" />
<property name="openjpa.jdbc.Schema" value="MYSCHEMA" />
</properties>
</persistence-unit>
</persistence>
客户端类
OpenJPAEntityManager em = JPAUtil.getEntityManager();
OpenJPAEntityTransaction tx = em.getTransaction();
tx.begin();
// Create the instance of Employee Entity class
Student student = new Student();
student.setName("A.Ramesh");
// JPA API to store the Student instance on the database.
em.persist(student);
tx.commit();
em.close();
System.out.println("Done...");
实用类
private static OpenJPAEntityManagerFactory emf = OpenJPAPersistence
.createEntityManagerFactory("JPAOracleDemo", "META-INF/persistence.xml");
private static OpenJPAEntityManager entManager;
/**
* No need to create any instance for this Util.
*/
private JPAUtil() {
}
/**
* Get {@link EntityManager}.
*
* @return the {@link EntityManager}
*/
public static OpenJPAEntityManager getEntityManager() {
if (entManager == null || !entManager.isOpen()) {
entManager = emf.createEntityManager();
}
return entManager;
}
数据成功保存在学生表中，但出现以下错误
Exception in thread "Attachment 60230" java.lang.UnsupportedOperationException: cannot get the capability, performing dispose of the retransforming environment
at com.ibm.tools.attach.javaSE.Attachment.loadAgentLibraryImpl(Native Method)
at com.ibm.tools.attach.javaSE.Attachment.loadAgentLibrary(Attachment.java:253)
at com.ibm.tools.attach.javaSE.Attachment.parseLoadAgent(Attachment.java:235)
at com.ibm.tools.attach.javaSE.Attachment.doCommand(Attachment.java:154)
at com.ibm.tools.attach.javaSE.Attachment.run(Attachment.java:116)
Exception in thread "main" java.lang.UnsupportedOperationException: cannot get the capability, performing dispose of the retransforming environment
at sun.instrument.InstrumentationImpl.isRetransformClassesSupported0(Native Method)
at sun.instrument.InstrumentationImpl.isRetransformClassesSupported(InstrumentationImpl.java:124)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:48)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:37)
at java.lang.reflect.Method.invoke(Method.java:600)
at org.apache.openjpa.enhance.ClassRedefiner.canRedefineClasses(ClassRedefiner.java:123)
at org.apache.openjpa.enhance.ManagedClassSubclasser.prepareUnenhancedClasses(ManagedClassSubclasser.java:122)
at org.apache.openjpa.kernel.AbstractBrokerFactory.loadPersistentTypes(AbstractBrokerFactory.java:304)
at org.apache.openjpa.kernel.AbstractBrokerFactory.initializeBroker(AbstractBrokerFactory.java:228)
at org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:202)
at org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:156)
at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:213)
at com.ibm.ws.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:45)
at com.ibm.ws.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:30)
at com.jpa.demo.util.JPAUtil.getEntityManager(JPAUtil.java:32)
at com.jpa.demo.client.JPAClient.main(JPAClient.java:13)
1045 JPAOracleDemo INFO [main] openjpa.Enhance - Creating subclass for "[class com.jpa.demo.model.Student]". This means that your application will be less efficient and will consume more memory than it would if you ran the OpenJPA enhancer. Additionally, lazy loading will not be available for one-to-one and many-to-one persistent attributes in types using field access; they will be loaded eagerly instead.
Done...
Java 版本
JDK 1.6
有人请告诉我这里有什么问题吗？
更新：
我为此开发使用了 IBM Rational Software Architect for Websphere Software。这个问题出在这个 IDE 上。当我默认创建 JPA 项目时，它会添加 IBM jre。我刚刚删除了 IBM jre 并尝试使用 SUN jre 然后它成功了。请告诉我为什么这个功能不支持 IBM jre？
【问题讨论】：
标签： java jakarta-ee jpa openjpa ibm-rad