我是Hibernate和JPA的新手,我在尝试按照JPA规范实现使用Hibernate的教程时遇到以下问题。
我有这些课程:
1) HelloWorldClient
类,我的应用程序的入口点,包含main
方法:
package client;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.EntityTransaction;
import javax.persistence.Persistence;
import entity.Message;
public class HelloWorldClient {
public static void main(String[] args) {
EntityManagerFactory emf = Persistence.createEntityManagerFactory("merging");
EntityManager em = emf.createEntityManager();
EntityTransaction txn = em.getTransaction();
txn.begin();
Message message = new Message("Hello"); //transient state
em.persist(message); //persistent state
txn.commit();
em.close();
message.setText("Hi"); //modifying the detached state of message
EntityManager em2 = emf.createEntityManager();
EntityTransaction txn2 = em2.getTransaction();
txn2.begin();
//the returned mergedMessage is a persistent object
//any changes to mergedMessage will be dirty checked when the txn2 will be committed and updated in the database
Message mergedMessage = em2.merge(message);
txn2.commit();
em2.close();
//Detaching objects explicitly
/*
EntityManager em3 = emf.createEntityManager();
EntityTransaction txn3 = em.getTransaction();
txn3.begin();
Message msg = new Message("Howdy"); //transient state
em.persist(msg); //persistent state
em.detach(msg); //detaching the message object explicitly
txn3.commit();
em3.close();
*/
}
}
2)映射到数据库表的 Message
实体类:
package entity;
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="message")
public class Message {
@Id
@GeneratedValue(strategy=GenerationType.AUTO)
@Column(name="ID")
private Long id;
@Column(name="TEXT")
private String text;
public Message() {}
public Message(String text) {
this.text = text;
}
public void setText(String text) {
this.text = text;
}
}
3)最后,我的应用程序的 persistence.xml
文件夹中包含 META-INF
配置文件:
<?xml version="1.0" encoding="UTF-8"?>
<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" xmlns="http://java.sun.com/xml/ns/persistence">
<persistence-unit name="merging" transaction-type="RESOURCE_LOCAL">
<properties>
<!-- Database connection settings -->
<property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver" />
<property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/hello-world" />
<property name="javax.persistence.jdbc.user" value="root" />
<property name="javax.persistence.jdbc.password" value="myPassword" />
<!-- SQL dialect -->
<property name="hibernate.dialect" value="org.hibernate.dialect.MySQLDialect" />
<!-- Create/update tables automatically using mapping metadata -->
<property name="hibernate.hbm2ddl.auto" value="update" />
<!-- Pretty print the SQL in the log file and console -->
<property name="hibernate.format_sql" value="true" />
</properties>
</persistence-unit>
</persistence>
当我尝试运行我的应用程序时,我在stacktrace中获取此错误消息:
Picked up JAVA_TOOL_OPTIONS: -javaagent:/usr/share/java/jayatanaag.jar
Exception in thread "main" java.lang.AbstractMethodError: org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl$4.getConfigurationValues()Ljava/util/Map;
at org.hibernate.boot.registry.classloading.internal.ClassLoaderServiceImpl.withTccl(ClassLoaderServiceImpl.java:404)
at org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.build(EntityManagerFactoryBuilderImpl.java:842)
at org.hibernate.jpa.HibernatePersistenceProvider.createEntityManagerFactory(HibernatePersistenceProvider.java:75)
at org.hibernate.ejb.HibernatePersistence.createEntityManagerFactory(HibernatePersistence.java:54)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:55)
at javax.persistence.Persistence.createEntityManagerFactory(Persistence.java:39)
at client.HelloWorldClient.main(HelloWorldClient.java:14)
答案 0 :(得分:8)
我在尝试做hibernate教程时遇到了同样的问题。这通常意味着您添加到构建路径的jar文件之间存在兼容性问题。
在你的情况下,似乎是这样 的 org.hibernate.jpa.boot.internal.EntityManagerFactoryBuilderImpl.getConfigurationValues()强> 在最新版本中作为抽象方法出现,因此出现上述错误。尝试将JPA jar更改为以前的版本,这可能会解决问题;这对我的情况有帮助。
答案 1 :(得分:1)
我遇到了同样的问题,当我检查了Maven存储库中的hibernate-entity管理器时,我发现我没有在我的POM.xml中指定最新版本。一旦我更新到最新版本,它修复了问题。