java – Eclipselink JPA,Oracle,Weblogic,Calling Persist不提交数据库
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我刚开始看看java持久性(目前使用eclipse的eclipselink默认提供程序).基本上只是创建一个对象并尝试将其持久化到db(Oracle).我的理解是,当方法返回时,默认事务性应该将新对象提交到数据库,但似乎没有发生任何事情.有任何想法吗？
@Stateless
public class RegisterUser implements RegisterUserLocal {
@PersistenceContext
private EntityManager entityManager;
public void registerNewUser(String username, String password){
User user = new User();
user.setPassword(password);
user.setUsername(username);
entityManager.persist(user);
entityManager.getTransaction().commit();
}
}
persistence.xml中：
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="1.0" 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_1_0.xsd">
<persistence-unit name="SCBCDEntities" transaction-type="RESOURCE_LOCAL">
<provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
<class>examples.persistence.User</class>
<properties>
<property name="eclipselink.target-server" value="WebLogic_10"/>
<property name="eclipselink.jdbc.driver" value="oracle.jdbc.OracleDriver"/>
<property name="eclipselink.jdbc.url" value="jdbc:oracle:thin:@localhost:1521:db4"/>
<property name="eclipselink.jdbc.user" value="SCBCD"/>
<property name="eclipselink.jdbc.password" value="123456"/>
<property name="eclipselink.logging.level" value="FINEST"/>
</properties>
</persistence-unit>
</persistence>
实体类：
@Entity
@Table(name="USERS")
public class User implements Serializable {
private static final long serialVersionUID = 1L;
@Id
private String username;
private String password;
public User() {
}
public String getUsername() {
return this.username;
}
public void setUsername(String username) {
this.username = username;
}
public String getPassword() {
return this.password;
}
public void setPassword(String password) {
this.password = password;
}
}
此外,为了回复对此问题的回复,使用我列出的代码,日志显示执行提交(为简洁起见,删除了一些细节)
[EL Finest]: 2010-01-05 22:58:07.468--UnitOfWork(25499586)--Thread(Thread[[ACTIVE] ExecuteThread: '0' for queue: 'weblogic.kernel.
Default (self-tuning)',5,Pooled Threads])--PERSIST operation called on: examples.persistence.User@191ed96.
<Jan 5, 2010 10:58:07 PM EST> <Debug> <JTA2PC> <BEA-000000> <BEA1-001959ECF50B251A451D: [EJB examples.session.stateless.RegisterUs
er.registerNewUser(java.lang.String,java.lang.String)]: ServerTransactionImpl.commit()>
<Jan 5, 2010 10:58:07 PM EST> <Debug> <JTA2PC> <BEA-000000> <BEA1-001959ECF50B251A451D: [EJB examples.session.stateless.RegisterUs
er.registerNewUser(java.lang.String,java.lang.String)]: TX[BEA1-001959ECF50B251A451D] active-->pre_preparing
<Jan 5, 2010 10:58:07 PM EST> <Debug> <JTA2PC> <BEA-000000> <SC[mr_domain+AdminServer] active-->pre-preparing
er.registerNewUser(java.lang.String,java.lang.String)]: TX[BEA1-001959ECF50B251A451D] prepared-->committing
<Jan 5, 2010 10:58:07 PM EST> <Debug> <JTA2PC> <BEA-000000> <SC[mr_domain+AdminServer] pre-prepared-->committed
er.registerNewUser(java.lang.String,java.lang.String)]: TX[BEA1-001959ECF50B251A451D] committing-->committed
...
...
但如果我在坚持之后添加’flush’,我会得到’notransaction’……
[EL Finest]: 2010-01-05 22:44:55.218--UnitOfWork(113017)--Thread(Thread[[ACTIVE] ExecuteThread: '2' for queue: 'weblogic.kernel.De
fault (self-tuning)',5,Pooled Threads])--PERSIST operation called on: examples.persistence.User@1717dea.
<Jan 5, 2010 10:44:55 PM EST> <Info> <EJB> <BEA-010227> <EJB Exception occurred during invocation from home or business: weblogic.
ejb.container.internal.StatelessEJBLocalHomeImpl@1509b8 threw exception: javax.persistence.TransactionRequiredException:
Exception Description: No transaction is currently active>
<Jan 5, 2010 10:44:55 PM EST> <Debug> <JTA2PC> <BEA-000000> <BEA1-001859ECF50B251A451D: [EJB examples.session.stateless.RegisterUs
er.registerNewUser(java.lang.String,java.lang.String)]: TX[BEA1-001859ECF50B251A451D] active-->rolling back
...
...
解决方法:
经过大量调查,包括尝试容器管理和用户管理的事务,似乎问题是事务类型被指定为RESOURCE_LOCAL.在这种情况下,以下规则适用：
* You must use the EntityManagerFactory to get an EntityManager
* The resulting EntityManager instance is a PersistenceContext/Cache
* An EntityManagerFactory can be injected via the @PersistenceUnit annotation only (not @PersistenceContext)
* You are not allowed to use @PersistenceContext to refer to a unit of type RESOURCE_LOCAL
* You must use the EntityTransaction API to begin/commit around every call to your EntityManger
* Calling entityManagerFactory.createEntityManager() twice results in two separate EntityManager instances and therefor two separate PersistenceContexts/Caches.
* It is almost never a good idea to have more than one instance of an EntityManager in use (don't create a second one unless you've destroyed the first)
在我的例子中,我需要使用manager工厂来访问entitymanager,并使用persistenceUnit而不是persistenceContext.以下代码工作得很好：
@Stateless
@TransactionManagement(TransactionManagementType.CONTAINER)
public class RegisterUser implements RegisterUserLocal {
@PersistenceUnit(unitName = "SCBCDEntities")
private EntityManagerFactory factory;
public void registerNewUser(String username, String password) {
EntityManager entityManager = factory.createEntityManager();
EntityTransaction entityTransaction = entityManager.getTransaction();
entityTransaction.begin();
User user = new User();
user.setPassword(password);
user.setUsername(username);
entityManager.persist(user);
entityTransaction.commit();
}
}
有关配置事务和persistence.xml中的设置的其他信息,请访问：http://openejb.apache.org/3.0/jpa-concepts.html
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