我正在开发一个项目，第一次使用JPA、Hibernate等技术。我遇到了事务未能提交的问题。我使用了下面这个类User：
package org.tomasherman.JBTBackup.Resource.Entity;
import javax.persistence.*;
import java.io.Serializable;
@Entity
@Table(name = "users")
public class User implements Serializable {
@Id
@GeneratedValue
private int id;
private String login;
private String email;
private String password;
private int credit;
public User() {
}
public User(String login, String email, String password, int credit) {
setLogin(login);
setEmail(email);
setPassword(password);
setCredit(credit);
}
public int getId() {
return id;
}
public void setId(int id) {
this.id = id;
}
public String getLogin() {
return login;
}
public void setLogin(String login) {
this.login = login;
}
public String getEmail() {
return email;
}
public void setEmail(String email) {
this.email = email;
}
public String getPassword() {
return password;
}
public void setPassword(String password) {
this.password = password;
}
public int getCredit() {
return credit;
}
public void setCredit(int credit) {
this.credit = credit;
}
}
使用HSQL数据库将其持久化到内存表中。 persistence.xml文件如下所示：
<?xml version="1.0" encoding="UTF-8"?>
<persistence-unit name="JBTBackupPersistance">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<class>org.tomasherman.JBTBackup.Resource.Entity.User</class>
<properties>
<property name="hibernate.connection.url" value="jdbc:hsqldb:file:./database/database.hsql"/>
<property name="hibernate.dialect" value="org.hibernate.dialect.HSQLDialect"/>
<property name="hibernate.connection.driver_class" value="org.hsqldb.jdbcDriver"/>
<property name="hibernate.connection.username" value="SA"/> <!--default hsql login-->
<property name="hibernate.connection.password" value=""/>
<property name="hibernate.archive.autodetection" value="class"/>
<property name="hibernate.show_sql" value="true"/>
<property name="hibernate.format_sql" value="true"/>
<property name="connection.shutdown" value="true"/>
</properties>
</persistence-unit>
并在类似于以下的JUnit测试中进行测试：
package org.tomasherman.JBTBackup.Resource.Entity;
import org.junit.After;
import org.junit.Before;
import org.junit.Test;
import javax.persistence.EntityManager;
import javax.persistence.EntityManagerFactory;
import javax.persistence.Persistence;
/**
* Created by IntelliJ IDEA.
* User: arg
* Date: Jun 29, 2010
* Time: 11:24:35 PM
* To change this template use File | Settings | File Templates.
*/
public class UserTest {
private EntityManagerFactory emf;
private EntityManager em;
private final User u1 = new User("and","now","for",1234);
private final User u2 = new User("something","completely","different",123123123);
private final User u3 = new User("a","man","with",123123123);
@Before
public void initEmfAndEm() {
emf = Persistence.createEntityManagerFactory("JBTBackupPersistance");
em = emf.createEntityManager();
}
@After
public void cleanup() {
em.close();
}
@Test
public void emptyTest() {
System.out.println(em.createQuery("from User").getResultList().size());
if(em.getTransaction().isActive()){
System.out.println("FFfffffffffFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU");
System.out.println("FFfffffffffFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU");
System.out.println("FFfffffffffFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU");
System.out.println("FFfffffffffFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU");
System.out.println("FFfffffffffFFFFUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUUU");
}else{
em.getTransaction().begin();
em.persist(u1);
em.persist(u2);
em.persist(u3);
em.getTransaction().commit();
}
System.out.println(em.createQuery("from User").getResultList().size());
}
}
现在的问题是插入操作经常无法写入数据库。测试的输出结果如下：
...some hibernate stuff...
Hibernate:
select
user0_.id as id0_,
user0_.credit as credit0_,
user0_.email as email0_,
user0_.login as login0_,
user0_.password as password0_
from
users user0_
20
Hibernate:
insert
into
users
(id, credit, email, login, password)
values
(null, ?, ?, ?, ?)
Hibernate:
insert
into
users
(id, credit, email, login, password)
values
(null, ?, ?, ?, ?)
Hibernate:
insert
into
users
(id, credit, email, login, password)
values
(null, ?, ?, ?, ?)
Hibernate:
select
user0_.id as id0_,
user0_.credit as credit0_,
user0_.email as email0_,
user0_.login as login0_,
user0_.password as password0_
from
users user0_
23
因此，实体存储在数据库的内存中，但是在单元测试后检查数据库时，没有数据。然而，它会不时地提交。
如果有人能帮我，那就太棒了。
编辑： 如果对任何人有帮助，这里有一个库版本列表（以Maven格式）：
<dependency>
<groupId>javax.transaction</groupId>
<artifactId>jta</artifactId>
<version>1.1</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-api</artifactId>
<version>1.6.0</version>
</dependency>
<dependency>
<groupId>commons-collections</groupId>
<artifactId>commons-collections</artifactId>
<version>20040616</version>
</dependency>
<dependency>
<groupId>org.hsqldb</groupId>
<artifactId>hsqldb</artifactId>
<version>2.0.0</version>
</dependency>
<dependency>
<groupId>hibernate</groupId>
<artifactId>hibernate-entitymanager</artifactId>
<version>3.4.0.GA</version>
</dependency>
<dependency>
<groupId>org.slf4j</groupId>
<artifactId>slf4j-simple</artifactId>
<version>1.6.0</version>
</dependency>
<dependency>
<groupId>org.hibernate</groupId>
<artifactId>hibernate-search</artifactId>
<version>3.1.0.GA</version>
</dependency>
<dependency>
<groupId>hibernate</groupId>
<artifactId>hibernate</artifactId>
<version>3.0.5</version>
</dependency>
<dependency>
<groupId>javax.persistence</groupId>
<artifactId>persistence-api</artifactId>
<version>1.0</version>
</dependency>
更新2： 另一个有趣的事情是，如果我在测试的结尾添加Thread.sleep(1000);，所有的事务都会被提交。这可能是因为程序完成得比数据库更新快吗？
hibernate.connection.shutdown。你在之前的 hsqldb 版本（1.8.0.10）中是否遇到了相同的问题？由于你正在使用 maven，测试应该很容易。我无法重现这个问题。 - Pascal Thivent