Question

我正在尝试从带注释的EJB实体创建数据库。使用：Eclipse，Ant工具，Apache Tomee服务器，OpenJPA，JEE / EJB，MySQL数据库。

我的应用程序在注入实体管理器期间失败（假设在注释的实体类之后触发数据库创建）。一些关键的应用程序部分：

异常我看起来像这样：

prepare-database:
     [echo] Inserting default user into database.
     [java] Dec 09, 2013 9:45:29 AM org.apache.openejb.client.EventLogger log
     [java] INFO: RemoteInitialContextCreated{providerUri=http://127.0.0.1:8080/tomee/ejb}
     [java] Bean found
     [java] Exception in thread "main" javax.ejb.EJBException: The bean encountered a non-application exception; nested exception is: 
     [java]     <openjpa-2.2.0-r422266:1244990 nonfatal general error> org.apache.openjpa.persistence.PersistenceException: There were errors initializing your configuration: <openjpa-2.2.0-r422266:1244990 fatal user error> org.apache.openjpa.util.UserException: A connection could not be obtained for driver class "null" and URL "null".  You may have specified an invalid URL.
     [java]     at org.apache.openjpa.jdbc.schema.DataSourceFactory.newConnectException(DataSourceFactory.java:255)
     [java]     at org.apache.openjpa.jdbc.schema.DataSourceFactory.installDBDictionary(DataSourceFactory.java:241)
     [java]     at org.apache.openjpa.jdbc.conf.JDBCConfigurationImpl.getConnectionFactory(JDBCConfigurationImpl.java:733)
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
     [java]     at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
     [java]     at java.lang.reflect.Method.invoke(Method.java:606)
     [java]     at org.apache.openjpa.lib.conf.ConfigurationImpl.instantiateAll(ConfigurationImpl.java:295)
     [java]     at org.apache.openjpa.conf.OpenJPAConfigurationImpl.instantiateAll(OpenJPAConfigurationImpl.java:1671)
     [java]     at org.apache.openjpa.kernel.AbstractBrokerFactory.makeReadOnly(AbstractBrokerFactory.java:646)
     [java]     at org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:203)
     [java]     at org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:156)
     [java]     at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:227)
     [java]     at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:60)
     [java]     at org.apache.openejb.assembler.classic.ReloadableEntityManagerFactory.createEntityManager(ReloadableEntityManagerFactory.java:160)
     [java]     at org.apache.openejb.persistence.JtaEntityManagerRegistry.getEntityManager(JtaEntityManagerRegistry.java:115)
     [java]     at org.apache.openejb.persistence.JtaEntityManager.getEntityManager(JtaEntityManager.java:80)
     [java]     at org.apache.openejb.persistence.JtaEntityManager.persist(JtaEntityManager.java:126)
     [java]     at rs.ac.uns.ftn.informatika.mbs2.vezbe09.primer01.server.session.InitBean.init(InitBean.java:22)
     [java]     at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)

and so on ....

用于触发数据库生成的Ant任务：

<target name="prepare-database">
        <echo message="Inserting default user into database."/>
        <java classname="rs.ac.uns.ftn.informatika.mbs2.vezbe09.primer01.client.InitClient"  fork="true">
            <classpath>
                <pathelement path="${build}" />
                <fileset dir="${lib}">
                    <include name="*.jar"/>
                </fileset>
            </classpath>
        </java>
</target>

“InitClient”类（从此ant任务开始）在其主要方法中有下一个代码：

Context ctx = new InitialContext();
            Init init = (Init) ctx.lookup("InitBeanRemote");
            System.out.println("Bean found!");
            init.init();

“InitBean”类，其中注入了实体管理器：

@Stateless
@Remote(Init.class)
public class InitBean implements Init {

    @PersistenceContext(unitName = "Vezbe09")
    EntityManager em;

    public void init() {

        Korisnik korisnik = new Korisnik("Admin", "Admin", "admin", "admin");
        em.persist(korisnik);
          //...
        }
}

persistent.xml - 持久性单元定义：

<persistence-unit name="Vezbe09" transaction-type="JTA">
    <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
    <jta-data-source>Vezbe09DS</jta-data-source>
    <properties>
        <property name="openjpa.jdbc.SynchronizeMappings" value="buildSchema(ForeignKeys=true)" />
        <property name="openjpa.jdbc.DBDictionary" value="mysql" />
        <property name="openjpa.Log" value="DefaultLevel=WARN, Tool=INFO" />
    </properties>
</persistence-unit>

tomee.xml配置文件中的数据源定义：

<Resource id="Vezbe09DS" type="DataSource">
    JdbcDriver          com.mysql.jdbc.Driver
    JdbcUrl             jdbc:mysql://127.0.0.1:3306/Vezbe09
    UserName            root
    Password            123
    JtaManaged          true
    DefaultAutoCommit   false
</Resource>

（奇怪的是我以前运行过这个应用程序，过去工作正常。我正在获取数据库，并运行应用程序。）感谢任何建议。

Answer 1

我的错误！（还在学习）。

以上代码和设置都很好。我认为持久性提供程序（openJPA）不仅创建数据库表，还创建数据库本身。我认为，因为数据源定义中包含“JdbcUrl属性”（包含数据库名称）。显然，我需要创建数据库，而持久性提供程序只是创建现有数据库的表。所以，我已经（明确地）使用mysql终端命令“create database Vezbe09”创建了数据库。，部署我的应用程序，在触发openJPA的ant任务上面运行，我在我的数据库中得到了表。

OpenJPA不从EJB实体生成/映射数据库表

1 个答案: