Question

关于这一点必须有很多问题，我已经阅读了一些，但答案仍然没有得到答案。我是JPA的新手，我只是想测试一个简单的应用程序，看看我是否可以正确配置它。它是一个独立的应用程序，意味着它不会与Web服务器或任何东西一起运行。实体类看起来像：

@Entity
public class Person{

    @Id
    private String userID = null;

    @Transient
    private UserState userState = null;

    private String email = null;
    private String name = null;


    public Person(){
        userID = null;
        email = null;
        name = null;
        userState = null;
    }

    public String getUserID() {
        return userID;
    }

    public void setUserID(String userID) {
        this.userID = userID;
    }

    public String getEmail() {
        return email;
    }

    public void setEmail(String email) {
        this.email = email;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public UserState getUserState() {
        return userState;
    }

    public void setUserState(UserState userState) {
        this.userState = userState;
    }

}

主要：

public class PersistenceTest {

    public static void main(String[] args) {
        System.out.println("creating person");
        Person p = new Person();
        p.setUserID("GregR");
        p.setEmail("Gregory@company.de");
        p.setUserState(UserState.ACTIVE);
        System.out.println("done creating person GregR");


        EntityManagerFactory factory = Persistence.createEntityManagerFactory(PersonService.PERSISTENCE_UNIT_NAME);
        System.out.println("factory initialized");
        EntityManager manager = factory.createEntityManager();
        System.out.println("EntityManager initialized");
        PersonService service = new PersonService(manager);
        System.out.println("service initialized");

        System.out.println("Beginning transaction");
        manager.getTransaction().begin();
        System.out.println("Transaction begun");

        System.out.println("attempting to persist person");
        service.persistEntity(p);
        manager.getTransaction().commit();
        System.out.println("person persisted");

        System.out.println("beginning cleanup");
        manager.close();
        factory.close();
        System.out.println("Cleanup has completed");
    }
}

配置：

<?xml version="1.0"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="1.0">
    <persistence-unit name="PersonService" transaction-type="RESOURCE_LOCAL">
        <provider>org.apache.openjpa.persistence.PersistenceProviderImpl</provider>
        <class>de.hol.persistable.entities.Person</class>
        <properties>
            <property name="javax.persistence.jdbc.driver" value="com.mysql.jdbc.Driver"/>
            <property name="javax.persistence.jdbc.url" value="jdbc:mysql://localhost:3306/ConnectionWikisDB"/>
            <property name="javax.persistence.jdbc.user" value="GregR"/>
            <property name="javax.persistence.jdbc.password" value="myPassword"/>
        </properties>
    </persistence-unit>
</persistence>

控制台打印输出：

creating person
done creating person GReeder
factory initialized
47  PersonService  INFO   [main] openjpa.Runtime - Starting OpenJPA 2.3.0
110  PersonService  INFO   [main] openjpa.jdbc.JDBC - Using dictionary class "org.apache.openjpa.jdbc.sql.MySQLDictionary".
306  PersonService  INFO   [main] openjpa.jdbc.JDBC - Connected to MySQL version 5.5 using JDBC driver MySQL-AB JDBC Driver version mysql-connector-java-5.0.8 ( Revision: ${svn.Revision} ). 
Exception in thread "main" <openjpa-2.3.0-r422266:1540826 nonfatal user error> org.apache.openjpa.persistence.ArgumentException: This configuration disallows runtime optimization, but the following listed types were not enhanced at build time or at class load time with a javaagent: "
de.hol.persistable.entities.Person".
    at org.apache.openjpa.enhance.ManagedClassSubclasser.prepareUnenhancedClasses(ManagedClassSubclasser.java:115)
    at org.apache.openjpa.kernel.AbstractBrokerFactory.loadPersistentTypes(AbstractBrokerFactory.java:312)
    at org.apache.openjpa.kernel.AbstractBrokerFactory.initializeBroker(AbstractBrokerFactory.java:236)
    at org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:212)
    at org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:155)
    at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:226)
    at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:153)
    at org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:59)
    at de.hol.persistable.PersistenceTest.main(PersistenceTest.java:24)

我的问题
我猜主要的问题是，我做错了什么。我对此非常陌生，我正试图让这个独立的应用程序工作，以便我可以扩展它以供现实世界使用。
2.我是否遗漏了除persistence.xml文件以外的其他一些配置？ 3.为独立应用程序解决此错误的最简单方法是什么？

非常感谢提前！

Answer 1

我看到你有主类，因此我假设你在Java SE环境中使用它。使其工作的最简单方法是在命令行中定义-javaagent，如下所示：

java -jar myJAR.jar -javaagent:openjpa-all-2.3.0.jar

也可以从Eclipse：运行 - >运行配置 - >在“Java应用程序”中找到您的应用程序 - ＆gt;参数 - ＆gt; VM参数 - ＆gt;添加

-javaagent:/full/path/to/openjpa-all-2.3.0.jar

Answer 2

通过检查[ManagedClassSubclasser] 1代码，您可以看到这更像是一个警告。如果要使此异常静音并通过以下方式记录警告：

<property name="openjpa.RuntimeUnenhancedClasses" value="warn"/>

Answer 3

我想在面对同样的问题时添加我的经验。如果你使用tomcat它没有实现OpenJPA的完整规范，你需要单独提供增强功能。有关增强功能，请按照此链接http://openjpa.apache.org/enhancement-with-eclipse.html上提供的说明进行操作。你会很高兴。注意：我知道您没有使用任何服务器，但是如果您想使用tomcat，那么您需要关注该链接。

使用openJPA MySQL进行运行时优化的例外情况

3 个答案: