OpenJPA：此配置不允许运行时优化，但所列类型在构建时或类加载时没有使用javaagent进行增强

所以，经过大量的搜索（徒劳），我决定发布这篇文章。因此，我正在使用OpenJPA（2.2.0）开发这个web应用程序。执行应用程序会引发以下错误：

控制台打印输出：

<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: "
Entities.User".
    org.apache.openjpa.enhance.ManagedClassSubclasser.prepareUnenhancedClasses(ManagedClassSubclasser.java:115)
    org.apache.openjpa.kernel.AbstractBrokerFactory.loadPersistentTypes(AbstractBrokerFactory.java:312)
    org.apache.openjpa.kernel.AbstractBrokerFactory.initializeBroker(AbstractBrokerFactory.java:236)
    org.apache.openjpa.kernel.AbstractBrokerFactory.newBroker(AbstractBrokerFactory.java:212)
    org.apache.openjpa.kernel.DelegatingBrokerFactory.newBroker(DelegatingBrokerFactory.java:155)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:226)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:153)
    org.apache.openjpa.persistence.EntityManagerFactoryImpl.createEntityManager(EntityManagerFactoryImpl.java:59)
    Servlet.Registration.doPost(Registration.java:78)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:650)
    javax.servlet.http.HttpServlet.service(HttpServlet.java:731)
    org.apache.tomcat.websocket.server.WsFilter.doFilter(WsFilter.java:52)

---

您是否配置了构建时增强功能？OpenJPA需要修改类文件以使用它们，所以您应该允许它在某个时候这样做。这为如何做提供了一个很好的概述。例如，可以用maven来完成。另一种方法是运行时增强

我没有配置增强功能，在您和我的日志中，我看到了这个“Entities.User”。我说的是什么意思？回答：例如，如果代码中存在错误，请仔细检查您的代码，然后再检查我的代码。在我的例子中，它是双@Id:at列Id和at用户名！这很神奇。

只需在persistence.xml文件中添加一个提供程序，如：

<persistence-unit name="persistenceUnit">
    **<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>**
    <class>Entities.User</class>

**org.hibernate.jpa.HibernatePersistenceProvider**
实体。用户

public class Registration extends HttpServlet {
    @Override
    protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

    }


    @Override
    protected void doPost(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {

        String name = request.getParameter("name");
        String firstName = request.getParameter("firstName");
        String email = request.getParameter("email");
        String password = request.getParameter("password");
        String confirmation = request.getParameter("confirmation");
        String phone = request.getParameter("phone");
        String address = request.getParameter("address");

        System.out.println("Ajout d'un utilisateur:"+name+","+firstName+","+email+","+password+","+confirmation);


        EntityManagerFactory emf = Persistence.createEntityManagerFactory("persistenceUnit");
        EntityManager em = emf.createEntityManager();
        em.getTransaction().begin();

        User u = new User();

        u.setName(name);
        u.setFirstName(firstName);
        u.setPassword(password);
        u.setEmail(email);
        u.setAddress(address);
        u.setPhone(phone);
        em.persist(u);
        em.getTransaction().commit();



        this.getServletContext().getRequestDispatcher("/Home.jsp").forward(request, response);

    }
}

<persistence-unit name="persistenceUnit">
    **<provider>org.hibernate.jpa.HibernatePersistenceProvider</provider>**
    <class>Entities.User</class>