jpa - javax.ejb.CreateException : Could not create stateless EJB with glassfish and boneCP on intellij-idea

Question

我最近开始通过一个简单的网络应用程序在 intellij idea 上使用 Glassfish 和 boneCP，但是有一个我无法理解的错误。我相信我遵循了教程中的所有步骤。

我的模型是这样的

@Entity
public class Song implements Serializable {

@Id
private String id;
private String title;
private LocalDate lastPlayed;
private int playCount;

public Song() {
    title = "Chant sans titre";
    id = generateId(title);
    lastPlayed = LocalDate.ofEpochDay(0);
    playCount = 0;
}

EJB

@Stateless
public class SongDAO {

@PersistenceUnit(unitName = "statisthira_song")
private EntityManager em;

public void create(Song song){
    try {
        em.persist(song); }  catch (Exception e) { e.printStackTrace(); }
} 

小服务程序

@WebServlet(urlPatterns = "/new-song")
public class NewSongActionBean extends HttpServlet {

@EJB
SongDAO dao;

@Override
protected void doGet(HttpServletRequest request, HttpServletResponse response) throws ServletException, IOException {
    Song song = new Song();
        song.setTitle("This is not a Test - Toby Mac");
        song.setId(song.generateId(song.getTitle()));
    dao.create(song);

    this.getServletContext().getRequestDispatcher("/WEB-INF/newsong.jsp").forward(request, response);
}
}

我在 META-INF 下的 persistence.xml 文件

<?xml version="1.0" encoding="UTF-8"?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence" version="2.0"
         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_2_0.xsd">

<persistence-unit name="statisthira_song" transaction-type="JTA">
    <provider>org.eclipse.persistence.jpa.PersistenceProvider</provider>
    <jta-data-source>jdbc/bonecp_resource</jta-data-source>
    <class>statis.hira.model.Song</class>
</persistence-unit>

</persistence>

服务器运行没有任何问题，当我用 ping 检查 jdbc 连接池时，它成功了。但是当我尝试访问 url "/new-song"时，我收到了这个错误信息

HTTP Status 500 - Internal Server Error

type Exception report

message Internal Server Error

description The server encountered an internal error that prevented it from fulfilling this request.

exception javax.ejb.EJBException: javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB

这是堆栈跟踪的示例

javax.ejb.EJBException: javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB
at com.sun.ejb.containers.StatelessSessionContainer._getContext(StatelessSessionContainer.java:435)
at com.sun.ejb.containers.BaseContainer.getContext(BaseContainer.java:2579)
at com.sun.ejb.containers.BaseContainer.preInvoke(BaseContainer.java:1971)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandler.invoke(EJBLocalObjectInvocationHandler.java:210)
at com.sun.ejb.containers.EJBLocalObjectInvocationHandlerDelegate.invoke(EJBLocalObjectInvocationHandlerDelegate.java:88)
at com.sun.proxy.$Proxy194.create(Unknown Source)
at statis.hira.dao.__EJB31_Generated__SongDAO__Intf____Bean__.create(Unknown Source)
at statis.hira.servlets.NewSongActionBean.doGet(NewSongActionBean.java:26)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:687)
at javax.servlet.http.HttpServlet.service(HttpServlet.java:790)
at org.apache.catalina.core.StandardWrapper.service(StandardWrapper.java:1682)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:318)
at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:160)
at org.apache.catalina.core.StandardPipeline.doInvoke(StandardPipeline.java:734)
at org.apache.catalina.core.StandardPipeline.invoke(StandardPipeline.java:673)
at com.sun.enterprise.web.WebPipeline.invoke(WebPipeline.java:99)
at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:174)
at org.apache.catalina.connector.CoyoteAdapter.doService(CoyoteAdapter.java:416)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:283)
at com.sun.enterprise.v3.services.impl.ContainerMapper$HttpHandlerCallable.call(ContainerMapper.java:459)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:167)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:206)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:180)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:235)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:283)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:200)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:132)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:111)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:536)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:112)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:117)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:56)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:137)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:591)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:571)
at java.lang.Thread.run(Thread.java:745)
Caused by: javax.ejb.EJBException: javax.ejb.CreateException: Could not create stateless EJB
at com.sun.ejb.containers.StatelessSessionContainer$SessionContextFactory.create(StatelessSessionContainer.java:700)
at com.sun.ejb.containers.util.pool.NonBlockingPool.getObject(NonBlockingPool.java:246)
at com.sun.ejb.containers.StatelessSessionContainer._getContext(StatelessSessionContainer.java:430)
... 37 more
Caused by: javax.ejb.CreateException: Could not create stateless EJB
at com.sun.ejb.containers.StatelessSessionContainer.createStatelessEJB(StatelessSessionContainer.java:514)
at com.sun.ejb.containers.StatelessSessionContainer.access$000(StatelessSessionContainer.java:97)
at com.sun.ejb.containers.StatelessSessionContainer$SessionContextFactory.create(StatelessSessionContainer.java:698)
... 39 more
Caused by: java.lang.IllegalStateException: Exception attempting to inject Env-Prop: statis.hira.dao.SongDAO/em@Field-Injectable Resource. Class name = statis.hira.dao.SongDAO Field name=em@java.lang.String@@@ into class statis.hira.dao.SongDAO: Can not set javax.persistence.EntityManager field statis.hira.dao.SongDAO.em to com.sun.enterprise.container.common.impl.EntityManagerFactoryWrapper
at org.glassfish.weld.services.InjectionServicesImpl.aroundInject(InjectionServicesImpl.java:175)
at org.jboss.weld.injection.InjectionContextImpl.run(InjectionContextImpl.java:46)
at org.jboss.weld.injection.producer.DefaultInjector.inject(DefaultInjector.java:73)
at org.jboss.weld.injection.producer.StatelessSessionBeanInjector.inject(StatelessSessionBeanInjector.java:60)
at org.jboss.weld.injection.producer.ejb.SessionBeanInjectionTarget.inject(SessionBeanInjectionTarget.java:140)
at org.glassfish.weld.services.JCDIServiceImpl.injectEJBInstance(JCDIServiceImpl.java:257)
at com.sun.ejb.containers.BaseContainer.injectEjbInstance(BaseContainer.java:1748)
at com.sun.ejb.containers.StatelessSessionContainer.createStatelessEJB(StatelessSessionContainer.java:475)
... 41 more
Caused by: com.sun.enterprise.container.common.spi.util.InjectionException: Exception attempting to inject Env-Prop: statis.hira.dao.SongDAO/em@Field-Injectable Resource. Class name = statis.hira.dao.SongDAO Field name=em@java.lang.String@@@ into class statis.hira.dao.SongDAO: Can not set javax.persistence.EntityManager field statis.hira.dao.SongDAO.em to com.sun.enterprise.container.common.impl.EntityManagerFactoryWrapper
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:740)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.inject(InjectionManagerImpl.java:507)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.injectInstance(InjectionManagerImpl.java:170)
at org.glassfish.weld.services.InjectionServicesImpl.aroundInject(InjectionServicesImpl.java:165)
... 48 more
Caused by: java.lang.IllegalArgumentException: Can not set javax.persistence.EntityManager field statis.hira.dao.SongDAO.em to com.sun.enterprise.container.common.impl.EntityManagerFactoryWrapper
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:167)
at sun.reflect.UnsafeFieldAccessorImpl.throwSetIllegalArgumentException(UnsafeFieldAccessorImpl.java:171)
at sun.reflect.UnsafeObjectFieldAccessorImpl.set(UnsafeObjectFieldAccessorImpl.java:81)
at java.lang.reflect.Field.set(Field.java:764)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:688)
... 51 more

Answer 1

你应该从

@PersistenceUnit(unitName = "statisthira_song")

到

@PersistenceContext(name= "statisthira_song")

@PersistenceUnit 用于注入(inject) EntityManagerFactory 和 @PersistenceContext 用于注入(inject)EntityManager