Question

我有一个多模块maven项目，它包含一个jar模块（模型），两个EJB模块（存储库，服务）和一个Web模块。可能导致问题的第一件事是我不知道应该在哪个EJB模块中放置persistence.xml文件。

看起来像这样：

<?xml version="1.0" encoding="UTF-8" ?>
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
 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_1_0.xsd" version="1.0">

   <persistence-unit name="jthrdb">

        <jta-data-source>MySQL</jta-data-source>

   </persistence-unit>

</persistence>

我也尝试将它放在存储库和服务模块（src / main / resources / META-INF）中，但我仍然得到这个例外：

javax.naming.NameNotFoundException: MyBean#MyBean not found
at com.sun.enterprise.naming.impl.TransientContext.doLookup(TransientContext.java:237)
at com.sun.enterprise.naming.impl.TransientContext.lookup(TransientContext.java:204)
at com.sun.enterprise.naming.impl.SerialContextProviderImpl.lookup(SerialContextProviderImpl.java:66)
at com.sun.enterprise.naming.impl.LocalSerialContextProviderImpl.lookup(LocalSerialContextProviderImpl.java:114)
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:478)
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:438)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at com.sun.ejb.EjbNamingReferenceManagerImpl.resolveEjbReference(EjbNamingReferenceManagerImpl.java:183)
at com.sun.enterprise.container.common.impl.ComponentEnvManagerImpl$EjbReferenceProxy.create(ComponentEnvManagerImpl.java:1143)
at com.sun.enterprise.naming.impl.GlassfishNamingManagerImpl.lookup(GlassfishNamingManagerImpl.java:745)
at com.sun.enterprise.naming.impl.GlassfishNamingManagerImpl.lookup(GlassfishNamingManagerImpl.java:715)
at com.sun.enterprise.naming.impl.JavaURLContext.lookup(JavaURLContext.java:159)
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:471)
at com.sun.enterprise.naming.impl.SerialContext.lookup(SerialContext.java:438)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at javax.naming.InitialContext.lookup(InitialContext.java:411)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl._inject(InjectionManagerImpl.java:613)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.inject(InjectionManagerImpl.java:484)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.injectInstance(InjectionManagerImpl.java:141)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.injectInstance(InjectionManagerImpl.java:127)
at com.sun.enterprise.container.common.impl.util.InjectionManagerImpl.createManagedObject(InjectionManagerImpl.java:324)
at com.sun.enterprise.web.WebContainer.createServletInstance(WebContainer.java:983)
at com.sun.enterprise.web.WebModule.createServletInstance(WebModule.java:2130)
at org.apache.catalina.core.StandardWrapper.loadServlet(StandardWrapper.java:1404)
at org.apache.catalina.core.StandardWrapper.allocate(StandardWrapper.java:1211)
at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:237)
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:357)
at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:260)
at com.sun.enterprise.v3.services.impl.ContainerMapper.service(ContainerMapper.java:188)
at org.glassfish.grizzly.http.server.HttpHandler.runService(HttpHandler.java:191)
at org.glassfish.grizzly.http.server.HttpHandler.doHandle(HttpHandler.java:168)
at org.glassfish.grizzly.http.server.HttpServerFilter.handleRead(HttpServerFilter.java:189)
at org.glassfish.grizzly.filterchain.ExecutorResolver$9.execute(ExecutorResolver.java:119)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeFilter(DefaultFilterChain.java:288)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.executeChainPart(DefaultFilterChain.java:206)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.execute(DefaultFilterChain.java:136)
at org.glassfish.grizzly.filterchain.DefaultFilterChain.process(DefaultFilterChain.java:114)
at org.glassfish.grizzly.ProcessorExecutor.execute(ProcessorExecutor.java:77)
at org.glassfish.grizzly.nio.transport.TCPNIOTransport.fireIOEvent(TCPNIOTransport.java:838)
at org.glassfish.grizzly.strategies.AbstractIOStrategy.fireIOEvent(AbstractIOStrategy.java:113)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.run0(WorkerThreadIOStrategy.java:115)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy.access$100(WorkerThreadIOStrategy.java:55)
at org.glassfish.grizzly.strategies.WorkerThreadIOStrategy$WorkerThreadRunnable.run(WorkerThreadIOStrategy.java:135)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.doWork(AbstractThreadPool.java:564)
at org.glassfish.grizzly.threadpool.AbstractThreadPool$Worker.run(AbstractThreadPool.java:544)
at java.lang.Thread.run(Thread.java:745)

有什么建议吗？

更新

这是servlet的一部分：

@WebServlet("/MyServlet")
public class MyServlet extends HttpServlet {
private static final long serialVersionUID = 1L;

@EJB
private CandidateBean bean;

/**
 * @see HttpServlet#HttpServlet()
 */
public MyServlet() {
    super();
    // TODO Auto-generated constructor stub
}

/**
 * @see HttpServlet#doGet(HttpServletRequest request, HttpServletResponse
 *      response)
 */
@Override
protected void doGet(HttpServletRequest request,
        HttpServletResponse response) throws ServletException, IOException {
    PrintWriter out = response.getWriter();
    Candidate temp = new Candidate();
    temp.setFirstName("Pos");
    // bean.insert(temp);
    out.println("<html>");
    out.println("<body>");
    out.println("<h1>" + bean.saySomething() + "</h1>");
    out.println("</body>");
    out.println("</html>");
}
}

Answer 1

您在persistence.xml中不需要任何EJB，此文件是JPA配置文件，您可以在其中配置持久层。以下是您应该执行的步骤（我没有深入研究Glassfish配置，因为您必须创建一个名为jdbc / MySQL的MySQL JDBC数据源，并将持久性单元引用到EJB中，请参阅Glassfish文档）。

的persistence.xml

<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.0" xmlns="http://java.sun.com/xml/ns/persistence" 
    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="jthrdb" transaction-type="JTA">
        <jta-data-source>jdbc/MySQL</jta-data-source>
        <class>com.test.MyJpaEntity</class>
        </persistence-unit>
   </persistence>

@PersistenceContext(unitName = "jthrdb")
private EntityManager entityManager;

然后在EJB方法中使用

entityManager.persist(myJpaEntity);

我发现的另一件事：在persistence.xml中你使用的是JPA 1.0。大多数现代应用程序服务器和Spring支持JPA 2.0或事件更好2.1使用已经改进了API，并且绝对是更好的选择（我在这里添加了持久性2.0配置）。

javax.naming.NameNotFoundException：找不到MyBean＃MyBean

1 个答案: