javax.naming.NameNotFoundException：找不到MyBean＃MyBean

Question

I have a multi module maven project which contains a jar module (models), two EJB modules (repository, service) and a web module. The first thing that may cause the problem is that I don't know in which EJB module should I place the persistence.xml file.

It looks like this:

<?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>

I've also tried placing it in both repository and service modules (src/main/resources/META-INF) but I'm still getting this exception:

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)

Any suggestions?

UPDATE

Here's a part of the servlet:

@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

You don't need any EJBs in persistence.xml, this file is JPA configuration file where you configure your persistence layer. Here are the steps you should do (I did not delve deeply into Glassfish configuration, because you have to create a MySQL JDBC data source called jdbc/MySQL, and persistence unit reference into into EJBs, for that please consult Glassfish documentation).

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;

and then in EJB methods use

entityManager.persist(myJpaEntity);

Another thing I've spotted: in persistence.xml you are using JPA 1.0. Most modern application servers and Spring support JPA 2.0 or event better 2.1 usage that has improved API and is definitively a better choice (I have added persistence 2.0 configuration here).