PersistenceContext EntityManager (JPA) - database

Question

I am creating a Java EE application using jpa.
The problem in #PersistenceContext(unitName = "airline") when i comment this line it give me error null_pointer_exception and when put it getting the following error when the code is run on server.
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Severe: Exception while invoking class org.glassfish.persistence.jpa.JPADeployer prepare method
Severe: java.lang.RuntimeException: Could not resolve a persistence unit corresponding to the persistence-context-ref-name [com.airline.service.PassengerService/entityManager] in the scope of the module called [FlightPassengersJPA]. Please verify your application.
at com.sun.enterprise.deployment.BundleDescriptor.findReferencedPUViaEMRef(BundleDescriptor.java:731)
at com.sun.enterprise.deployment.BundleDescriptor.findReferencedPUsViaPCRefs(BundleDescriptor.java:719)
at org.glassfish.web.deployment.descriptor.WebBundleDescriptorImpl.findReferencedPUs(WebBundleDescriptorImpl.java:1037)
at org.glassfish.persistence.jpa.JPADeployer.createEMFs(JPADeployer.java:186)
at org.glassfish.persistence.jpa.JPADeployer.prepare(JPADeployer.java:168)
at com.sun.enterprise.v3.server.ApplicationLifecycle.prepareModule(ApplicationLifecycle.java:925)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:434)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:539)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:535)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:534)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:565)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:557)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:556)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1464)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1300(CommandRunnerImpl.java:109)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1846)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1722)
at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:534)
at com.sun.enterprise.v3.admin.AdminAdapter.onMissingResource(AdminAdapter.java:224)
at org.glassfish.grizzly.http.server.StaticHttpHandlerBase.service(StaticHttpHandlerBase.java:189)
at com.sun.enterprise.v3.services.impl.ContainerMapper$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:748)
Severe: Exception while preparing the app
Severe: Exception during lifecycle processing
java.lang.RuntimeException: Could not resolve a persistence unit corresponding to the persistence-context-ref-name [com.airline.service.PassengerService/entityManager] in the scope of the module called [FlightPassengersJPA]. Please verify your application.
at com.sun.enterprise.deployment.BundleDescriptor.findReferencedPUViaEMRef(BundleDescriptor.java:731)
at com.sun.enterprise.deployment.BundleDescriptor.findReferencedPUsViaPCRefs(BundleDescriptor.java:719)
at org.glassfish.web.deployment.descriptor.WebBundleDescriptorImpl.findReferencedPUs(WebBundleDescriptorImpl.java:1037)
at org.glassfish.persistence.jpa.JPADeployer.createEMFs(JPADeployer.java:186)
at org.glassfish.persistence.jpa.JPADeployer.prepare(JPADeployer.java:168)
at com.sun.enterprise.v3.server.ApplicationLifecycle.prepareModule(ApplicationLifecycle.java:925)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:434)
at com.sun.enterprise.v3.server.ApplicationLifecycle.deploy(ApplicationLifecycle.java:219)
at org.glassfish.deployment.admin.DeployCommand.execute(DeployCommand.java:491)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:539)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2$1.run(CommandRunnerImpl.java:535)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$2.execute(CommandRunnerImpl.java:534)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:565)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$3.run(CommandRunnerImpl.java:557)
at java.security.AccessController.doPrivileged(Native Method)
at javax.security.auth.Subject.doAs(Subject.java:360)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:556)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.doCommand(CommandRunnerImpl.java:1464)
at com.sun.enterprise.v3.admin.CommandRunnerImpl.access$1300(CommandRunnerImpl.java:109)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1846)
at com.sun.enterprise.v3.admin.CommandRunnerImpl$ExecutionContext.execute(CommandRunnerImpl.java:1722)
at com.sun.enterprise.v3.admin.AdminAdapter.doCommand(AdminAdapter.java:534)
at com.sun.enterprise.v3.admin.AdminAdapter.onMissingResource(AdminAdapter.java:224)
at org.glassfish.grizzly.http.server.StaticHttpHandlerBase.service(StaticHttpHandlerBase.java:189)
at com.sun.enterprise.v3.services.impl.ContainerMapper$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:748)
Severe: Exception while preparing the app : Could not resolve a persistence unit corresponding to the persistence-context-ref-name [com.airline.service.PassengerService/entityManager] in the scope of the module called [FlightPassengersJPA]. Please verify your application.
and my code :
AddPassenger.java
package com.airline.controllers;
import com.airline.models.FlightClass;
import com.airline.models.Gender;
import com.airline.models.Passenger;
import com.airline.service.PassengerService;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.Calendar;
import java.util.Date;
import javax.ejb.EJB;
import javax.servlet.ServletException;
import javax.servlet.annotation.WebServlet;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
#WebServlet(name = "AddPassenger", urlPatterns = {"/AddPassenger"})
public class AddPassenger extends HttpServlet {
#EJB
private PassengerService passengerService;
#Override
protected void doGet(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
Passenger passenger = new Passenger();
passenger.setFirstName("Loai");
passenger.setLastName("Amr");
Calendar cal = Calendar.getInstance();
cal.set(Calendar.YEAR, 1996);
cal.set(Calendar.MONTH, 9);
cal.set(Calendar.DAY_OF_MONTH, 30);
Date dob = cal.getTime();
passenger.setDob(dob);
passenger.setGender(Gender.Male);
passenger.setFlightClass(FlightClass.Couch);
passengerService.addPassenger(passenger);
System.out.println("First name : " + passenger.getFirstName());
}
#Override
protected void doPost(HttpServletRequest request, HttpServletResponse response)
throws ServletException, IOException {
processRequest(request, response);
}
#Override
public String getServletInfo() {
return "Short description";
}// </editor-fold>
}
and class PassengerService :
package com.airline.service;
import com.airline.models.Passenger;
import javax.ejb.EJB;
import javax.ejb.LocalBean;
import javax.ejb.Stateless;
import javax.persistence.EntityManager;
import javax.persistence.PersistenceContext;
import javax.persistence.PersistenceContextType;
#Stateless
#LocalBean
public class PassengerService {
public PassengerService() {
}
#PersistenceContext(unitName = "airline")
private EntityManager entityManager;
public void addPassenger(Passenger passenger) {
entityManager.persist(passenger);
System.out.println("Done");
}
}
and persistence.xml
<?xml version="1.0" encoding="UTF-8"?>
<persistence version="2.1" xmlns="http://xmlns.jcp.org/xml/ns/persistence" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://xmlns.jcp.org/xml/ns/persistence http://xmlns.jcp.org/xml/ns/persistence/persistence_2_1.xsd">
<persistence-unit name="FlightPassengersJPAPU" transaction-type="JTA">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<jta-data-source>jdbc/airline</jta-data-source>
<exclude-unlisted-classes>false</exclude-unlisted-classes>
<properties>
<property name="javax.persistence.schema-generation.database.action" value="create"/>
</properties>
</persistence-unit>
</persistence>

Answer 1

You need to define your persistence-unit in a file named persistence.xml. This should reside as resource in META-INF.
An example for that you can see in:
persistence.xml... The datasources you see there is defined in the configuration of the wildfly as you can see it in standalone.xml
In a similar way I think you have do define the datasource in glassfish.