title: using JPA2 for an entity update
body: <p>I'm not really used to JPA... so this is more like a basic question</p>
  
  <p>I use JPA2 - (not hibernate)</p>
  
  <p>I have this function, and I want to make an update on my </p>
  
  <pre><code>@RequestScoped // (this is javax.faces.bean.RequestScoped)
  @Stafeful // (this is javax.ejb.Stateful)
  public class MyProvider {
  
  
      @Inject
      private EntityManager entityManager;
  
      /* some variables and getters and setters */
  
      public void setLocked(Long id, boolean locked) {
          entityManager.getTransaction().begin();
          user = userProvider.findUserByID(id);
          user.setLocked(locked);
          entityManager.persist(user);
  
          // i also tried it with refresh instead of persist
          entityManager.refresh(user);
  
          entityManager.getTransaction().commit();
      }
  }
  </code></pre>
  
  <p>but i get this error at this point
   entityManager.getTransaction().begin();</p>
  
  <pre><code>java.lang.IllegalStateException: A JTA EntityManager cannot use getTransaction()
      org.hibernate.ejb.AbstractEntityManagerImpl.getTransaction(AbstractEntityManagerImpl.java:996)
      org.jboss.as.jpa.container.AbstractEntityManager.getTransaction(AbstractEntityManager.java:498)
      sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      java.lang.reflect.Method.invoke(Method.java:601)
      org.jboss.weld.util.reflection.SecureReflections$13.work(SecureReflections.java:264)
      org.jboss.weld.util.reflection.SecureReflectionAccess.run(SecureReflectionAccess.java:52)
      org.jboss.weld.util.reflection.SecureReflectionAccess.runAsInvocation(SecureReflectionAccess.java:137)
      org.jboss.weld.util.reflection.SecureReflections.invoke(SecureReflections.java:260)
      org.jboss.weld.bean.builtin.CallableMethodHandler.invoke(CallableMethodHandler.java:51)
      org.jboss.weld.bean.proxy.EnterpriseTargetBeanInstance.invoke(EnterpriseTargetBeanInstance.java:56)
      org.jboss.weld.bean.proxy.ProxyMethodHandler.invoke(ProxyMethodHandler.java:105)
      org.jboss.weldx.persistence.EntityManager$-1570536921$Proxy$_$$_Weld$Proxy$.getTransaction(EntityManager$-1570536921$Proxy$_$$_Weld$Proxy$.java)
      de.demoapp.controller.UserController.setLocked(UserController.java:452)
      de.demoapp.controller.UserController.lock(UserController.java:721)
      sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
      sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:57)
      sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
      java.lang.reflect.Method.invoke(Method.java:601)
      org.apache.el.parser.AstValue.invoke(AstValue.java:262)
      org.apache.el.MethodExpressionImpl.invoke(MethodExpressionImpl.java:278)
      org.jboss.weld.util.el.ForwardingMethodExpression.invoke(ForwardingMethodExpression.java:39)
      org.jboss.weld.el.WeldMethodExpression.invoke(WeldMethodExpression.java:50)
      com.sun.faces.facelets.el.TagMethodExpression.invoke(TagMethodExpression.java:105)
      javax.faces.component.MethodBindingMethodExpressionAdapter.invoke(MethodBindingMethodExpressionAdapter.java:88)
      com.sun.faces.application.ActionListenerImpl.processAction(ActionListenerImpl.java:102)
      javax.faces.component.UICommand.broadcast(UICommand.java:315)
      javax.faces.component.UIData.broadcast(UIData.java:1093)
      javax.faces.component.UIViewRoot.broadcastEvents(UIViewRoot.java:794)
      javax.faces.component.UIViewRoot.processApplication(UIViewRoot.java:1259)
      com.sun.faces.lifecycle.InvokeApplicationPhase.execute(InvokeApplicationPhase.java:81)
      com.sun.faces.lifecycle.Phase.doPhase(Phase.java:101)
      com.sun.faces.lifecycle.LifecycleImpl.execute(LifecycleImpl.java:118)
      javax.faces.webapp.FacesServlet.service(FacesServlet.java:593)
      org.jboss.weld.servlet.ConversationPropagationFilter.doFilter(ConversationPropagationFilter.java:62)
  </code></pre>
  
  <p>I have also read <a href="https://stackoverflow.com/questions/3592075/howto-implement-update-in-hibernate-jpa2">this</a> article - but it doesn't really help, it still throws:   <code>javax.persistence.TransactionRequiredException: no transaction is in progress</code></p>
  
  <p>I'm not sure if I do something essential wrong...</p>