3 Replies Latest reply on Oct 25, 2004 9:30 PM by Bill Burke

    EntityManager and hbm.xml mapping files

    Igor Fedorenko Newbie

      I already have few Hibernate persitent classes (i.e. classes that have corresponding *.hbm.xml mapping files). I really want to start using these classes with EJB3 stateless session beans and EntityManager today and migrate to EJB3 entity bean annotations gradually over time. Another reason I want to use hbm.xml for some of my persistent classes is the lack of CLOB/BLOB support and probably other high-end Hibernate features in the current EJB3 spec draft. Does this sound like reasonable requirements? I've put together little prototype that allows me to use hbm.xml files to define entity beans and it looks promising but I am how that alligns with overall EJB3 directions.

        • 1. Re: EntityManager and hbm.xml mapping files
          Bill Burke Master

          I guess I did not explain my usage scenario properly. I already have classes and corresponding *.hbm.xml files (actually, my classes have xdcolet tags, but that's not too important). I want to start writing new EJB3 stateless session beans, but do not want to remap all my entities with EJB3 annotations right now.

          The prototype that I have is close to what are suggesting. Bascially, it adds all hbm.xml files from EJB3 module to Hibernate configuration used internally by EntityManager. As far as my session beans are concerned, they are dealing with EntityManager and EJB3 entity beans, and I can gradually replace hbm files with annotations "some time later" :-)

          This also allows me to use EntityManager for things that are not possible yet to define using annotations (eg. CLOBs).

          • 2. Re: Nukes compatibility to JBoss upgrade path
            Bill Burke Master

            ok, had some time today to have a look again...

            The getNext() is now done in the AbstractInterceptor.Invoke()...
            so I just deleted all the lines in the LifecycleInterceptor.

            Some strange things happen now and then wenn in the LifeCycle the invoke() is called with type "invoke"... debug showed that "invoke, getLanguage" is called on the MBeanAttributeInterceptor, which then throws an Exception because it does not understand the command.
            I just catched this exception and returned null in LifeCycle.invoke. It should not be done this way, but now nukes deploys, at least...

            Next problem ist a nullpointer:

            15:02:19,484 ERROR [Engine] StandardWrapperValve[NukeServlet]: Servlet.service()
            for servlet NukeServlet threw exception
            java.lang.NullPointerException: charsetName
            at java.lang.String.(String.java:410)
            at java.lang.String.(String.java:440)
            at org.apache.coyote.tomcat5.CoyoteRequest.setCharacterEncoding(CoyoteRe
            quest.java:1523)
            at org.apache.coyote.tomcat5.CoyoteRequestFacade.setCharacterEncoding(Co
            yoteRequestFacade.java:240)
            at org.jboss.nukes.servlet.ParameterEncodingFilter.doFilter(ParameterEnc
            odingFilter.java:58)


            LifeCycleInterceptor:


            public class LifeCycleInterceptor
             extends AbstractInterceptor {
            
             // Attributes ----------------------------------------------------
            
             private Logger log;
            
            
             // Constructors --------------------------------------------------
            
             public LifeCycleInterceptor() {
             super();
             this.log = Logger.getLogger(this.getClass());
             log.debug("called no-args-constructor");
             }
            
             public LifeCycleInterceptor(MBeanInfo info, MBeanInvoker invoker) {
             log.debug("called constructor:LifeCycleInterceptor(MBeanInfo info, MBeanInvoker invoker)");
             this.name=info.getClassName();
             this.log = Logger.getLogger(info.getClassName());
             }
            
             // Public --------------------------------------------------------
            
             public Object invoke(Invocation invocation) throws Exception,Throwable {
             this.name=invocation.getInvoker().getMetaData().getClassName();
             this.log = Logger.getLogger(invocation.getInvoker().getMetaData().getClassName());
             log.debug("LifeCycleInterceptor::invoke();invocation.getType()"+invocation.getType());
             log.debug("LifeCycleInterceptor::invoke();invocation.getName()"+invocation.getName());
             try {
             if (invocation.getType() == Invocation.OP_INVOKE &&
             // changed here
             //if (invocation.getInvocationType() == Invocation.OPERATION &&
             invocation.getSignature() != null &&
             invocation.getSignature().length == 0) {
             if ("create".equals(invocation.getName())) {
             log.info("Creating");
             create(invocation);
             log.info("Created");
             return null;
             } else if ("start".equals(invocation.getName())) {
             log.info("Starting");
             start(invocation);
             log.info("Started");
             return null;
             } else if ("stop".equals(invocation.getName())) {
             log.info("Stopping");
             stop(invocation);
             log.info("Stopped");
             return null;
             } else if ("destroy".equals(invocation.getName())) {
             log.info("Destroying");
             destroy(invocation);
             log.info("Destroyed");
             return null;
             }
             }
             }
             catch (Throwable e) {
             log.error(e.getMessage());
             log.debug("invocationtype:"+invocation.getType());
             throw new Exception(e);
             }
             //getNext().invoke;
             log.debug("calling interceptor.invoke()");
             try {
             return invocation.invoke();
             } catch (Throwable e) {// changed here
             log.debug("catched exception "+e.getMessage());
             return null;
             }
             }
            
             // Private -------------------------------------------------------
            
             private void setState(int nextState, MBeanInvoker invoker) throws Exception {
             // if state changes
             if (getState(invoker) != nextState) {
             try {
             // update the state
             invoker.setAttribute(new Attribute("State", new Integer(nextState)));
             } catch (MBeanException e) {
             log.error("Cannot send state changed notification", e);
             }
             }
             }
            
             private int getState(MBeanInvoker invoker) throws Exception {
             return ((Integer) invoker.getAttribute("State")).intValue();
             }
            
             private void create(Invocation invocation) throws Exception {
             setState(ServiceMBean.CREATED,invocation.getInvoker());
             }
            
             private void start(Invocation invocation) throws Exception {
             int state = getState(invocation.getInvoker());
             if (state == ServiceMBean.STARTING || state == ServiceMBean.STARTED) {
             return;
             }
             setState(ServiceMBean.STARTING,invocation.getInvoker());
             transition(invocation, ServiceMBean.STARTED, ServiceMBean.FAILED);
             }
            
             private void stop(Invocation invocation) throws Exception {
             if (getState(invocation.getInvoker()) != ServiceMBean.STARTED) {
             return;
             }
             setState(ServiceMBean.STOPPING,invocation.getInvoker());
             transition(invocation, ServiceMBean.STOPPED, ServiceMBean.FAILED);
             }
            
             private void destroy(Invocation invocation) throws Exception, Throwable {
             int state = getState(invocation.getInvoker());
             if (state == ServiceMBean.DESTROYED) {
             return;
             }
             if (state == ServiceMBean.STOPPED) {
             invocation.getInvoker().invoke("stop", new Object[0], new String[0]);
             }
             setState(ServiceMBean.DESTROYED,invocation.getInvoker());
             }
            
             private void transition(Invocation invocation, int success, int failure) throws Exception {
             try {
             setState(success,invocation.getInvoker());
             } catch (Throwable e) {
             setState(failure,invocation.getInvoker());
             throw new Exception(e);
             }
             }
            }


            • 3. Re: EntityManager and hbm.xml mapping files
              Igor Fedorenko Newbie

              I guess I did not explain my usage scenario properly. I already have classes and corresponding *.hbm.xml files (actually, my classes have xdcolet tags, but that's not too important). I want to start writing new EJB3 stateless session beans, but do not want to remap all my entities with EJB3 annotations right now.

              The prototype that I have is close to what are suggesting. Bascially, it adds all hbm.xml files from EJB3 module to Hibernate configuration used internally by EntityManager. As far as my session beans are concerned, they are dealing with EntityManager and EJB3 entity beans, and I can gradually replace hbm files with annotations "some time later" :-)

              This also allows me to use EntityManager for things that are not possible yet to define using annotations (eg. CLOBs).