WorkManager in JBOSS 5.1.0

We can implement jboss workmanager by below code.. It worked perfectly in jboss 5.1.0   import javax.management.MBeanServerConnection;
import javax.management.MBeanServerInvocationHandler;
import javax.management.ObjectName;
import javax.naming.Context;
import javax.naming.InitialContext;
import javax.resource.spi.work.WorkManager;

import org.jboss.resource.work.JBossWorkManagerMBean; public class JBWorkManager {

public static WorkManager getWorkManager() {

     WorkManager workmanager = null;
     Context context = null;
     Properties properties = new Properties();
     properties.put(Context.INITIAL_CONTEXT_FACTORY, "org.jnp.interfaces.NamingContextFactory");
    properties.put(Context.URL_PKG_PREFIXES, "org.jboss.naming:org.jnp.interfaces");
    properties.put(Context.PROVIDER_URL, "jnp://localhost:1099");

    try {
          context= new InitialContext(properties);
          MBeanServerConnection mconn = (MBeanServerConnection)  context.lookup("jmx/rmi/RMIAdaptor");
         ObjectName objectName = new ObjectName("jboss.jca:service=WorkManager");
         JBossWorkManagerMBean jwm = (JBossWorkManagerMBean)
MBeanServerInvocationHandler.newProxyInstance(mconn,objectName,JBossWorkManagerMBean.class,false);
         workmanager = jwm.getInstance();
   } catch (Exception ex) {

ex.printStackTrace();
}

return workmanager;
}

}