Client Reconnection Interceptor

See this JIRA Issue

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* Lesser General Public License for more details.
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package org.jboss.mq.server;

import java.util.Iterator;

import javax.jms.InvalidClientIDException;
import javax.jms.JMSException;

import org.jboss.logging.Logger;
import org.jboss.mq.ConnectionToken;
/**
 * The JMS spec does not let a second client with the same clientID connect to
 * the server.  The second client gets an InvalidClientIDException exception.
 * This interceptor modifies the server so that the first client gets
 * disconnected and then the second client can connect successfully.
 * 
 * Currently it only works if the client id is set by the client using the
 * setClient method call.
 *
 * @author <a href="mailto:hchirino@jboss.org">Hiram Chirino</a>
 */
public class ClientReconnectInterceptor extends JMSServerInterceptorSupport {

     static protected Logger log =
          Logger.getLogger(ClientReconnectInterceptor.class);

     private JMSDestinationManager destinationManager;
     private JMSDestinationManager getDestinationManager() {
          if(destinationManager!=null)
               return destinationManager;
               
          JMSServerInterceptor interceptor = getNext(); 
          while( ! (interceptor instanceof JMSDestinationManager) ) 
               interceptor = getNext();
          destinationManager = (JMSDestinationManager)interceptor;
          return destinationManager;
     }
     
     private ConnectionToken findConnectionTokenFor(String clientID) {
          Iterator iterator = getDestinationManager().clientConsumers.keySet().iterator();
          while (iterator.hasNext()) {
               ConnectionToken dc = (ConnectionToken) iterator.next();
               if( dc.getClientID().equals(clientID))
                    return dc;
          }
          return null;
     }

     /**
      * @see org.jboss.mq.server.JMSServerInterceptor#checkID(java.lang.String)
      */
     public void checkID(String ID) throws JMSException {
          try {
               super.checkID(ID);
          } catch (InvalidClientIDException e) {
               ConnectionToken dc = findConnectionTokenFor(ID);
               // The InvalidClientIDException could have been thrown
               // due to another reason besides a double client connect.
               if( dc == null ) 
                    throw e;
                    
               // try to disconnect the previous client
               try {
                    super.connectionClosing(dc);
               } catch (Throwable e2) {
                    // Log it in case we ever care to find out the details.
                    log.trace("Disconnect of previously connected client caused an error:",e);
               }
               
               // try it again...
               super.checkID(ID);                    
          }
     }
}