runtime/org.argeo.slc.server/src/main/java/org/argeo/slc/web/mvc/WebSlcEventListenerRegister.java

   1 package org.argeo.slc.web.mvc;
   2
   3 import java.io.Serializable;
   4 import java.util.List;
   5 import java.util.Vector;
   6
   7 import org.apache.commons.logging.Log;
   8 import org.apache.commons.logging.LogFactory;
   9 import org.argeo.slc.SlcException;
  10 import org.argeo.slc.msg.event.SlcEvent;
  11 import org.argeo.slc.msg.event.SlcEventListener;
  12 import org.argeo.slc.msg.event.SlcEventListenerDescriptor;
  13 import org.argeo.slc.msg.event.SlcEventListenerRegister;
  14 import org.springframework.web.context.request.RequestContextHolder;
  15
  16 public class WebSlcEventListenerRegister implements SlcEventListenerRegister,
  17                 Serializable {
  18         private final static Log log = LogFactory
  19                         .getLog(WebSlcEventListenerRegister.class);
  20         public final static String ATTR_EVENT_LISTENER = "slcEventListener";
  21
  22         static final long serialVersionUID = 1l;
  23
  24         transient private SlcEventListener eventListener = null;
  25
  26         private String clientId = null;
  27
  28         /** Synchronized */
  29         private List<SlcEventListenerDescriptor> descriptors = new Vector<SlcEventListenerDescriptor>();
  30
  31         public synchronized void addEventListenerDescriptor(
  32                         SlcEventListenerDescriptor eventListenerDescriptor) {
  33                 if (descriptors.contains(eventListenerDescriptor))
  34                         descriptors.remove(eventListenerDescriptor);
  35                 descriptors.add(eventListenerDescriptor);
  36         }
  37
  38         public synchronized void removeEventListenerDescriptor(
  39                         SlcEventListenerDescriptor eventListenerDescriptor) {
  40                 descriptors.remove(eventListenerDescriptor);
  41         }
  42
  43         // public synchronized List<SlcEventListenerDescriptor> getDescriptorsCopy()
  44         // {
  45         // return new ArrayList<SlcEventListenerDescriptor>(descriptors);
  46         // }
  47
  48         public SlcEvent listen(SlcEventListener eventListener, Long timeout) {
  49                 checkClientId();
  50                 this.eventListener = eventListener;
  51                 return this.eventListener.listen(clientId, descriptors, timeout);
  52         }
  53
  54         public void init() {
  55                 clientId = getSessionId();
  56                 checkClientId();
  57
  58                 if (log.isDebugEnabled())
  59                         log.debug("Initialized web event listener " + clientId);
  60         }
  61
  62         public void close() {
  63                 checkClientId();
  64                 if (eventListener != null)
  65                         eventListener.close(clientId);
  66
  67                 if (log.isDebugEnabled())
  68                         log.debug("Closed web event listener " + clientId);
  69         }
  70
  71         protected void checkClientId() {
  72                 String sessionId = getSessionId();
  73                 if (clientId == null || !clientId.equals(sessionId))
  74                         throw new SlcException("Client id " + clientId
  75                                         + " not consistent with web session id " + sessionId);
  76         }
  77
  78         protected String getSessionId() {
  79                 return RequestContextHolder.currentRequestAttributes().getSessionId();
  80         }
  81
  82         public String getClientId() {
  83                 return clientId;
  84         }
  85
  86 }