agentmobilityservice.java

java实现的P2P多agent中间件

				}
				else if(cmdName.equals(AgentMobilitySlice.H_TRANSFERIDENTITY)) {
					AID agentID = (AID)params[0];
					Location src = (Location)params[1];
					Location dest = (Location)params[2];
					
					cmd.setReturnValue(new Boolean(transferIdentity(agentID, src, dest)));
				}
				else if(cmdName.equals(AgentMobilitySlice.H_HANDLETRANSFERRESULT)) {
					AID agentID = (AID)params[0];
					boolean transferResult = ((Boolean)params[1]).booleanValue();
					List messages = (List)params[2];
					
					handleTransferResult(agentID, transferResult, messages);
				}
				else if(cmdName.equals(AgentMobilitySlice.H_CLONEDAGENT)) {
					GenericCommand gCmd = new GenericCommand(AgentMobilityHelper.INFORM_CLONED, AgentMobilitySlice.NAME, null);
					AID agentID = (AID)params[0];
					ContainerID cid = (ContainerID)params[1];
					Credentials creds = (Credentials)params[2];
					gCmd.addParam(agentID);
					gCmd.addParam(cid);
					gCmd.addParam(creds);
					
					result = gCmd;
				}
				//#J2ME_EXCLUDE_BEGIN
				else if(cmdName.equals(AgentMobilitySlice.H_CLONECODELOCATORENTRY)) {
					AID oldAgentID = (AID)params[0];
					AID newAgentID = (AID)params[1];
					
					handleCloneCodeLocatorEntry(oldAgentID, newAgentID);
				}
				else if(cmdName.equals(AgentMobilitySlice.H_REMOVECODELOCATORENTRY)) {
					AID agentID = (AID)params[0];

					handleRemoveCodeLocatorEntry(agentID);
				}
				//#J2ME_EXCLUDE_END
			}
			catch(Throwable t) {
				cmd.setReturnValue(t);
				if(result != null) {
					result.setReturnValue(t);
				}
			}
			
			return result;
		}
		
		
		private void createAgent(AID agentID, byte[] serializedInstance, String classSiteName, boolean isCloned, boolean startIt) throws IMTPException, ServiceException, NotFoundException, NameClashException, JADESecurityException {
			try {
				//log("Incoming agent " + agentID, 1);
				if(myLogger.isLoggable(Logger.CONFIG))
					myLogger.log(Logger.CONFIG,"Incoming agent " + agentID.getName());
				
				
				// Reconstruct the serialized agent
				//#DOTNET_EXCLUDE_BEGIN
				ObjectInputStream in = new Deserializer(new ByteArrayInputStream(serializedInstance), agentID.getName(), classSiteName, myContainer.getServiceFinder());
				Agent instance = (Agent)in.readObject();
				//#DOTNET_EXCLUDE_END
				/*#DOTNET_INCLUDE_BEGIN
				 ubyte[] ubyteSerializedInstance = new ubyte[serializedInstance.length];
				 System.Buffer.BlockCopy(serializedInstance, 0, ubyteSerializedInstance, 0, serializedInstance.length);
				 ByteArrayInputStream in = new ByteArrayInputStream(serializedInstance);
				 ObjectInputStream decoder = new ObjectInputStream(in);
				 Object obj = decoder.readObject();
				 
				 Agent instance = (Agent) obj;
				 #DOTNET_INCLUDE_END*/
				
				//log("Agent " + agentID + " reconstructed", 2);
				if(myLogger.isLoggable(Logger.FINE))
					myLogger.log(Logger.FINE,"Agent " + agentID + " reconstructed");
				
				
				
				/* --- This code should go into the Security Service ---
				 
				 // agent is about to be created on the destination Container,
				  // let's check for permissions before
				   
				   // does the agent come from a MOVE or a CLONE ?
				    switch (instance.getState()) {
				    case Agent.AP_TRANSIT:  // MOVED
				    // checking CONTAINER_MOVE_TO...
				     myContainer.getAuthority().checkAction(
				     Authority.CONTAINER_MOVE_TO,
				     myContainer.getContainerPrincipal(),
				     instance.getCertificateFolder()  );
				     break;
				     case Agent.AP_COPY:  // CLONED
				     // checking CONTAINER_CLONE_TO...
				      myContainer.getAuthority().checkAction(
				      Authority.CONTAINER_CLONE_TO,
				      myContainer.getContainerPrincipal(),
				      instance.getCertificateFolder()  );
				      break;
				      } // end switch
				      
				      log("Permissions for agent " + agentID + " OK", 2);
				      
				      // --- End of code that should go into the Security Service ---
				       */
				
				Credentials agentCerts = null;
				//#MIDP_EXCLUDE_BEGIN
				//CertificateFolder agentCerts = instance.getCertificateFolder();
				//#MIDP_EXCLUDE_END
				
				/*# MIDP_INCLUDE_BEGIN
				 CertificateFolder agentCerts = new CertificateFolder();
				 # MIDP_INCLUDE_END*/
				
				if(isCloned) {
					// Notify the main slice that a new agent is born
					AgentMobilitySlice mainSlice = (AgentMobilitySlice)getSlice(MAIN_SLICE);
					
					try {
						mainSlice.clonedAgent(agentID, myContainer.getID(), agentCerts);
					}
					catch(IMTPException imtpe) {
						// Try to get a newer slice and repeat...
						mainSlice = (AgentMobilitySlice)getFreshSlice(MAIN_SLICE);
						mainSlice.clonedAgent(agentID, myContainer.getID(), agentCerts);
					}
				}
				
				// Store the container where the classes for this agent can be
				// retrieved
				sites.put(instance, classSiteName);
				
				// Connect the new instance to the local container
				Agent old = myContainer.addLocalAgent(agentID, instance);
				
				if(startIt) {
					// Actually start the agent thread
					myContainer.powerUpLocalAgent(agentID);
				}
				
				//log("Agent " + agentID + " inserted into LADT", 1);
				if(myLogger.isLoggable(Logger.FINE))
					myLogger.log(Logger.FINE,"Agent " + agentID.getName() + " inserted into LADT");
				
			}
			catch(IOException ioe) {
				throw new IMTPException("An I/O error occurred during de-serialization", ioe);
			}
			catch(ClassNotFoundException cnfe) {
				throw new IMTPException("A class was not found during de-serialization", cnfe);
			}
			catch(Throwable t) {
				t.printStackTrace();
				throw new IMTPException("Unexpected error.", t);
			}
		}
		
		private byte[] fetchClassFile(String className, String agentName) throws IMTPException, ClassNotFoundException {
			if (myLogger.isLoggable(Logger.FINE))
				myLogger.log(Logger.FINE, "Fetching class " + className);
			
			String fileName = className.replace('.', '/') + ".class";
			int length = -1;
			InputStream classStream = getClass().getClassLoader().getResourceAsStream(fileName);
			if (classStream == null) {
				// This is likely redundant, but...
				classStream = ClassLoader.getSystemResourceAsStream(fileName);
			}
			if (classStream == null) {
				// In PJAVA for some misterious reason getSystemResourceAsStream()
				// does not work --> Try to do it by hand
				if (myLogger.isLoggable(Logger.FINER))
					myLogger.log(Logger.FINER, "Class not found as a system resource. Try manually");

				String currentCp = System.getProperty("java.class.path");
				StringTokenizer st = new StringTokenizer(currentCp, File.pathSeparator);
				while (st.hasMoreTokens()) {
					try {
						String path = st.nextToken();
						if (myLogger.isLoggable(Logger.FINER)) {
							myLogger.log(Logger.FINER, "Searching in path " + path);
						}
						if (path.endsWith(".jar")) {
							if (myLogger.isLoggable(Logger.FINER)) {
								myLogger.log(Logger.FINER, "It's a jar file");
							}

							ClassInfo info = getClassStreamFromJar(fileName, path);
							if (info != null) {
								classStream = info.getClassStream();
								length = info.getLength();
								break;
							}
						} 
						else {
							if (myLogger.isLoggable(Logger.FINER)) {
								myLogger.log(Logger.FINER, "Trying file " + path + "/" + fileName);
							}
							
							File f = new File(path + "/" + fileName);
							if (f.exists()) {
								if (myLogger.isLoggable(Logger.FINER)) {
									myLogger.log(Logger.FINER, "File exists");
								}
								classStream = new FileInputStream(f);
								break;
							}
						}
					} 
					catch (Exception e) {
						if (myLogger.isLoggable(Logger.WARNING)) {
							myLogger.log(Logger.WARNING, e.toString());
						}
					}
				}
			}
			//#J2ME_EXCLUDE_BEGIN
			if (classStream == null && agentName != null) {
				// Maybe the agent was loaded from a separate Jar file
				try {
					AgentManagementService amSrv = (AgentManagementService) myFinder.findService(AgentManagementService.NAME);
					ClassLoader cLoader = amSrv.getCodeLocator().getAgentClassLoader(new AID(agentName, AID.ISGUID));
					InputStream is = cLoader.getResourceAsStream(fileName);

					// We assign length -1 because in a generic InputStream
					// the length is not known a priori.
					ClassInfo info = new ClassInfo(is, -1);
					classStream = info.getClassStream();
					length = info.getLength();
				}
				catch (NullPointerException npe) {
					// No jarfile or class not found in jarfile. Ignore
				}
				catch (Exception e) {
					// Should never happen since findService() never throws exceptions
					e.printStackTrace();
				}
			}
			//#J2ME_EXCLUDE_END
			if (classStream == null) {
				if (myLogger.isLoggable(Logger.WARNING)) {
					myLogger.log(Logger.WARNING, "Class " + className + " not found");
				}
				throw new ClassNotFoundException(className);
			}
			
			try {
				
				// Length is used no more because we read until the end of the stream.
				//if (length == -1) {
				//	length = (int) classStream.available();
				//}
				
				ByteArrayOutputStream baos = new ByteArrayOutputStream();
				byte[] bytes = new byte[SIZE_JAR_BUFFER];
				int read = 0;
				if (myLogger.isLoggable(Logger.FINER)) {
					myLogger.log(Logger.FINER, "Class " + className + " fetched. Length is " + length);
				}
				
				DataInputStream dis = new DataInputStream(classStream);
				while ((read = dis.read(bytes)) >= 0) {
					baos.write(bytes, 0, read);
				}
				
				dis.close();
				
				return (baos.toByteArray());
			} 
			catch (IOException ioe) {
				throw new ClassNotFoundException("IOException reading class bytes. " + ioe.getMessage());
			}
		}
		
		private ClassInfo getClassStreamFromJar(String classFileName, String jarName) throws IOException {
			File f = new File(jarName);
			if (f.exists()) {
				if (myLogger.isLoggable(Logger.FINER)) {
					myLogger.log(Logger.FINER, "Jar file exists");
				}
			}
			ZipFile zf = new ZipFile(f);
			ZipEntry e = zf.getEntry(classFileName);
			if (e != null) {
				if (myLogger.isLoggable(Logger.FINER)) {
					myLogger.log(Logger.FINER, "Entry " + classFileName + " found");
				}
				
				return new ClassInfo(zf.getInputStream(e), (int) e.getSize());
			}
			return null;
		}
		
		
		/**
		 * Inner class ClassInfo
		 * This utility bean class is used only to keep together some pieces of information related to a class
		 */
		private class ClassInfo {
			private InputStream classStream;
			private int length = -1;
			
			public ClassInfo(InputStream is, int l) {
				classStream = is;
				length = l;
			}
			
			public InputStream getClassStream() {
				return classStream;
			}
			
			public int getLength() {
				return length;
			}
		} // END of inner class ClassInfo
		
		
		private void handleTransferResult(AID agentID, boolean result, List messages) throws IMTPException, NotFoundException {
			//log("Activating incoming agent "+agentID, 1);
			if(myLogger.isLoggable(Logger.FINER))
				myLogger.log(Logger.FINER,"Activating incoming agent "+agentID);
			
			try {
				Agent agent = myContainer.acquireLocalAgent(agentID);
				
				if ((agent == null) || (agent.getState() != AP_TRANSIT)) {
					throw new NotFoundException("handleTransferResult() unable to find a suitable agent.");
				}
				
				if (result == TRANSFER_ABORT) {
					myContainer.removeLocalAgent(agentID);
				}
				else {
					// Insert received messages at the start of the queue
					for (int i = messages.size(); i > 0; i--) {
						agent.putBack((ACLMessage)messages.get(i - 1));
					}
					
					myContainer.powerUpLocalAgent(agentID);
					//log("Incoming agent " + agentID + " activated", 1);
					if(myLogger.isLoggable(Logger.CONFIG))
						myLogger.log(Logger.CONFIG,"Incoming agent " + agentID.getName() + " activated");
					
				}
			}
			finally {
				myContainer.releaseLocalAgent(agentID);
			}
		}
		
		private boolean prepare() {
			// Just return 'true', because this method is simply used as a 'ping', for now...
			return true;
		}
		
		private boolean transferIdentity(AID agentID, Location src, Location dest) throws IMTPException, NotFoundException {
			//log("Transferring identity of agent "+agentID+" from "+src.getName()+" to "+dest.getName(), 2);
			if(myLogger.isLoggable(Logger.FINE))
				myLogger.log(Logger.FINE,"Transferring identity of agent "+agentID+" from "+src.getName()+" to "+dest.getName());
			
			
			MainContainer impl = myContainer.getMain();
			if(impl != null) {
				AgentDescriptor ad = impl.acquireAgentDescriptor(agentID);
				if (ad != null) {
					try {
						AgentMobilitySlice srcSlice = (AgentMobilitySlice)getSlice(src.getName());
						AgentMobilitySlice destSlice = (AgentMobilitySlice)getSlice(dest.getName());
						boolean srcReady = false;
						boolean destReady = false;
						
						try {
							srcReady = srcSlice.prepare();
						}
						catch(IMTPException imtpe) {
							srcSlice = (AgentMobilitySlice)getFreshSlice(src.getName());
							srcReady = srcSlice.prepare();
						}
						//log("Source "+src.getName()+" "+srcReady, 2);
						if(myLogger.isLoggable(Logger.FINE))
							myLogger.log(Logger.FINE,"Source "+src.getName()+" "+srcReady);
						
						
						try {
							destReady = destSlice.prepare();
						}
						catch(IMTPException imtpe) {
							destSlice = (AgentMobilitySlice)getFreshSlice(dest.getName());
							destReady = destSlice.prepare();
						}
						//log("Destination "+dest.getName()+" "+destReady, 2);
						if(myLogger.isLoggable(Logger.FINE))
							myLogger.log(Logger.FINE,"Destination "+dest.getName()+" "+destReady);
						
						
						if(srcReady && destReady) {
							// FIXME: We should issue a TRANSFER_IDENTITY V-Command to allow migration tracing and prevention
							// Commit transaction
							impl.movedAgent(agentID, (ContainerID)src, (ContainerID)dest);
							return true;
						}
						else {
							// Problems on a participant slice: abort transaction
							return false;