diff options
Diffstat (limited to 'trunk/qpid/java/management/client/src/main/java/org/apache/qpid/management/domain/services/BrokerMessageListener.java')
| -rw-r--r-- | trunk/qpid/java/management/client/src/main/java/org/apache/qpid/management/domain/services/BrokerMessageListener.java | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/trunk/qpid/java/management/client/src/main/java/org/apache/qpid/management/domain/services/BrokerMessageListener.java b/trunk/qpid/java/management/client/src/main/java/org/apache/qpid/management/domain/services/BrokerMessageListener.java new file mode 100644 index 0000000000..fc9819fce4 --- /dev/null +++ b/trunk/qpid/java/management/client/src/main/java/org/apache/qpid/management/domain/services/BrokerMessageListener.java @@ -0,0 +1,183 @@ +/* + * + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + * + */ +package org.apache.qpid.management.domain.services; + +import java.io.IOException; +import java.nio.ByteBuffer; +import java.util.Arrays; +import java.util.HashMap; +import java.util.Map; +import java.util.Map.Entry; + +import org.apache.qpid.api.Message; +import org.apache.qpid.management.Messages; +import org.apache.qpid.management.Protocol; +import org.apache.qpid.management.domain.handler.base.IMessageHandler; +import org.apache.qpid.management.domain.model.DomainModel; +import org.apache.qpid.nclient.util.MessageListener; +import org.apache.qpid.transport.codec.BBDecoder; +import org.apache.qpid.transport.util.Logger; + +/** + * Message listener used for processing incoming messages. + * So it is installed as a consumer on a specific channel and when a new message arrives: + * + * 1) Performs a sanity check on the message (magic number, sequence number) + * 2) Extracts the opcode and looks for one message handler associated with that opcode. + * 3) If a message handler is found the delegates the message processing; otherwise a log message is written to indicate + * that the message will be skipped. + * + * @author Andrea Gazzarini + */ +class BrokerMessageListener implements MessageListener +{ + private final static Logger LOGGER = Logger.get(BrokerMessageListener.class); + + private static class Log + { + // Debugs the content of the incoming message. + static void debugIncomingMessage(ByteBuffer message) + { + if (LOGGER.isDebugEnabled()) + { + LOGGER.debug(Messages.QMAN_200001_INCOMING_MESSAGE_HAS_BEEN_RECEIVED, Arrays.toString(message.array())); + } + } + + // Debugs all the configured handlers. + static void debugConfiguredHandlers (Map<Character, IMessageHandler> _handlers) + { + if (LOGGER.isDebugEnabled()) + { + for (Entry<Character, IMessageHandler> entry : _handlers.entrySet()) + { + LOGGER.debug(Messages.QMAN_200002_OPCODE_HANDLER_ASSOCIATION,entry.getKey(),entry.getValue()); + } + } + } + } + + Map<Character, IMessageHandler> _handlers = new HashMap<Character, IMessageHandler>(); + private DomainModel _domainModel; + + /** + * Builds a new message listener with the given broker domain model. + * + * @param model the managed broker domain model. + */ + BrokerMessageListener(DomainModel model) + { + this._domainModel = model; + } + + /** + * When a new message arrives this method is called. + * 1) Performs a sanity check on the message (magic number, sequence number) + * 2) Extracts the opcode and looks for one message handler associated with that opcode. + * 3) If a message handler is found the delegates the message processing; otherwise a log message is written to indicate + * that the message will be skipped. + * + * @param message the incoming message. + */ + public void onMessage (Message compoundMessage) + { + try + { + MessageTokenizer tokenizer = new MessageTokenizer(compoundMessage); + while (tokenizer.hasMoreElements()) + { + dispatch(tokenizer.nextElement()); + } + } catch(IOException exception) + { + LOGGER.error(exception,Messages.QMAN_100002_MESSAGE_READ_FAILURE); + } catch(Exception exception) + { + LOGGER.error(exception,Messages.QMAN_100003_MESSAGE_PROCESS_FAILURE); + } + } + + /** + * Configures a new handler with this listener. + * After that, each time a message arrives with the specified opcode, this handler will be responsible for + * processing. + * Note that calling this method will switch this listener to a WORKING state. + * + * @param opcode the operation code. + * @param handler the message handler. + */ + void setHandlers(Map<Character, IMessageHandler> handlers) + { + for (Entry<Character, IMessageHandler> entry : handlers.entrySet()) + { + char opcode = entry.getKey(); + IMessageHandler handler = entry.getValue(); + try + { + handler.setDomainModel(_domainModel); + _handlers.put(opcode, handler); + } catch (Exception exception) { + LOGGER.error(exception, + Messages.QMAN_100004_HANDLER_INITIALIZATION_FAILURE, + opcode); + } + } + } + + + + /** + * Dispatches the given message to the appropriate handler. + * + * @param message + * the incoming message. + * @throws IOException + * when the message content cannot be read. + */ + private void dispatch(Message message) throws IOException + { + ByteBuffer buffer = message.readData(); + + String magicNumber = new String(new byte[] {buffer.get(),buffer.get(),buffer.get()}); + if (!Protocol.MAGIC_NUMBER.equals(magicNumber)) + { + LOGGER.error(Messages.QMAN_100001_BAD_MAGIC_NUMBER_FAILURE,magicNumber); + return; + } + + char opcode = (char)buffer.get(); + + IMessageHandler handler = _handlers.get(opcode); + if (handler != null) + { + BBDecoder decoder = new BBDecoder(); + decoder.init(buffer); + + LOGGER.debug(Messages.QMAN_200003_MESSAGE_FORWARDING,opcode,handler); + + handler.process(decoder,decoder.readSequenceNo()); + } else + { + LOGGER.warn(Messages.QMAN_300001_MESSAGE_DISCARDED,opcode); + Log.debugConfiguredHandlers(_handlers); + } + } +} |