| /** |
| * 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.camel.component.zookeeper; |
| |
| import java.util.concurrent.ExecutorService; |
| import java.util.concurrent.LinkedBlockingQueue; |
| |
| import org.apache.camel.Exchange; |
| import org.apache.camel.Processor; |
| import org.apache.camel.component.zookeeper.operations.AnyOfOperations; |
| import org.apache.camel.component.zookeeper.operations.ChildrenChangedOperation; |
| import org.apache.camel.component.zookeeper.operations.DataChangedOperation; |
| import org.apache.camel.component.zookeeper.operations.ExistenceChangedOperation; |
| import org.apache.camel.component.zookeeper.operations.ExistsOperation; |
| import org.apache.camel.component.zookeeper.operations.GetChildrenOperation; |
| import org.apache.camel.component.zookeeper.operations.GetDataOperation; |
| import org.apache.camel.component.zookeeper.operations.OperationResult; |
| import org.apache.camel.component.zookeeper.operations.ZooKeeperOperation; |
| import org.apache.camel.impl.DefaultConsumer; |
| import org.apache.zookeeper.WatchedEvent; |
| import org.apache.zookeeper.ZooKeeper; |
| |
| |
| /** |
| * <code>ZooKeeperConsumer</code> uses various {@link ZooKeeperOperation} to |
| * interact and consume data from a ZooKeeper cluster. |
| */ |
| @SuppressWarnings("rawtypes") |
| public class ZooKeeperConsumer extends DefaultConsumer { |
| |
| private final ZooKeeperConnectionManager zkm; |
| private ZooKeeper connection; |
| private ZooKeeperConfiguration configuration; |
| private LinkedBlockingQueue<ZooKeeperOperation> operations = new LinkedBlockingQueue<ZooKeeperOperation>(); |
| private ExecutorService executor; |
| private volatile boolean shuttingDown; |
| |
| public ZooKeeperConsumer(ZooKeeperEndpoint endpoint, Processor processor) { |
| super(endpoint, processor); |
| this.zkm = endpoint.getConnectionManager(); |
| this.configuration = endpoint.getConfiguration(); |
| } |
| |
| @Override |
| protected void doStart() throws Exception { |
| super.doStart(); |
| connection = zkm.getConnection(); |
| if (log.isDebugEnabled()) { |
| log.debug(String.format("Connected to Zookeeper cluster %s", configuration.getConnectString())); |
| } |
| |
| initializeConsumer(); |
| executor = getEndpoint().getCamelContext().getExecutorServiceManager().newFixedThreadPool(configuration.getPath(), "Camel-Zookeeper Ops executor", 1); |
| |
| OperationsExecutor opsService = new OperationsExecutor(); |
| executor.submit(opsService); |
| } |
| |
| @Override |
| protected void doStop() throws Exception { |
| super.doStop(); |
| shuttingDown = true; |
| if (log.isTraceEnabled()) { |
| log.trace(String.format("Shutting down zookeeper consumer of '%s'", configuration.getPath())); |
| } |
| getEndpoint().getCamelContext().getExecutorServiceManager().shutdown(executor); |
| zkm.shutdown(); |
| } |
| |
| private void initializeConsumer() { |
| String node = configuration.getPath(); |
| if (configuration.isListChildren()) { |
| initializeChildListingConsumer(node); |
| } else { |
| initializeDataConsumer(node); |
| } |
| } |
| |
| private void initializeDataConsumer(String node) { |
| if (!shuttingDown) { |
| if (log.isDebugEnabled()) { |
| log.debug(String.format("Initializing consumption of data on node '%s'", node)); |
| } |
| addBasicDataConsumeSequence(node); |
| } |
| } |
| |
| private void initializeChildListingConsumer(String node) { |
| if (!shuttingDown) { |
| if (log.isDebugEnabled()) { |
| log.debug(String.format("Initializing child listing of node '%s'", node)); |
| } |
| addBasicChildListingSequence(node); |
| } |
| } |
| |
| private Exchange createExchange(String path, OperationResult result, WatchedEvent watchedEvent) { |
| Exchange e = getEndpoint().createExchange(); |
| ZooKeeperMessage in = new ZooKeeperMessage(path, result.getStatistics(), watchedEvent); |
| e.setIn(in); |
| if (result.isOk()) { |
| in.setBody(result.getResult()); |
| } else { |
| e.setException(result.getException()); |
| } |
| return e; |
| } |
| |
| private class OperationsExecutor implements Runnable { |
| |
| private ZooKeeperOperation current; |
| |
| private WatchedEvent watchedEvent; |
| |
| public void run() { |
| while (isRunAllowed()) { |
| |
| try { |
| current = operations.take(); |
| if (log.isTraceEnabled()) { |
| log.trace(String.format("Processing '%s' operation", current.getClass().getSimpleName())); |
| } |
| } catch (InterruptedException e) { |
| continue; |
| } |
| String node = current.getNode(); |
| try { |
| OperationResult result = current.get(); |
| if (ZooKeeperUtils.hasWatchedEvent(current)) { |
| watchedEvent = ZooKeeperUtils.getWatchedEvent(current); |
| } |
| if (result != null && current.shouldProduceExchange()) { |
| getProcessor().process(createExchange(node, result, watchedEvent)); |
| watchedEvent = null; |
| } |
| } catch (Exception e) { |
| handleException(e); |
| backoffAndThenRestart(); |
| } finally { |
| if (configuration.isRepeat()) { |
| try { |
| operations.offer(current.createCopy()); |
| } catch (Exception e) { |
| backoffAndThenRestart(); |
| } |
| } |
| } |
| } |
| } |
| |
| private void backoffAndThenRestart() { |
| try { |
| if (isRunAllowed()) { |
| Thread.sleep(configuration.getBackoff()); |
| initializeConsumer(); |
| } |
| } catch (Exception e) { |
| } |
| } |
| } |
| |
| private void addBasicDataConsumeSequence(String node) { |
| operations.clear(); |
| operations.add(new AnyOfOperations(node, new ExistsOperation(connection, node), new ExistenceChangedOperation(connection, node))); |
| operations.add(new GetDataOperation(connection, node)); |
| operations.add(new DataChangedOperation(connection, node, false, configuration.isSendEmptyMessageOnDelete())); |
| } |
| |
| private void addBasicChildListingSequence(String node) { |
| operations.clear(); |
| operations.add(new AnyOfOperations(node, new ExistsOperation(connection, node), new ExistenceChangedOperation(connection, node))); |
| operations.add(new GetChildrenOperation(connection, node)); |
| operations.add(new ChildrenChangedOperation(connection, node, false)); |
| } |
| } |