Java tutorial
/** * 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.hawtdb; import java.io.File; import java.io.IOException; import java.util.Collections; import java.util.Iterator; import java.util.LinkedHashSet; import java.util.Map; import java.util.Set; import java.util.concurrent.TimeUnit; import org.apache.camel.CamelContext; import org.apache.camel.Exchange; import org.apache.camel.impl.ServiceSupport; import org.apache.camel.spi.RecoverableAggregationRepository; import org.apache.camel.util.ObjectHelper; import org.apache.camel.util.ServiceHelper; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.fusesource.hawtbuf.Buffer; import org.fusesource.hawtdb.api.SortedIndex; import org.fusesource.hawtdb.api.Transaction; /** * An instance of AggregationRepository which is backed by a HawtDB. */ public class HawtDBAggregationRepository extends ServiceSupport implements RecoverableAggregationRepository { private static final transient Log LOG = LogFactory.getLog(HawtDBAggregationRepository.class); private HawtDBFile hawtDBFile; private String persistentFileName; private String repositoryName; private int bufferSize = 8 * 1024 * 1024; private boolean sync = true; private short pageSize = 512; private boolean returnOldExchange; private HawtDBCamelCodec codec = new HawtDBCamelCodec(); private long recoveryInterval = 5000; private boolean useRecovery = true; private int maximumRedeliveries; private String deadLetterUri; /** * Creates an aggregation repository */ public HawtDBAggregationRepository() { } /** * Creates an aggregation repository * * @param repositoryName the repository name */ public HawtDBAggregationRepository(String repositoryName) { ObjectHelper.notEmpty(repositoryName, "repositoryName"); this.repositoryName = repositoryName; } /** * Creates an aggregation repository using a new {@link org.apache.camel.component.hawtdb.HawtDBFile} * that persists using the provided file. * * @param repositoryName the repository name * @param persistentFileName the persistent store filename */ public HawtDBAggregationRepository(String repositoryName, String persistentFileName) { ObjectHelper.notEmpty(repositoryName, "repositoryName"); ObjectHelper.notEmpty(persistentFileName, "persistentFileName"); this.repositoryName = repositoryName; this.persistentFileName = persistentFileName; } /** * Creates an aggregation repository using the provided {@link org.apache.camel.component.hawtdb.HawtDBFile}. * * @param repositoryName the repository name * @param hawtDBFile the hawtdb file to use as persistent store */ public HawtDBAggregationRepository(String repositoryName, HawtDBFile hawtDBFile) { ObjectHelper.notEmpty(repositoryName, "repositoryName"); ObjectHelper.notNull(hawtDBFile, "hawtDBFile"); this.hawtDBFile = hawtDBFile; this.repositoryName = repositoryName; } public Exchange add(final CamelContext camelContext, final String key, final Exchange exchange) { if (LOG.isDebugEnabled()) { LOG.debug("Adding key [" + key + "] -> " + exchange); } try { // If we could guarantee that the key and exchange are immutable, // then we could have stuck them directly into the index, // HawtDB could then eliminate the need to marshal and un-marshal // in some cases. But since we can't.. we are going to force // early marshaling. final Buffer keyBuffer = codec.marshallKey(key); final Buffer exchangeBuffer = codec.marshallExchange(camelContext, exchange); Buffer rc = hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { SortedIndex<Buffer, Buffer> index = hawtDBFile.getRepositoryIndex(tx, repositoryName, true); return index.put(keyBuffer, exchangeBuffer); } @Override public String toString() { return "Adding key [" + key + "]"; } }); if (rc == null) { return null; } // only return old exchange if enabled if (isReturnOldExchange()) { return codec.unmarshallExchange(camelContext, rc); } } catch (IOException e) { throw new RuntimeException("Error adding to repository " + repositoryName + " with key " + key, e); } return null; } public Exchange get(final CamelContext camelContext, final String key) { Exchange answer = null; try { final Buffer keyBuffer = codec.marshallKey(key); Buffer rc = hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { SortedIndex<Buffer, Buffer> index = hawtDBFile.getRepositoryIndex(tx, repositoryName, false); if (index == null) { return null; } return index.get(keyBuffer); } @Override public String toString() { return "Getting key [" + key + "]"; } }); if (rc != null) { answer = codec.unmarshallExchange(camelContext, rc); } } catch (IOException e) { throw new RuntimeException("Error getting key " + key + " from repository " + repositoryName, e); } if (LOG.isDebugEnabled()) { LOG.debug("Getting key [" + key + "] -> " + answer); } return answer; } public void remove(final CamelContext camelContext, final String key, final Exchange exchange) { if (LOG.isDebugEnabled()) { LOG.debug("Removing key [" + key + "]"); } try { final Buffer keyBuffer = codec.marshallKey(key); final Buffer confirmKeyBuffer = codec.marshallKey(exchange.getExchangeId()); final Buffer exchangeBuffer = codec.marshallExchange(camelContext, exchange); hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { SortedIndex<Buffer, Buffer> index = hawtDBFile.getRepositoryIndex(tx, repositoryName, true); // remove from the in progress index index.remove(keyBuffer); // and add it to the confirmed index SortedIndex<Buffer, Buffer> indexCompleted = hawtDBFile.getRepositoryIndex(tx, getRepositoryNameCompleted(), true); indexCompleted.put(confirmKeyBuffer, exchangeBuffer); return null; } @Override public String toString() { return "Removing key [" + key + "]"; } }); } catch (IOException e) { throw new RuntimeException("Error removing key " + key + " from repository " + repositoryName, e); } } public void confirm(final CamelContext camelContext, final String exchangeId) { if (LOG.isDebugEnabled()) { LOG.debug("Confirming exchangeId [" + exchangeId + "]"); } try { final Buffer confirmKeyBuffer = codec.marshallKey(exchangeId); hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { SortedIndex<Buffer, Buffer> indexCompleted = hawtDBFile.getRepositoryIndex(tx, getRepositoryNameCompleted(), true); return indexCompleted.remove(confirmKeyBuffer); } @Override public String toString() { return "Confirming exchangeId [" + exchangeId + "]"; } }); } catch (IOException e) { throw new RuntimeException( "Error confirming exchangeId " + exchangeId + " from repository " + repositoryName, e); } } public Set<String> getKeys() { final Set<String> keys = new LinkedHashSet<String>(); hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { // interval task could potentially be running while we are shutting down so check for that if (!isRunAllowed()) { return null; } SortedIndex<Buffer, Buffer> index = hawtDBFile.getRepositoryIndex(tx, repositoryName, false); if (index == null) { return null; } Iterator<Map.Entry<Buffer, Buffer>> it = index.iterator(); // scan could potentially be running while we are shutting down so check for that while (it.hasNext() && isRunAllowed()) { Map.Entry<Buffer, Buffer> entry = it.next(); Buffer keyBuffer = entry.getKey(); String key; try { key = codec.unmarshallKey(keyBuffer); } catch (IOException e) { throw new RuntimeException("Error unmarshalling key: " + keyBuffer, e); } if (key != null) { if (LOG.isTraceEnabled()) { LOG.trace("getKey [" + key + "]"); } keys.add(key); } } return null; } @Override public String toString() { return "getKeys"; } }); return Collections.unmodifiableSet(keys); } public Set<String> scan(CamelContext camelContext) { final Set<String> answer = new LinkedHashSet<String>(); hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { // scan could potentially be running while we are shutting down so check for that if (!isRunAllowed()) { return null; } SortedIndex<Buffer, Buffer> indexCompleted = hawtDBFile.getRepositoryIndex(tx, getRepositoryNameCompleted(), false); if (indexCompleted == null) { return null; } Iterator<Map.Entry<Buffer, Buffer>> it = indexCompleted.iterator(); // scan could potentially be running while we are shutting down so check for that while (it.hasNext() && isRunAllowed()) { Map.Entry<Buffer, Buffer> entry = it.next(); Buffer keyBuffer = entry.getKey(); String exchangeId; try { exchangeId = codec.unmarshallKey(keyBuffer); } catch (IOException e) { throw new RuntimeException("Error unmarshalling confirm key: " + keyBuffer, e); } if (exchangeId != null) { if (LOG.isTraceEnabled()) { LOG.trace("Scan exchangeId [" + exchangeId + "]"); } answer.add(exchangeId); } } return null; } @Override public String toString() { return "Scan"; } }); if (answer.size() == 0) { LOG.trace("Scanned and found no exchange to recover."); } else { if (LOG.isDebugEnabled()) { LOG.debug("Scanned and found " + answer.size() + " exchange(s) to recover (note some of them may already be in progress)."); } } return answer; } public Exchange recover(CamelContext camelContext, final String exchangeId) { Exchange answer = null; try { final Buffer confirmKeyBuffer = codec.marshallKey(exchangeId); Buffer rc = hawtDBFile.execute(new Work<Buffer>() { public Buffer execute(Transaction tx) { SortedIndex<Buffer, Buffer> indexCompleted = hawtDBFile.getRepositoryIndex(tx, getRepositoryNameCompleted(), false); if (indexCompleted == null) { return null; } return indexCompleted.get(confirmKeyBuffer); } @Override public String toString() { return "Recovering exchangeId [" + exchangeId + "]"; } }); if (rc != null) { answer = codec.unmarshallExchange(camelContext, rc); } } catch (IOException e) { throw new RuntimeException( "Error recovering exchangeId " + exchangeId + " from repository " + repositoryName, e); } if (LOG.isDebugEnabled()) { LOG.debug("Recovering exchangeId [" + exchangeId + "] -> " + answer); } return answer; } private int size(final String repositoryName) { int answer = hawtDBFile.execute(new Work<Integer>() { public Integer execute(Transaction tx) { SortedIndex<Buffer, Buffer> index = hawtDBFile.getRepositoryIndex(tx, repositoryName, false); return index != null ? index.size() : 0; } @Override public String toString() { return "Size[" + repositoryName + "]"; } }); if (LOG.isDebugEnabled()) { LOG.debug("Size of repository [" + repositoryName + "] -> " + answer); } return answer; } public HawtDBFile getHawtDBFile() { return hawtDBFile; } public void setHawtDBFile(HawtDBFile hawtDBFile) { this.hawtDBFile = hawtDBFile; } public String getRepositoryName() { return repositoryName; } private String getRepositoryNameCompleted() { return repositoryName + "-completed"; } public void setRepositoryName(String repositoryName) { this.repositoryName = repositoryName; } public String getPersistentFileName() { return persistentFileName; } public void setPersistentFileName(String persistentFileName) { this.persistentFileName = persistentFileName; } public boolean isSync() { return sync; } public void setSync(boolean sync) { this.sync = sync; } public Integer getBufferSize() { return bufferSize; } public void setBufferSize(Integer bufferSize) { this.bufferSize = bufferSize; } public boolean isReturnOldExchange() { return returnOldExchange; } public void setReturnOldExchange(boolean returnOldExchange) { this.returnOldExchange = returnOldExchange; } public void setRecoveryInterval(long interval, TimeUnit timeUnit) { this.recoveryInterval = timeUnit.toMillis(interval); } public void setRecoveryInterval(long interval) { this.recoveryInterval = interval; } public long getRecoveryIntervalInMillis() { return recoveryInterval; } public boolean isUseRecovery() { return useRecovery; } public void setUseRecovery(boolean useRecovery) { this.useRecovery = useRecovery; } public int getMaximumRedeliveries() { return maximumRedeliveries; } public void setMaximumRedeliveries(int maximumRedeliveries) { this.maximumRedeliveries = maximumRedeliveries; } public String getDeadLetterUri() { return deadLetterUri; } public void setDeadLetterUri(String deadLetterUri) { this.deadLetterUri = deadLetterUri; } public short getPageSize() { return pageSize; } public void setPageSize(short pageSize) { this.pageSize = pageSize; } @Override protected void doStart() throws Exception { // either we have a HawtDB configured or we use a provided fileName if (hawtDBFile == null && persistentFileName != null) { hawtDBFile = new HawtDBFile(); hawtDBFile.setFile(new File(persistentFileName)); hawtDBFile.setSync(isSync()); if (getBufferSize() != null) { hawtDBFile.setMappingSegementSize(getBufferSize()); } if (getPageSize() > 0) { hawtDBFile.setPageSize(getPageSize()); } } ObjectHelper.notNull(hawtDBFile, "Either set a persistentFileName or a hawtDBFile"); ObjectHelper.notNull(repositoryName, "repositoryName"); ServiceHelper.startService(hawtDBFile); // log number of existing exchanges int current = size(getRepositoryName()); int completed = size(getRepositoryNameCompleted()); if (current > 0) { LOG.info("On startup there are " + current + " aggregate exchanges (not completed) in repository: " + getRepositoryName()); } else { LOG.info("On startup there are no existing aggregate exchanges (not completed) in repository: " + getRepositoryName()); } if (completed > 0) { LOG.warn("On startup there are " + completed + " completed exchanges to be recovered in repository: " + getRepositoryNameCompleted()); } else { LOG.info("On startup there are no completed exchanges to be recovered in repository: " + getRepositoryNameCompleted()); } } @Override protected void doStop() throws Exception { ServiceHelper.stopService(hawtDBFile); } }