Java tutorial
/* * Copyright 2002-2017 the original author or authors. * * Licensed 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.springframework.integration.jdbc.store; import java.sql.ResultSet; import java.sql.SQLException; import java.sql.Timestamp; import java.util.ArrayList; import java.util.Arrays; import java.util.Collection; import java.util.Date; import java.util.HashMap; import java.util.Iterator; import java.util.List; import java.util.Map; import java.util.UUID; import java.util.concurrent.atomic.AtomicReference; import javax.sql.DataSource; import org.apache.commons.logging.Log; import org.apache.commons.logging.LogFactory; import org.springframework.core.serializer.Deserializer; import org.springframework.core.serializer.Serializer; import org.springframework.core.serializer.support.DeserializingConverter; import org.springframework.core.serializer.support.SerializingConverter; import org.springframework.dao.DuplicateKeyException; import org.springframework.integration.store.AbstractMessageGroupStore; import org.springframework.integration.store.MessageGroup; import org.springframework.integration.store.MessageMetadata; import org.springframework.integration.store.MessageStore; import org.springframework.integration.store.SimpleMessageGroup; import org.springframework.integration.util.UUIDConverter; import org.springframework.jdbc.core.JdbcOperations; import org.springframework.jdbc.core.JdbcTemplate; import org.springframework.jdbc.core.RowCallbackHandler; import org.springframework.jdbc.core.RowMapper; import org.springframework.jdbc.core.SingleColumnRowMapper; import org.springframework.jdbc.support.lob.DefaultLobHandler; import org.springframework.jdbc.support.lob.LobHandler; import org.springframework.jmx.export.annotation.ManagedAttribute; import org.springframework.messaging.Message; import org.springframework.messaging.MessageChannel; import org.springframework.util.Assert; import org.springframework.util.StringUtils; /** * Implementation of {@link MessageStore} using a relational database via JDBC. SQL scripts to create the necessary * tables are packaged as <code>org/springframework/integration/jdbc/schema-*.sql</code>, where <code>*</code> is the * target database type. * <p> * If you intend backing a {@link MessageChannel} using a JDBC-based Message Store, * please consider using the channel-specific {@link JdbcChannelMessageStore} instead. * This implementation is intended for correlation components (e.g. {@code <aggregator>}), * {@code <delayer>} and similar. * * @author Dave Syer * @author Oleg Zhurakousky * @author Matt Stine * @author Gunnar Hillert * @author Will Schipp * @author Gary Russell * @author Artem Bilan * * @since 2.0 */ public class JdbcMessageStore extends AbstractMessageGroupStore implements MessageStore { private static final Log logger = LogFactory.getLog(JdbcMessageStore.class); /** * Default value for the table prefix property. */ public static final String DEFAULT_TABLE_PREFIX = "INT_"; private enum Query { GROUP_EXISTS("SELECT COUNT(GROUP_KEY) FROM %PREFIX%MESSAGE_GROUP where GROUP_KEY=? and REGION=?"), CREATE_MESSAGE_GROUP("INSERT into %PREFIX%MESSAGE_GROUP" + "(GROUP_KEY, REGION, MARKED, COMPLETE, LAST_RELEASED_SEQUENCE, CREATED_DATE, UPDATED_DATE)" + " values (?, ?, 0, 0, 0, ?, ?)"), UPDATE_MESSAGE_GROUP("UPDATE %PREFIX%MESSAGE_GROUP set UPDATED_DATE=? where GROUP_KEY=? and REGION=?"), REMOVE_MESSAGE_FROM_GROUP( "DELETE from %PREFIX%GROUP_TO_MESSAGE where GROUP_KEY=? and MESSAGE_ID=? and REGION=?"), REMOVE_GROUP_TO_MESSAGE_JOIN("DELETE from %PREFIX%GROUP_TO_MESSAGE where GROUP_KEY=? and REGION=?"), COUNT_ALL_MESSAGES_IN_GROUPS("SELECT COUNT(MESSAGE_ID) from %PREFIX%GROUP_TO_MESSAGE where REGION=?"), COUNT_ALL_MESSAGES_IN_GROUP( "SELECT COUNT(MESSAGE_ID) from %PREFIX%GROUP_TO_MESSAGE where GROUP_KEY=? and REGION=?"), LIST_MESSAGEIDS_BY_GROUP_KEY("select MESSAGE_ID, CREATED_DATE " + "from %PREFIX%MESSAGE where MESSAGE_ID in (select MESSAGE_ID from %PREFIX%GROUP_TO_MESSAGE where GROUP_KEY=? and REGION=?) " + "ORDER BY CREATED_DATE"), LIST_MESSAGES_BY_GROUP_KEY("SELECT MESSAGE_ID, MESSAGE_BYTES, CREATED_DATE " + "from %PREFIX%MESSAGE where MESSAGE_ID in (SELECT MESSAGE_ID from %PREFIX%GROUP_TO_MESSAGE where GROUP_KEY = ?) and REGION=? " + "ORDER BY CREATED_DATE"), POLL_FROM_GROUP("SELECT %PREFIX%MESSAGE.MESSAGE_ID, %PREFIX%MESSAGE.MESSAGE_BYTES from %PREFIX%MESSAGE " + "where %PREFIX%MESSAGE.MESSAGE_ID = " + "(SELECT min(m.MESSAGE_ID) from %PREFIX%MESSAGE m " + "join %PREFIX%GROUP_TO_MESSAGE on m.MESSAGE_ID = %PREFIX%GROUP_TO_MESSAGE.MESSAGE_ID " + "where CREATED_DATE = " + "(SELECT min(CREATED_DATE) from %PREFIX%MESSAGE, %PREFIX%GROUP_TO_MESSAGE " + "where %PREFIX%MESSAGE.MESSAGE_ID = %PREFIX%GROUP_TO_MESSAGE.MESSAGE_ID " + "and %PREFIX%GROUP_TO_MESSAGE.GROUP_KEY = ? " + "and %PREFIX%MESSAGE.REGION = ?) " + "and %PREFIX%GROUP_TO_MESSAGE.GROUP_KEY = ? " + "and m.REGION = ?)"), GET_GROUP_INFO("SELECT COMPLETE, LAST_RELEASED_SEQUENCE, CREATED_DATE, UPDATED_DATE" + " from %PREFIX%MESSAGE_GROUP where GROUP_KEY = ? and REGION=?"), GET_MESSAGE( "SELECT MESSAGE_ID, CREATED_DATE, MESSAGE_BYTES from %PREFIX%MESSAGE where MESSAGE_ID=? and REGION=?"), GET_GROUP_CREATED_DATE("SELECT CREATED_DATE from %PREFIX%MESSAGE_GROUP where GROUP_KEY=? and REGION=?"), GET_MESSAGE_COUNT("SELECT COUNT(MESSAGE_ID) from %PREFIX%MESSAGE where REGION=?"), DELETE_MESSAGE("DELETE from %PREFIX%MESSAGE where MESSAGE_ID=? and REGION=?"), CREATE_MESSAGE("INSERT into %PREFIX%MESSAGE(MESSAGE_ID, REGION, CREATED_DATE, MESSAGE_BYTES)" + " values (?, ?, ?, ?)"), COUNT_ALL_GROUPS("SELECT COUNT(GROUP_KEY) from %PREFIX%MESSAGE_GROUP where REGION=?"), COMPLETE_GROUP( "UPDATE %PREFIX%MESSAGE_GROUP set UPDATED_DATE=?, COMPLETE=1 where GROUP_KEY=? and REGION=?"), UPDATE_LAST_RELEASED_SEQUENCE( "UPDATE %PREFIX%MESSAGE_GROUP set UPDATED_DATE=?, LAST_RELEASED_SEQUENCE=? where GROUP_KEY=? and REGION=?"), DELETE_MESSAGE_GROUP("DELETE from %PREFIX%MESSAGE_GROUP where GROUP_KEY=? and REGION=?"), CREATE_GROUP_TO_MESSAGE( "INSERT into %PREFIX%GROUP_TO_MESSAGE" + "(GROUP_KEY, MESSAGE_ID, REGION)" + " values (?, ?, ?)"), UPDATE_GROUP("UPDATE %PREFIX%MESSAGE_GROUP set UPDATED_DATE=? where GROUP_KEY=? and REGION=?"), LIST_GROUP_KEYS("SELECT distinct GROUP_KEY as CREATED from %PREFIX%MESSAGE_GROUP where REGION=?"); private String sql; Query(String sql) { this.sql = sql; } public String getSql() { return this.sql; } } /** * The name of the message header that stores a flag to indicate that the message has been saved. This is an * optimization for the put method. * @deprecated since 5.0. This constant isn't used any more. */ @Deprecated public static final String SAVED_KEY = JdbcMessageStore.class.getSimpleName() + ".SAVED"; /** * The name of the message header that stores a timestamp for the time the message was inserted. * @deprecated since 5.0. This constant isn't used any more. */ @Deprecated public static final String CREATED_DATE_KEY = JdbcMessageStore.class.getSimpleName() + ".CREATED_DATE"; private final MessageMapper mapper = new MessageMapper(); private volatile String region = "DEFAULT"; private volatile String tablePrefix = DEFAULT_TABLE_PREFIX; private final JdbcOperations jdbcTemplate; private volatile DeserializingConverter deserializer; private volatile SerializingConverter serializer; private volatile LobHandler lobHandler = new DefaultLobHandler(); private volatile Map<Query, String> queryCache = new HashMap<Query, String>(); /** * Create a {@link MessageStore} with all mandatory properties. * @param dataSource a {@link DataSource} */ public JdbcMessageStore(DataSource dataSource) { this(new JdbcTemplate(dataSource)); } /** * Create a {@link MessageStore} with all mandatory properties. * @param jdbcOperations a {@link JdbcOperations} * @since 4.3.9 */ public JdbcMessageStore(JdbcOperations jdbcOperations) { Assert.notNull(jdbcOperations, "'dataSource' must not be null"); this.jdbcTemplate = jdbcOperations; this.deserializer = new DeserializingConverter(); this.serializer = new SerializingConverter(); } /** * Public setter for the table prefix property. This will be prefixed to all the table names before queries are * executed. Defaults to {@link #DEFAULT_TABLE_PREFIX}. * * @param tablePrefix the tablePrefix to set */ public void setTablePrefix(String tablePrefix) { this.tablePrefix = tablePrefix; } /** * A unique grouping identifier for all messages persisted with this store. Using multiple regions allows the store * to be partitioned (if necessary) for different purposes. Defaults to <code>DEFAULT</code>. * * @param region the region name to set */ public void setRegion(String region) { Assert.hasText(region, "Region must not be null or empty."); this.region = region; } /** * Override the {@link LobHandler} that is used to create and unpack large objects in SQL queries. The default is * fine for almost all platforms, but some Oracle drivers require a native implementation. * * @param lobHandler a {@link LobHandler} */ public void setLobHandler(LobHandler lobHandler) { this.lobHandler = lobHandler; } /** * A converter for serializing messages to byte arrays for storage. * * @param serializer the serializer to set */ @SuppressWarnings("unchecked") public void setSerializer(Serializer<? super Message<?>> serializer) { this.serializer = new SerializingConverter((Serializer<Object>) serializer); } /** * A converter for deserializing byte arrays to messages. * * @param deserializer the deserializer to set */ @SuppressWarnings({ "unchecked", "rawtypes" }) public void setDeserializer(Deserializer<? extends Message<?>> deserializer) { this.deserializer = new DeserializingConverter((Deserializer) deserializer); } @Override public Message<?> removeMessage(UUID id) { Message<?> message = getMessage(id); if (message == null) { return null; } int updated = this.jdbcTemplate.update(getQuery(Query.DELETE_MESSAGE), getKey(id), this.region); if (updated != 0) { return message; } return null; } @Override @ManagedAttribute public long getMessageCount() { return this.jdbcTemplate.queryForObject(getQuery(Query.GET_MESSAGE_COUNT), Long.class, this.region); } @Override public Message<?> getMessage(UUID id) { List<Message<?>> list = this.jdbcTemplate.query(getQuery(Query.GET_MESSAGE), this.mapper, getKey(id), this.region); if (list.isEmpty()) { return null; } return list.get(0); } @Override public MessageMetadata getMessageMetadata(UUID id) { List<MessageMetadata> list = this.jdbcTemplate.query(getQuery(Query.GET_MESSAGE), (rs, rn) -> { MessageMetadata messageMetadata = new MessageMetadata(UUID.fromString(rs.getString("MESSAGE_ID"))); messageMetadata.setTimestamp(rs.getTimestamp("CREATED_DATE").getTime()); return messageMetadata; }, getKey(id), this.region); if (list.isEmpty()) { return null; } return list.get(0); } @Override @SuppressWarnings("unchecked") public <T> Message<T> addMessage(final Message<T> message) { UUID id = message.getHeaders().getId(); final String messageId = getKey(id); final byte[] messageBytes = this.serializer.convert(message); if (logger.isDebugEnabled()) { logger.debug("Inserting message with id key=" + messageId); } try { this.jdbcTemplate.update(getQuery(Query.CREATE_MESSAGE), ps -> { ps.setString(1, messageId); ps.setString(2, this.region); ps.setTimestamp(3, new Timestamp(System.currentTimeMillis())); this.lobHandler.getLobCreator().setBlobAsBytes(ps, 4, messageBytes); }); } catch (DuplicateKeyException e) { if (logger.isDebugEnabled()) { logger.debug("The Message with id [" + id + "] already exists.\n" + "Ignoring INSERT and SELECT existing..."); } return (Message<T>) getMessage(id); } return message; } @Override public void addMessagesToGroup(Object groupId, Message<?>... messages) { final String groupKey = getKey(groupId); boolean groupNotExist = this.jdbcTemplate.queryForObject(this.getQuery(Query.GROUP_EXISTS), Integer.class, groupKey, this.region) < 1; final Timestamp updatedDate = new Timestamp(System.currentTimeMillis()); final Timestamp createdDate = groupNotExist ? updatedDate : this.jdbcTemplate.queryForObject(getQuery(Query.GET_GROUP_CREATED_DATE), Timestamp.class, groupKey, this.region); if (groupNotExist) { try { doCreateMessageGroup(groupKey, createdDate); } catch (DuplicateKeyException e) { logger.warn("Lost race to create group; attempting update instead", e); doUpdateMessageGroup(groupKey, updatedDate); } } else { doUpdateMessageGroup(groupKey, updatedDate); } for (Message<?> message : messages) { addMessage(message); } this.jdbcTemplate.batchUpdate(getQuery(Query.CREATE_GROUP_TO_MESSAGE), Arrays.asList(messages), 100, (ps, messageToAdd) -> { String messageId = getKey(messageToAdd.getHeaders().getId()); if (logger.isDebugEnabled()) { logger.debug( "Inserting message with id key=" + messageId + " and created date=" + createdDate); } ps.setString(1, groupKey); ps.setString(2, messageId); ps.setString(3, JdbcMessageStore.this.region); }); } @Override @ManagedAttribute public int getMessageGroupCount() { return this.jdbcTemplate.queryForObject(getQuery(Query.COUNT_ALL_GROUPS), Integer.class, this.region); } @Override @ManagedAttribute public int getMessageCountForAllMessageGroups() { return this.jdbcTemplate.queryForObject(getQuery(Query.COUNT_ALL_MESSAGES_IN_GROUPS), Integer.class, this.region); } @Override @ManagedAttribute public int messageGroupSize(Object groupId) { String key = getKey(groupId); return this.jdbcTemplate.queryForObject(getQuery(Query.COUNT_ALL_MESSAGES_IN_GROUP), Integer.class, key, this.region); } @Override public MessageGroup getMessageGroup(Object groupId) { String key = getKey(groupId); final AtomicReference<Date> createDate = new AtomicReference<Date>(); final AtomicReference<Date> updateDate = new AtomicReference<Date>(); final AtomicReference<Boolean> completeFlag = new AtomicReference<Boolean>(); final AtomicReference<Integer> lastReleasedSequenceRef = new AtomicReference<Integer>(); this.jdbcTemplate.query(getQuery(Query.GET_GROUP_INFO), rs -> { updateDate.set(rs.getTimestamp("UPDATED_DATE")); createDate.set(rs.getTimestamp("CREATED_DATE")); completeFlag.set(rs.getInt("COMPLETE") > 0); lastReleasedSequenceRef.set(rs.getInt("LAST_RELEASED_SEQUENCE")); }, key, this.region); if (createDate.get() == null && updateDate.get() == null) { return new SimpleMessageGroup(groupId); } MessageGroup messageGroup = getMessageGroupFactory().create(this, groupId, createDate.get().getTime(), completeFlag.get()); messageGroup.setLastModified(updateDate.get().getTime()); messageGroup.setLastReleasedMessageSequenceNumber(lastReleasedSequenceRef.get()); return messageGroup; } @Override public void removeMessagesFromGroup(Object groupId, Collection<Message<?>> messages) { Assert.notNull(groupId, "'groupId' must not be null"); Assert.notNull(messages, "'messages' must not be null"); final String groupKey = getKey(groupId); if (logger.isDebugEnabled()) { logger.debug("Removing messages from group with group key=" + groupKey); } this.jdbcTemplate.batchUpdate(getQuery(Query.REMOVE_MESSAGE_FROM_GROUP), messages, getRemoveBatchSize(), (ps, messageToRemove) -> { ps.setString(1, groupKey); ps.setString(2, getKey(messageToRemove.getHeaders().getId())); ps.setString(3, JdbcMessageStore.this.region); }); this.jdbcTemplate.batchUpdate(getQuery(Query.DELETE_MESSAGE), messages, getRemoveBatchSize(), (ps, messageToRemove) -> { ps.setString(1, getKey(messageToRemove.getHeaders().getId())); ps.setString(2, JdbcMessageStore.this.region); }); this.updateMessageGroup(groupKey); } @Override public void removeMessageGroup(Object groupId) { final String groupKey = getKey(groupId); for (UUID messageIds : this.getMessageIdsForGroup(groupId)) { this.removeMessage(messageIds); } this.jdbcTemplate.update(getQuery(Query.REMOVE_GROUP_TO_MESSAGE_JOIN), ps -> { if (logger.isDebugEnabled()) { logger.debug("Removing relationships for the group with group key=" + groupKey); } ps.setString(1, groupKey); ps.setString(2, JdbcMessageStore.this.region); }); this.jdbcTemplate.update(getQuery(Query.DELETE_MESSAGE_GROUP), ps -> { if (logger.isDebugEnabled()) { logger.debug("Marking messages with group key=" + groupKey); } ps.setString(1, groupKey); ps.setString(2, JdbcMessageStore.this.region); }); } @Override public void completeGroup(Object groupId) { final long updatedDate = System.currentTimeMillis(); final String groupKey = getKey(groupId); this.jdbcTemplate.update(getQuery(Query.COMPLETE_GROUP), ps -> { if (logger.isDebugEnabled()) { logger.debug("Completing MessageGroup: " + groupKey); } ps.setTimestamp(1, new Timestamp(updatedDate)); ps.setString(2, groupKey); ps.setString(3, JdbcMessageStore.this.region); }); } @Override public void setLastReleasedSequenceNumberForGroup(Object groupId, final int sequenceNumber) { Assert.notNull(groupId, "'groupId' must not be null"); final long updatedDate = System.currentTimeMillis(); final String groupKey = getKey(groupId); this.jdbcTemplate.update(getQuery(Query.UPDATE_LAST_RELEASED_SEQUENCE), ps -> { if (logger.isDebugEnabled()) { logger.debug("Updating the sequence number of the last released Message in the MessageGroup: " + groupKey); } ps.setTimestamp(1, new Timestamp(updatedDate)); ps.setInt(2, sequenceNumber); ps.setString(3, groupKey); ps.setString(4, JdbcMessageStore.this.region); }); this.updateMessageGroup(groupKey); } @Override public Message<?> pollMessageFromGroup(Object groupId) { String key = getKey(groupId); Message<?> polledMessage = this.doPollForMessage(key); if (polledMessage != null) { this.removeMessagesFromGroup(groupId, polledMessage); } return polledMessage; } @Override public Message<?> getOneMessageFromGroup(Object groupId) { return doPollForMessage(getKey(groupId)); } @Override public Collection<Message<?>> getMessagesForGroup(Object groupId) { return this.jdbcTemplate.query(getQuery(Query.LIST_MESSAGES_BY_GROUP_KEY), this.mapper, getKey(groupId), this.region); } @Override public Iterator<MessageGroup> iterator() { final Iterator<String> iterator = this.jdbcTemplate .query(getQuery(Query.LIST_GROUP_KEYS), new SingleColumnRowMapper<String>(), this.region) .iterator(); return new Iterator<MessageGroup>() { @Override public boolean hasNext() { return iterator.hasNext(); } @Override public MessageGroup next() { return getMessageGroup(iterator.next()); } @Override public void remove() { throw new UnsupportedOperationException("Cannot remove MessageGroup from this iterator."); } }; } /** * Replace patterns in the input to produce a valid SQL query. This implementation lazily initializes a * simple map-based cache, only replacing the table prefix on the first access to a named query. Further * accesses will be resolved from the cache. * * @param base the SQL query to be transformed * @return a transformed query with replacements */ protected String getQuery(Query base) { String query = this.queryCache.get(base); if (query == null) { query = StringUtils.replace(base.getSql(), "%PREFIX%", this.tablePrefix); this.queryCache.put(base, query); } return query; } /** * To be used to get a reference to JdbcOperations * in case this class is subclassed * * @return the JdbcOperations implementation */ protected JdbcOperations getJdbcOperations() { return this.jdbcTemplate; } /** * This method executes a call to the DB to get the oldest Message in the MessageGroup * Override this method if need to. For example if your DB supports advanced function such as FIRST etc. * @param groupIdKey String representation of message group ID * @return a message; could be null if query produced no Messages */ protected Message<?> doPollForMessage(String groupIdKey) { List<Message<?>> messages = this.jdbcTemplate.query(getQuery(Query.POLL_FROM_GROUP), this.mapper, groupIdKey, this.region, groupIdKey, this.region); Assert.state(messages.size() < 2, () -> "The query must return zero or 1 row; got " + messages.size() + " rows"); if (messages.size() > 0) { return messages.get(0); } return null; } private void doCreateMessageGroup(final String groupKey, final Timestamp createdDate) { this.jdbcTemplate.update(getQuery(Query.CREATE_MESSAGE_GROUP), ps -> { if (logger.isDebugEnabled()) { logger.debug("Creating message group with id key=" + groupKey + " and created date=" + createdDate); } ps.setString(1, groupKey); ps.setString(2, JdbcMessageStore.this.region); ps.setTimestamp(3, createdDate); ps.setTimestamp(4, createdDate); }); } private void doUpdateMessageGroup(final String groupKey, final Timestamp updatedDate) { this.jdbcTemplate.update(getQuery(Query.UPDATE_MESSAGE_GROUP), ps -> { if (logger.isDebugEnabled()) { logger.debug("Updating message group with id key=" + groupKey + " and updated date=" + updatedDate); } ps.setTimestamp(1, updatedDate); ps.setString(2, groupKey); ps.setString(3, JdbcMessageStore.this.region); }); } private void updateMessageGroup(final String groupId) { this.jdbcTemplate.update(getQuery(Query.UPDATE_GROUP), ps -> { if (logger.isDebugEnabled()) { logger.debug("Updating MessageGroup: " + groupId); } ps.setTimestamp(1, new Timestamp(System.currentTimeMillis())); ps.setString(2, groupId); ps.setString(3, JdbcMessageStore.this.region); }); } private List<UUID> getMessageIdsForGroup(Object groupId) { String key = getKey(groupId); final List<UUID> messageIds = new ArrayList<UUID>(); this.jdbcTemplate.query(getQuery(Query.LIST_MESSAGEIDS_BY_GROUP_KEY), (RowCallbackHandler) rs -> messageIds.add(UUID.fromString(rs.getString(1))), key, this.region); return messageIds; } private String getKey(Object input) { return input == null ? null : UUIDConverter.getUUID(input).toString(); } /** * Convenience class to be used to unpack a message from a result set row. Uses column named in the result set to * extract the required data, so that select clause ordering is unimportant. * * @author Dave Syer */ private class MessageMapper implements RowMapper<Message<?>> { @Override public Message<?> mapRow(ResultSet rs, int rowNum) throws SQLException { byte[] messageBytes = JdbcMessageStore.this.lobHandler.getBlobAsBytes(rs, "MESSAGE_BYTES"); return (Message<?>) JdbcMessageStore.this.deserializer.convert(messageBytes); } } }