private WebSocketChannelDTO getChannel(int channelId) throws SQLException, DatabaseException {
if (!channelCache.containsKey(channelId)) {
WebSocketChannelDTO criteria = new WebSocketChannelDTO();
criteria.id = channelId;
List<WebSocketChannelDTO> channels = getChannels(criteria);
if (channels.size() == 1) {
channelCache.put(channelId, channels.get(0));
} else {
throw new SQLException("Channel '" + channelId + "' not found!");
}
}
return (WebSocketChannelDTO) channelCache.get(channelId);
}
private List<WebSocketChannelDTO> buildChannelDTOs(ResultSet rs) throws SQLException {
ArrayList<WebSocketChannelDTO> channels = new ArrayList<>();
try {
while (rs.next()) {
WebSocketChannelDTO channel = new WebSocketChannelDTO();
channel.id = rs.getInt("channel_id");
channel.host = rs.getString("host");
channel.port = rs.getInt("port");
channel.url = rs.getString("url");
channel.startTimestamp = rs.getTimestamp("start_timestamp").getTime();
Time endTs = rs.getTime("end_timestamp");
channel.endTimestamp = (endTs != null) ? endTs.getTime() : null;
channel.historyId = rs.getInt("history_id");
channels.add(channel);
}
} finally {
rs.close();
}
channels.trimToSize();
return channels;
}
public void insertOrUpdateChannel(WebSocketChannelDTO channel) throws DatabaseException {
try {
synchronized (this) {
if (getConnection().isClosed()) {
// temporarily buffer channels and insert/update later
channelsBuffer.offer(channel);
return;
}
do {
PreparedStatement stmt;
boolean addIdOnSuccess = false;
// first, find out if already inserted
if (channelIds.contains(channel.id)) {
// proceed with update
stmt = psUpdateChannel;
} else {
// proceed with insert
stmt = psInsertChannel;
addIdOnSuccess = true;
logger.info("insert channel: " + channel.toString());
}
if (logger.isDebugEnabled()) {
logger.debug("url (length " + channel.url.length() + "):" + channel.url);
}
stmt.setString(1, channel.host);
stmt.setInt(2, channel.port);
stmt.setString(3, channel.url);
stmt.setTimestamp(
4, (channel.startTimestamp != null) ? new Timestamp(channel.startTimestamp) : null);
stmt.setTimestamp(
5, (channel.endTimestamp != null) ? new Timestamp(channel.endTimestamp) : null);
stmt.setNull(6, Types.INTEGER);
stmt.setInt(7, channel.id);
stmt.execute();
if (addIdOnSuccess) {
channelIds.add(channel.id);
}
if (channel.historyId != null) {
psUpdateHistoryFk.setInt(1, channel.historyId);
psUpdateHistoryFk.setInt(2, channel.id);
try {
psUpdateHistoryFk.execute();
} catch (SQLException e) {
// safely ignore this exception
// on shutdown, the history table is cleaned before
// WebSocket channels are closed and updated
if (logger.isDebugEnabled()) {
logger.debug(e.getMessage(), e);
}
}
}
channel = channelsBuffer.poll();
} while (channel != null);
}
} catch (SQLException e) {
throw new DatabaseException(e);
}
}