/**
* Load any available events from the database up to the configured maximum.
*
* @param criteria An event containing the event-selection criteria.
* @return The next available event on the queue.
* @exception FrameworkException Thrown on errors.
*/
private void loadFromDatabase(Event criteria) throws FrameworkException {
Debug.log(Debug.MSG_STATUS, "QUEUE OPERATION: Loading events from database into queue ...");
if (!StringUtils.hasValue(criteria.channelName)) {
throw new FrameworkException(
"ERROR: Event channel name is a required queue search criteria.");
}
Connection dbConn = null;
PreparedStatement ps = null;
long startTime = -1;
if (Debug.isLevelEnabled(Debug.BENCHMARK)) startTime = System.currentTimeMillis();
try {
dbConn = DBConnectionPool.getInstance().acquireConnection();
if (Debug.isLevelEnabled(Debug.DB_DATA))
Debug.log(Debug.DB_DATA, "\n" + LINE + "\nExecuting SQL:\n" + QUERY_EVENT_SQL);
if (Debug.isLevelEnabled(Debug.DB_DATA))
Debug.log(
Debug.DB_DATA, "Criteria used in query against database:\n" + criteria.describe());
ps = dbConn.prepareStatement(QUERY_EVENT_SQL);
ps.setString(1, criteria.channelName);
ResultSet rs = ps.executeQuery();
for (int counter = 0; (counter < maxDatabaseEventLoadSize) && rs.next(); counter++) {
Event event = new Event();
event.channelName = rs.getString(CHANNEL_NAME_COL);
event.id = rs.getInt(ID_COL);
event.message = DBLOBUtils.getCLOB(rs, MESSAGE_COL);
if (Debug.isLevelEnabled(Debug.MSG_LIFECYCLE))
Debug.log(Debug.MSG_LIFECYCLE, "Event contents:\n" + event.message);
event.arrivalTime = rs.getTimestamp(ARRIVAL_TIME_COL);
event.errorStatus = rs.getString(ERROR_STATUS_COL);
event.errorCount = rs.getInt(ERROR_COUNT_COL);
event.lastErrorMessage = rs.getString(LAST_ERROR_MESSAGE_COL);
event.lastErrorTime = rs.getTimestamp(LAST_ERROR_TIME_COL);
// Add item to in-memory buffer.
if (Debug.isLevelEnabled(Debug.MSG_STATUS))
Debug.log(
Debug.MSG_STATUS,
"Adding event [" + event.describe() + "] to in-memory queue buffer.");
queue.add(event);
if (Debug.isLevelEnabled(Debug.MSG_STATUS))
Debug.log(Debug.MSG_STATUS, "In-memory queue buffer size [" + queue.size() + "].");
}
if (Debug.isLevelEnabled(Debug.DB_DATA)) Debug.log(Debug.DB_DATA, "\n" + LINE);
} catch (SQLException sqle) {
throw new DatabaseException(
"ERROR: Could not execute SQL statement:\n" + DBInterface.getSQLErrorMessage(sqle));
} catch (Exception e) {
throw new DatabaseException("ERROR: Could not execute SQL statement:\n" + e.toString());
} finally {
releaseDatabaseResources(dbConn, ps);
if (Debug.isLevelEnabled(Debug.BENCHMARK) && (startTime > 0)) {
long stopTime = System.currentTimeMillis();
Debug.log(
Debug.BENCHMARK,
"ELAPSED TIME ["
+ (stopTime - startTime)
+ "] msec: "
+ "SQL: Time to load event(s) from PersistentEvent database table.");
}
}
}
/**
* Update the given event as indicated.
*
* @param event The event to update.
* @param eventStatus The event delivery status.
* @exception FrameworkException Thrown on errors.
*/
public void update(Event event, EventStatus eventStatus) throws FrameworkException {
if (Debug.isLevelEnabled(Debug.MSG_STATUS))
Debug.log(
Debug.MSG_STATUS,
"QUEUE OPERATION: Updating database queue using event status ["
+ eventStatus.name
+ "] ...");
// If no consumers were available, the event delivery wasn't attempted so leave
// the queue in its current state.
if (eventStatus == EventStatus.NO_CONSUMERS_AVAILABLE) {
Debug.log(
Debug.MSG_STATUS, "Skipping queue update, as no consumers were available to process it.");
return;
}
Connection dbConn = null;
PreparedStatement ps = null;
long startTime = -1;
if (Debug.isLevelEnabled(Debug.BENCHMARK)) startTime = System.currentTimeMillis();
try {
dbConn = DBConnectionPool.getInstance().acquireConnection();
if (eventStatus == EventStatus.DELIVERY_SUCCESSFUL) {
// If the event was successfully delivered, update status in database to delivered.
if (Debug.isLevelEnabled(Debug.DB_DATA))
Debug.log(Debug.DB_DATA, "\n" + LINE + "\nExecuting SQL:\n" + UPDATE_EVENT_SUCCESS_SQL);
ps = dbConn.prepareStatement(UPDATE_EVENT_SUCCESS_SQL);
java.sql.Timestamp ts = new java.sql.Timestamp(System.currentTimeMillis());
ps.setTimestamp(1, ts);
ps.setString(2, event.channelName);
ps.setInt(3, event.id);
} else if (eventStatus == EventStatus.DELIVERY_FAILED) {
// If the event delivery failed, we mark it as failed in the database.
if (Debug.isLevelEnabled(Debug.DB_DATA))
Debug.log(Debug.DB_DATA, "\n" + LINE + "\nExecuting SQL:\n" + UPDATE_EVENT_ERROR_SQL);
// Truncate error message if it's larger than database column.
if ((event.lastErrorMessage != null)
&& (event.lastErrorMessage.length() > MAX_ERROR_MESSAGE_LENGTH))
event.lastErrorMessage = event.lastErrorMessage.substring(0, MAX_ERROR_MESSAGE_LENGTH);
event.lastErrorTime = new java.sql.Timestamp(System.currentTimeMillis());
ps = dbConn.prepareStatement(UPDATE_EVENT_ERROR_SQL);
ps.setTimestamp(1, event.lastErrorTime);
ps.setString(2, event.lastErrorMessage);
ps.setString(3, event.channelName);
ps.setInt(4, event.id);
} else {
throw new FrameworkException(
"ERROR: Invalid event update type [" + eventStatus.name + "].");
}
if (Debug.isLevelEnabled(Debug.DB_DATA))
Debug.log(Debug.DB_DATA, "Event being operated on in database:\n" + event.describe());
int numRows = ps.executeUpdate();
if (numRows > 1) {
String errMsg = "Execution of update SQL statement affected [" + numRows + "] rows.";
Debug.error(errMsg);
throw new FrameworkException(errMsg);
}
DBConnectionPool.getInstance().commit(dbConn);
if (Debug.isLevelEnabled(Debug.DB_DATA))
Debug.log(Debug.DB_DATA, "Successfully committed SQL operation.\n" + LINE);
// At this point, the event should be removed from the in-memory buffer of events as well,
// irrespective of processing outcome.
if (Debug.isLevelEnabled(Debug.MSG_STATUS))
Debug.log(
Debug.MSG_STATUS,
"Removing event [" + event.describe() + "] from in-memory queue buffer.");
boolean removed = queue.remove(event);
if (Debug.isLevelEnabled(Debug.MSG_STATUS))
Debug.log(
Debug.MSG_STATUS,
"Event removed? ["
+ removed
+ "]. In-memory queue buffer size ["
+ queue.size()
+ "].");
} catch (SQLException sqle) {
throw new DatabaseException(
"ERROR: Could not execute SQL statement:\n" + DBInterface.getSQLErrorMessage(sqle));
} catch (Exception e) {
throw new DatabaseException("ERROR: Could not execute SQL statement:\n" + e.toString());
} finally {
releaseDatabaseResources(dbConn, ps);
if (Debug.isLevelEnabled(Debug.BENCHMARK) && (startTime > 0)) {
long stopTime = System.currentTimeMillis();
Debug.log(
Debug.BENCHMARK,
"ELAPSED TIME ["
+ (stopTime - startTime)
+ "] msec: "
+ "SQL: Time to update event in PersistentEvent database table.");
}
}
}