public List<NotificationEntry> getNotifications(String username, String startId) {
try {
byte[] timeUUIDAsBytes = EMPTY_BYTE_ARRAY;
if (startId != null && startId.length() > 0) {
UUID uuid = UUIDUtil.fromString(startId);
final byte[] idAsBytes = UUIDUtil.toBytes(uuid);
timeUUIDAsBytes = getTimeUUIDFromID(username, idAsBytes);
if (timeUUIDAsBytes == null) {
timeUUIDAsBytes = EMPTY_BYTE_ARRAY;
}
}
Selector selector = Pelops.createSelector(TRENDOCEAN_POOL, TRENDOCEAN_KEYSPACE);
SlicePredicate columnPredicate =
Selector.newColumnsPredicate(timeUUIDAsBytes, EMPTY_BYTE_ARRAY, true, PAGE_SIZE);
List<SuperColumn> columns =
selector.getSuperColumnsFromRow(username, WALL_CF, columnPredicate, ConsistencyLevel.ONE);
List<NotificationEntry> notificationList = new ArrayList<NotificationEntry>(columns.size());
for (SuperColumn superColumn : columns) {
List<Column> wallEntryColumns = superColumn.getColumns();
String notificationId = null;
NotificationType notificationType = null;
String questionId = null;
String relatedUser = null;
long answerCount = -1L;
long time = 0;
for (Column notificationColumn : wallEntryColumns) {
String notificationColumnName = toString(notificationColumn.getName());
if (notificationColumnName.equals("_id")) {
notificationId = UUIDUtil.toUUID(notificationColumn.getValue()).toString();
long timeInMicroSeconds = notificationColumn.getTimestamp();
time = timeInMicroSeconds / 1000L;
} else if (notificationColumnName.equals("_type")) {
notificationType = NotificationType.fromId(toByte(notificationColumn));
} else if (notificationColumnName.equals("questionId")) {
questionId = toString(notificationColumn);
} else if (notificationColumnName.equals("relatedUser")) {
relatedUser = toString(notificationColumn);
} else if (notificationColumnName.equals("answerCount")) {
answerCount = toLong(notificationColumn);
} else {
logger.warn("Invalid notification column:{}", notificationColumnName);
}
}
NotificationEntry notificationEntry = new NotificationEntry();
notificationEntry.setId(notificationId);
notificationEntry.setTime(time);
notificationEntry.setNotificationType(notificationType);
notificationEntry.setQuestionId(questionId);
notificationList.add(notificationEntry);
notificationEntry.setUsername(relatedUser);
notificationEntry.setAnswerCount(answerCount);
}
return notificationList;
} catch (NotFoundException ex) {
return Collections.EMPTY_LIST;
} catch (Exception ex) {
logger.error("Can not get time uuid", ex);
throw new TrendOceanException(ex);
}
}
private byte[] getTimeUUIDFromID(String username, byte[] idAsBytes) {
try {
Selector selector = Pelops.createSelector(TRENDOCEAN_POOL, TRENDOCEAN_KEYSPACE);
Column column =
selector.getColumnFromRow(username, ID_TO_TIMEUUID_CF, idAsBytes, ConsistencyLevel.ONE);
byte[] timeUUIDAsBytes = column.getValue();
return timeUUIDAsBytes;
} catch (NotFoundException ex) {
return null;
} catch (Exception ex) {
logger.error("Can not get time uuid", ex);
throw new TrendOceanException(ex);
}
}