/** Modifies events in-place. */
@Override
public Event intercept(Event event) {
Map<String, String> headers = event.getHeaders();
if (preserveExisting && headers.containsKey(key)) {
return event;
}
if (period >= 0) {
if (period == 0 || System.currentTimeMillis() > this.nextheaderscan) {
try {
String tmpValue = readHeader(file);
if (tmpValue != value) {
logger.debug(String.format("New CSV Header for file %s = %s", file, value));
value = tmpValue;
}
} catch (FlumeException e) {
logger.error(String.format("Error reading new CSV Header, keeping old one = %s", value));
}
calcNextheaderscan();
}
}
if (value != null) {
headers.put(key, value);
}
return event;
}
private void calcNextheaderscan() {
this.nextheaderscan = System.currentTimeMillis() + TimeUnit.SECONDS.toMillis(period);
}