public void process(Exchange exchange) throws Exception {
// store any existing file header which we want to keep and propagate
final String existing = exchange.getIn().getHeader(Exchange.FILE_NAME, String.class);
// create the target file name
String target = createFileName(exchange);
// use lock for same file name to avoid concurrent writes to the same file
// for example when you concurrently append to the same file
Lock lock;
synchronized (locks) {
lock = locks.get(target);
if (lock == null) {
lock = new ReentrantLock();
locks.put(target, lock);
}
}
lock.lock();
try {
processExchange(exchange, target);
} finally {
// do not remove as the locks cache has an upper bound
// this ensure the locks is appropriate reused
lock.unlock();
// and remove the write file name header as we only want to use it once (by design)
exchange.getIn().removeHeader(Exchange.OVERRULE_FILE_NAME);
// and restore existing file name
exchange.getIn().setHeader(Exchange.FILE_NAME, existing);
}
}
@Override
public Transformer put(TransformerKey key, Transformer transformer) {
// at first we must see if the key already exists and then replace it back, so it stays the same
// spot
Transformer answer = staticMap.remove(key);
if (answer != null) {
// replace existing
staticMap.put(key, transformer);
return answer;
}
answer = super.remove(key);
if (answer != null) {
// replace existing
super.put(key, transformer);
return answer;
}
// we want endpoints to be static if they are part of setting up or starting routes
if (context.isSetupRoutes() || context.isStartingRoutes()) {
answer = staticMap.put(key, transformer);
} else {
answer = super.put(key, transformer);
}
return answer;
}
/** Purges the cache */
@Override
public void purge() {
// only purge the dynamic part
super.clear();
}
@Override
public void clear() {
staticMap.clear();
super.clear();
}