/**
* Refresh a single element.
*
* <p>Refreshes bypass the {@link BlockingCache} and act directly on the backing {@link Ehcache}.
* This way, {@link BlockingCache} gets can continue to return stale data while the refresh, which
* might be expensive, takes place.
*
* <p>If the element is absent it is created
*
* <p>Quiet methods are used if argument 1 is true, so that statistics are not affected, but note
* that replication will then not occur
*
* @param key
* @param quiet whether the backing cache is quietly updated or not, if true replication will not
* occur
* @return the refreshed Element
* @throws CacheException
* @since 1.6.1
*/
public Element refresh(Object key, boolean quiet) throws CacheException {
try {
Ehcache backingCache = getCache();
Element element = backingCache.getQuiet(key);
if (element != null) {
return refreshElement(element, backingCache, quiet);
} else {
// need to create
return get(key);
}
} catch (CacheException ce) {
throw ce;
} catch (Exception e) {
throw new CacheException(e.getMessage() + " on refresh with key " + key, e);
}
}
/**
* Refresh the elements of this cache.
*
* <p>Refreshes bypass the {@link BlockingCache} and act directly on the backing {@link Ehcache}.
* This way, {@link BlockingCache} gets can continue to return stale data while the refresh, which
* might be expensive, takes place.
*
* <p>Quiet methods are used if argument 0 is true, so that statistics are not affected, but note
* that replication will then not occur
*
* <p>Configure ehcache.xml to stop elements from being refreshed forever:
*
* <ul>
* <li>use timeToIdle to discard elements unused for a period of time
* <li>use timeToLive to discard elmeents that have existed beyond their allotted lifespan
* </ul>
*
* @param quiet whether the backing cache is quietly updated or not, if true replication will not
* occur
* @throws CacheException
* @since 1.6.1
*/
public void refresh(boolean quiet) throws CacheException {
Exception exception = null;
Object keyWithException = null;
// Refetch the entries
final Collection keys = getKeys();
if (LOG.isLoggable(Level.FINE)) {
LOG.fine(getName() + ": found " + keys.size() + " keys to refresh");
}
// perform the refresh
for (Iterator iterator = keys.iterator(); iterator.hasNext(); ) {
final Object key = iterator.next();
try {
Ehcache backingCache = getCache();
final Element element = backingCache.getQuiet(key);
if (element == null) {
if (LOG.isLoggable(Level.FINE)) {
LOG.fine(getName() + ": entry with key " + key + " has been removed - skipping it");
}
continue;
}
refreshElement(element, backingCache, quiet);
} catch (final Exception e) {
// Collect the exception and keep going.
// Throw the exception once all the entries have been refreshed
// If the refresh fails, keep the old element. It will simply become staler.
LOG.log(Level.WARNING, getName() + "Could not refresh element " + key, e);
exception = e;
}
}
if (exception != null) {
throw new CacheException(exception.getMessage() + " on refresh with key " + keyWithException);
}
}
