/**
* Constructs a SessionCachePostProcessor with a specified cache and cache key, and an optional property listener
* and property name.
*
* @param cache cache that receives the retrieved data.
* @param cacheKey cache key to place the retrieved data under.
* @param absentResourceList the absent resource list to update.
* @param resourceID the resource ID to use in the absent resource list.
* @param propertyListener property listener to notify when the data is available. Can be null.
* @param propertyName property name to use for the property event when the data is available. Can be null.
*/
public SessionCacheRetrievalPostProcessor(SessionCache cache, Object cacheKey,
AbsentResourceList absentResourceList, long resourceID,
PropertyChangeListener propertyListener, String propertyName)
{
if (cache == null)
{
String message = Logging.getMessage("nullValue.CacheIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
if (cacheKey == null)
{
String message = Logging.getMessage("nullValue.CacheKeyIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
this.cache = cache;
this.cacheKey = cacheKey;
this.absentResourceList = absentResourceList;
this.resourceID = resourceID;
this.propertyListener = propertyListener;
this.propertyName = propertyName;
}
/**
* Retrieves the contents of a specified {@link java.net.URL}. If successful, this places the URL
* contents in a specified session cache with a specified key. This either marks the resource as available or
* missing, depending on whether the retrieval succeeds or fails. Finally, this optionally notifies the caller that
* the retrieval has succeeded by firing a property change event. If either the property listener or property name
* are null, that functionality is disabled.
*
* @param url the URL contents to retrieve.
* @param cache the cache which receives the retrieved data.
* @param cacheKey the cache key which identifies where the retrieved data is placed in the session
* cache.
* @param absentResourceList the absent resource list to update.
* @param resourceID the resource ID to use in the absent resource list.
* @param propertyListener the property change listener which is fired when the retrieved data is available.
* @param propertyName the property name to fire when retrieved data is available.
*
* @throws ArgumentException if any of the url, retrieval service, cache, or cache key are null.
*/
public static void retrieveSessionData(java.net.URL url, SessionCache cache, Object cacheKey,
AbsentResourceList absentResourceList, long resourceID, PropertyChangeListener propertyListener,
String propertyName)
{
if (url == null)
{
String message = Logging.getMessage("nullValue.URLIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
if (cache == null)
{
String message = Logging.getMessage("nullValue.CacheIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
if (cacheKey == null)
{
String message = Logging.getMessage("nullValue.CacheKeyIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
if (WorldWind.getNetworkStatus().isHostUnavailable(url))
{
if (absentResourceList != null)
{
absentResourceList.markResourceAbsent(resourceID);
}
return;
}
SessionCacheRetrievalPostProcessor postProcessor = new SessionCacheRetrievalPostProcessor(cache, cacheKey,
absentResourceList, resourceID, propertyListener, propertyName);
postProcessor.setName(url.ToString());
Retriever retriever = URLRetriever.createRetriever(url, postProcessor);
try
{
retriever.call();
}
catch (Exception e)
{
String message = Logging.getMessage("layers.TiledImageLayer.ExceptionRetrievingResources", url.ToString());
Logging.logger().log(java.util.logging.Level.SEVERE, message, e);
}
}
/**
* Checks a session cache for a specified key, and if present attempts to interpret the cache entry as a {@link
* WMSCapabilities} document. If the key does not map to a Capabilities document for any reason, this attempts to
* asynchronously retrieve the Capabilities from a specified URL, and returns null.
*
* @param url the URL contents to retrieve.
* @param cache the session cache.
* @param cacheKey the key to identify the object in the session cache.
* @param absentResourceList the absent resource list to update.
* @param resourceID the resource ID to use in the absent resource list.
* @param propertyListener the property change listener which is fired when the retrieved data is available.
* @param propertyName the property name to fire when retrieved data is available.
*
* @return the Capabilities document in the session cache, or null if the document is not in the cache.
*
* @throws ArgumentException if either the url, retrieval service, cache or cache key are null.
*/
public static WMSCapabilities getOrRetrieveSessionCapabilities(java.net.URL url, SessionCache cache,
Object cacheKey, AbsentResourceList absentResourceList, long resourceID,
PropertyChangeListener propertyListener, String propertyName)
{
if (url == null)
{
String message = Logging.getMessage("nullValue.URLIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
if (cache == null)
{
String message = Logging.getMessage("nullValue.CacheIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
if (cacheKey == null)
{
String message = Logging.getMessage("nullValue.CacheKeyIsNull");
Logging.logger().severe(message);
throw new ArgumentException(message);
}
WMSCapabilities caps = getSessionCapabilities(cache, cacheKey, url.ToString());
if (caps != null)
{
return(caps);
}
retrieveSessionData(url, cache, cacheKey, absentResourceList, resourceID, propertyListener, propertyName);
// Try to get the caps after the retrieval attempt.
return(getSessionCapabilities(cache, cacheKey, url.ToString()));
}
