/// <summary> This initialization is used by all resource
/// loaders and must be called to set up common
/// properties shared by all resource loaders
/// </summary>
/// <param name="rs">
/// </param>
/// <param name="configuration">
/// </param>
public virtual void CommonInit(IRuntimeServices rs, ExtendedProperties configuration)
{
this.rsvc = rs;
this.log = rsvc.Log;
/*
* these two properties are not required for all loaders.
* For example, for ClasspathLoader, what would cache mean?
* so adding default values which I think are the safest
*
* don't cache, and modCheckInterval irrelevant...
*/
try
{
isCachingOn = configuration.GetBoolean("cache", false);
}
catch (System.Exception e)
{
isCachingOn = false;
string msg = "Exception parsing cache setting: " + configuration.GetString("cache");
log.Error(msg, e);
throw new VelocityException(msg, e);
}
try
{
modificationCheckInterval = configuration.GetLong("modificationCheckInterval", 0);
}
catch (System.Exception e)
{
modificationCheckInterval = 0;
string msg = "Exception parsing modificationCheckInterval setting: " + configuration.GetString("modificationCheckInterval");
log.Error(msg, e);
throw new VelocityException(msg, e);
}
/*
* this is a must!
*/
className = typeof(ResourceCacheImpl).FullName;
try
{
className = configuration.GetString("class", className);
}
catch (System.Exception e)
{
string msg = "Exception retrieving resource cache class name";
log.Error(msg, e);
throw new VelocityException(msg, e);
}
}
/// <summary> Check whether any given resource exists. This is not really
/// a very efficient test and it can and should be overridden in the
/// subclasses extending ResourceLoader.
///
/// </summary>
/// <param name="resourceName">The name of a resource.
/// </param>
/// <returns> true if a resource exists and can be accessed.
/// </returns>
/// <since> 1.6
/// </since>
public virtual bool ResourceExists(string resourceName)
{
System.IO.Stream is_Renamed = null;
try
{
is_Renamed = GetResourceStream(resourceName);
}
catch (ResourceNotFoundException e)
{
if (log.DebugEnabled)
{
log.Debug("Could not load resource '" + resourceName + "' from ResourceLoader " + this.GetType().FullName + ": ", e);
}
}
finally
{
try
{
if (is_Renamed != null)
{
is_Renamed.Close();
}
}
catch (System.Exception e)
{
if (log.ErrorEnabled)
{
string msg = "While closing InputStream for resource '" + resourceName + "' from ResourceLoader " + this.GetType().FullName;
log.Error(msg, e);
throw new VelocityException(msg, e);
}
}
}
return(is_Renamed != null);
}
/// <summary> Initialize the ResourceManager.
///
/// </summary>
/// <param name="rsvc"> The Runtime Services object which is associated with this Resource Manager.
///
/// </param>
/// <throws> Exception </throws>
public virtual void Initialize(IRuntimeServices rsvc)
{
lock (syncOjb)
{
if (isInit)
{
log.Debug("Re-initialization of ResourceLoader attempted and ignored.");
return;
}
ResourceLoader resourceLoader = null;
this.rsvc = rsvc;
log = rsvc.Log;
log.Trace("Default ResourceManager initializing. (" + this.GetType() + ")");
AssembleResourceLoaderInitializers();
for (IEnumerator it = sourceInitializerList.GetEnumerator(); it.MoveNext();)
{
/**
* Resource loader can be loaded either via class name or be passed
* in as an instance.
*/
ExtendedProperties configuration = (ExtendedProperties)it.Current;
string loaderClass = StringUtils.NullTrim(configuration.GetString("class"));
ResourceLoader loaderInstance = (ResourceLoader)configuration["instance"];
if (loaderInstance != null)
{
resourceLoader = loaderInstance;
}
else if (loaderClass != null)
{
resourceLoader = ResourceLoaderFactory.GetLoader(rsvc, loaderClass);
}
else
{
string msg = "Unable to find '" + configuration.GetString(RESOURCE_LOADER_IDENTIFIER) + ".resource.loader.class' specification in configuration." + " This is a critical value. Please adjust configuration.";
log.Error(msg);
throw new System.Exception(msg);
}
resourceLoader.CommonInit(rsvc, configuration);
resourceLoader.Init(configuration);
resourceLoaders.Add(resourceLoader);
}
/*
* now see if this is overridden by configuration
*/
logWhenFound = rsvc.GetBoolean(NVelocity.Runtime.RuntimeConstants.RESOURCE_MANAGER_LOGWHENFOUND, true);
/*
* now, is a global cache specified?
*/
string cacheClassName = rsvc.GetString(RuntimeConstants.RESOURCE_MANAGER_CACHE_CLASS);
object cacheObject = null;
if (!string.IsNullOrEmpty(cacheClassName))
{
try
{
cacheObject = System.Activator.CreateInstance(Type.GetType(cacheClassName.Replace(';', ',')));
}
catch (System.Exception cnfe)
{
string msg = "The specified class for ResourceCache (" + cacheClassName + ") does not exist or is not accessible to the current classloader.";
log.Error(msg, cnfe);
throw cnfe;
}
if (!(cacheObject is IResourceCache))
{
string msg = "The specified resource cache class (" + cacheClassName + ") must implement " + typeof(IResourceCache).FullName;
log.Error(msg);
throw new System.SystemException(msg);
}
}
/*
* if we didn't Get through that, just use the default.
*/
if (cacheObject == null)
{
cacheObject = new ResourceCacheImpl();
}
globalCache = (IResourceCache)cacheObject;
globalCache.Initialize(rsvc);
log.Trace("Default ResourceManager initialization complete.");
}
}
/// <summary> Gets the named resource. Returned class type corresponds to specified type (i.e. <code>Template</code> to <code>
/// RESOURCE_TEMPLATE</code>).
///
/// This method is now unsynchronized which requires that ResourceCache
/// implementations be thread safe (as the default is).
///
/// </summary>
/// <param name="resourceName"> The name of the resource to retrieve.
/// </param>
/// <param name="resourceType"> The type of resource (<code>RESOURCE_TEMPLATE</code>, <code>RESOURCE_CONTENT</code>, etc.).
/// </param>
/// <param name="encoding"> The character encoding to use.
///
/// </param>
/// <returns> Resource with the template parsed and ready.
///
/// </returns>
/// <throws> ResourceNotFoundException if template not found from any available source. </throws>
/// <throws> ParseErrorException if template cannot be parsed due to syntax (or other) Error. </throws>
/// <throws> Exception if a problem in parse </throws>
public virtual Resource GetResource(string resourceName, int resourceType, string encoding)
{
/*
* Check to see if the resource was placed in the cache.
* If it was placed in the cache then we will use
* the cached version of the resource. If not we
* will load it.
*
* Note: the type is included in the key to differentiate ContentResource
* (static content from #include) with a Template.
*/
string resourceKey = resourceType + resourceName;
Resource resource = globalCache.Get(resourceKey);
if (resource != null)
{
try
{
// avoids additional method call to refreshResource
if (resource.RequiresChecking())
{
/*
* both loadResource() and refreshResource() now return
* a new Resource instance when they are called
* (Put in the cache when appropriate) in order to allow
* several threads to parse the same template simultaneously.
* It is redundant work and will cause more garbage collection but the
* benefit is that it allows concurrent parsing and processing
* without race conditions when multiple requests try to
* refresh/load the same template at the same time.
*
* Another alternative is to limit template parsing/retrieval
* so that only one thread can parse each template at a time
* but that creates a scalability bottleneck.
*
* See VELOCITY-606, VELOCITY-595 and VELOCITY-24
*/
resource = RefreshResource(resource, encoding);
}
}
catch (ResourceNotFoundException)
{
/*
* something exceptional happened to that resource
* this could be on purpose,
* so clear the cache and try again
*/
globalCache.Remove(resourceKey);
return(GetResource(resourceName, resourceType, encoding));
}
catch (ParseErrorException pee)
{
log.Error("ResourceManager.getResource() exception", pee);
throw pee;
}
catch (System.SystemException re)
{
log.Error("ResourceManager.getResource() exception", re);
throw re;
}
catch (System.Exception e)
{
log.Error("ResourceManager.getResource() exception", e);
throw e;
}
}
else
{
try
{
/*
* it's not in the cache, so load it.
*/
resource = LoadResource(resourceName, resourceType, encoding);
if (resource.ResourceLoader.CachingOn)
{
globalCache.Put(resourceKey, resource);
}
}
catch (ResourceNotFoundException rnfe)
{
log.Error("ResourceManager : unable to find resource '" + resourceName + "' in any resource loader.");
throw rnfe;
}
catch (ParseErrorException pee)
{
log.Error("ResourceManager.getResource() parse exception", pee);
throw pee;
}
catch (System.SystemException re)
{
log.Error("ResourceManager.getResource() load exception", re);
throw re;
}
catch (System.Exception e)
{
log.Error("ResourceManager.getResource() exception new", e);
throw e;
}
}
return(resource);
}
