ro.isdc.wro.model.resource.support.change

Class ResourceWatcher

java.lang.Object

ro.isdc.wro.model.resource.support.change.ResourceWatcher

All Implemented Interfaces:

Destroyable

public class ResourceWatcher
extends Object
implements Destroyable

A runnable responsible for watching if any resources were changed and invalidate the cache entry for the group containing obsolete resources. This class is thread-safe.

Since:

1.4.8

Author:

Alex Objelean

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ResourceWatcher.Callback
static class	ResourceWatcher.CallbackSupport Default implementation of ResourceWatcher.Callback which does nothing by default.

Constructor Summary

Constructors

Constructor and Description
ResourceWatcher()

Method Summary

Methods

Modifier and Type	Method and Description
void	check(CacheKey cacheKey) Default constructor with a NoOP callback.
void	check(CacheKey cacheKey, ResourceWatcher.Callback callback) Check if resources from a group were changed.
void	destroy() Destroy this object or any other internal state created during initialization.
protected void	onException(Exception e) Invoked when exception occurs.
boolean	tryAsyncCheck(CacheKey cacheKey) Will try an asynchronous check if the async configuration is enabled.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ResourceWatcher

public ResourceWatcher()

Method Detail

check

public void check(CacheKey cacheKey)

Default constructor with a NoOP callback.

tryAsyncCheck

public boolean tryAsyncCheck(CacheKey cacheKey)

Will try an asynchronous check if the async configuration is enabled. If async check is not configured, a synchronous check will be performed. The async check assumes that the ResourceWatcherRequestHandler is enabled.

If the async check is not allowed (the request was not passed through WroFilter) - no check will be performed. This is important for use-cases when wro resource is included using a taglib which performs a wro api call directly, without being invoked through WroFilter.

Returns:

true if the actual check invocation was performed. This is important to decide if the resource change should be skipped or not.

check

public void check(CacheKey cacheKey,
         ResourceWatcher.Callback callback)

Check if resources from a group were changed. If a change is detected, the changeListener will be invoked.

Parameters:

cacheKey - the cache key which was requested. The key contains the groupName which has to be checked for changes.

onException

protected void onException(Exception e)

Invoked when exception occurs.

destroy

public void destroy()
             throws Exception

Description copied from interface: Destroyable

Destroy this object or any other internal state created during initialization.

Specified by:

destroy in interface Destroyable

Throws:

Exception - if the destroy operation failed.