org.zkoss.util.resource
Class ResourceCache<K,V>

java.lang.Object
  org.zkoss.util.CacheMap<Object,Object>
      org.zkoss.util.resource.ResourceCache<K,V>

All Implemented Interfaces:

Serializable, Cloneable, Map<Object,Object>, Cache<Object,Object>

public class ResourceCache<K,V>
extends CacheMap<Object,Object>

Used to cache resources. To use this class, you have to implement Loader and then ResourceCache will use it to check whether a resource is gone, modified and load the resource.

Unlike CacheMap, it is thread-safe.

The default check period depends on the library property called org.zkoss.util.resource.checkPeriod (unit: second). If not specified, 5 seconds are assumed

Author:

tomyeh

See Also:

Serialized Form

Nested Class Summary

Nested classes/interfaces inherited from class org.zkoss.util.CacheMap

CacheMap.Value<V>

Field Summary

protected Loader<K,V>

_loader The loader.

Fields inherited from class org.zkoss.util.CacheMap

EXPUNGE_CONTINUE, EXPUNGE_NO, EXPUNGE_STOP, EXPUNGE_YES

Fields inherited from interface org.zkoss.util.Cache

DEFAULT_LIFETIME, DEFAULT_MAX_SIZE

Constructor Summary

ResourceCache(Loader<K,V> loader)
Constructor.

ResourceCache(Loader<K,V> loader, int initsz)
Constructor.

Method Summary

void	clear() It is OK to clear up all cached resources if you don't want to cache it.
V	get(Object src) Returns the resource, or null if not found.
int	getCheckPeriod() Returns how often to check (unit=milliseconds).
Loader<K,V>	getLoader() Returns the loader.
Object	put(Object src, Object val) Don't use it.
Object	remove(Object src) It is OK to remove the resource if you don't want to cache it.
ResourceCache	setCheckPeriod(int checkPeriod) Sets how often to check (unit=milliseconds).

Methods inherited from class org.zkoss.util.CacheMap

canExpunge, clone, containsKey, containsKeyWithoutExpunge, containsValue, entrySet, equals, expunge, getLifetime, getMaxSize, getWithoutExpunge, hashCode, isEmpty, isEmptyWithoutExpunge, keySet, onExpunge, putAll, setLifetime, setMaxSize, shallExpunge, size, sizeWithoutExpunge, toString, values

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

_loader

protected final Loader<K,V> _loader

The loader.

Constructor Detail

ResourceCache

public ResourceCache(Loader<K,V> loader)

Constructor.

Parameters:

loader - the loader to load resource

ResourceCache

public ResourceCache(Loader<K,V> loader,
                     int initsz)

Constructor.

Parameters:

loader - the loader to load resource

initsz - the initial size of the map

Method Detail

getLoader

public Loader<K,V> getLoader()

Returns the loader.

getCheckPeriod

public int getCheckPeriod()

Returns how often to check (unit=milliseconds).

Default: 5000

setCheckPeriod

public ResourceCache setCheckPeriod(int checkPeriod)

Sets how often to check (unit=milliseconds).

Returns:

this object

get

public V get(Object src)

Returns the resource, or null if not found.

Specified by:

get in interface Map<Object,Object>

Specified by:

get in interface Cache<Object,Object>

Overrides:

get in class CacheMap<Object,Object>

put

public Object put(Object src,
                  Object val)

Don't use it.

Specified by:

put in interface Map<Object,Object>

Specified by:

put in interface Cache<Object,Object>

Overrides:

put in class CacheMap<Object,Object>

Returns:

the previous value of the same, or null if no such value

Throws:

UnsupportedOperationException - if called

remove

public Object remove(Object src)

It is OK to remove the resource if you don't want to cache it. It is thread safe.

Specified by:

remove in interface Map<Object,Object>

Specified by:

remove in interface Cache<Object,Object>

Overrides:

remove in class CacheMap<Object,Object>

Returns:

the object if found.

clear

public void clear()

It is OK to clear up all cached resources if you don't want to cache it. It is thread safe.

Specified by:

clear in interface Map<Object,Object>

Specified by:

clear in interface Cache<Object,Object>

Overrides:

clear in class CacheMap<Object,Object>