Package com.alachisoft.ncache.client

Class CacheItem

java.lang.Object

com.alachisoft.ncache.client.CacheItem

All Implemented Interfaces:

java.lang.Cloneable

public class CacheItem
extends java.lang.Object
implements java.lang.Cloneable

NCache uses a "key" and "value" structure for storing objects in cache. When an object is added in cache it is stored as value and metadata against the specified key. This combination of value and metadata is defined as CacheItem in NCache. The value of the objects stored in the cache can range from being simple string types to complex objects. CacheItem class in NCache has properties that enable you to set metadata for the item to be added in cache in an organized way. In scenarios where multiple attributes have to be set while adding an item in cache using CacheItem is preferred.Using CacheItem class object removes the problem of using multiple API overloads on adding/updating data in cache.You can easily use the basic API overload and add/update data easily using CacheItem.

Constructor Summary

Constructors

Constructor	Description
CacheItem()	Initialize new instance of cache item.
CacheItem(java.lang.Object value)	Initialize new instance of cache item.

Method Summary

Modifier and Type	Method	Description
void	addCacheDataNotificationListener(CacheDataModificationListener listener, java.util.EnumSet<EventType> eventType, EventDataFilter datafilter)	You can use this to notify applications when their objects are updated or removed in the cache.
java.lang.Object	clone()	Creates a shallow copy of CacheItem
CacheItemPriority	getCacheItemPriority()	Gets the relative priority for cache item which is kept under consideration whenever cache starts to free up space and evicts items.
CacheItemVersion	getCacheItemVersion()	Gets the version associated with the cache item.Version is basically a numeric value that is used to represent the version of the cached item which changes with every update to an item.
java.util.Date	getCreationTime()	Gets the time when the item was added in cache for the first time.
CacheDependency	getDependency()	Gets the Cache Dependency instance that contains all dependencies associated with cache item.
Expiration	getExpiration()	Gets the expiration mechanism for cache item.
java.lang.String	getGroup()	Gets the group associated with the cache item.
java.util.Date	getLastModifiedTime()	Gets the lastModifiedTime of the cache item.CacheItem stores the last modified time of the cache item.
NamedTagsDictionary	getNamedTags()	Gets the NamedTags information associated with the cache item, it can be queried on the basis of NamedTags provided.
ResyncOptions	getResyncOptions()	Gets the ResyncOptions specific to the cache item.
CacheSyncDependency	getSyncDependency()	Synchronizes two separate caches so that an item updated or removed from one cache can have the same effect on the synchronized cache.
java.util.List<Tag>	getTags()	Gets the tags information associated with the cache item, it can be queried on the basis of Tags provided.
<T> T	getValue(java.lang.Class<?> cls)	Returns the value stored in the cache item.
void	removeCacheDataNotificationListener(CacheDataModificationListener listener, java.util.EnumSet<EventType> eventEnumSet)	Unregisters the user from cache data modification notifications.
void	setCacheItemPriority(CacheItemPriority value)	Sets the relative priority for cache item which is kept under consideration whenever cache starts to free up space and evicts items.
void	setCacheItemVersion(CacheItemVersion value)	Sets the version associated with the cache item.Version is basically a numeric value that is used to represent the version of the cached item which changes with every update to an item.
void	setDependency(CacheDependency value)	Sets the Cache Dependency instance that contains all dependencies associated with cache item.
void	setExpiration(Expiration value)	Sets the expiration mechanism for cache item.
void	setGroup(java.lang.String value)	Sets the group associated with the cache item.
void	setNamedTags(NamedTagsDictionary value)	Sets the NamedTags information associated with the cache item, it can be queried on the basis of NamedTags provided.
void	setResyncOptions(ResyncOptions value)	Sets the ResyncOptions specific to the cache item.
void	setSyncDependency(CacheSyncDependency value)	Synchronizes two separate caches so that an item updated or removed from one cache can have the same effect on the synchronized cache.
void	setTags(java.util.List<Tag> value)	Sets the tags information associated with the cache item, it can be queried on the basis of Tags provided.
void	setValue(java.lang.Object value)	Sets the value of the cache item.

Methods inherited from class java.lang.Object

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

Constructor Detail

CacheItem

public CacheItem()

Initialize new instance of cache item.

CacheItem

public CacheItem(java.lang.Object value)

Initialize new instance of cache item.

Parameters:

value - Actual object to be stored in cache.

Method Detail

getExpiration

public final Expiration getExpiration()

Gets the expiration mechanism for cache item.

Returns:

Expiration instance that contains info about cache item expiration mechanism.

setExpiration

public final void setExpiration(Expiration value)

Sets the expiration mechanism for cache item.

Parameters:

value - Expiration object that specifies the expiration mechanism for cache item.

getCacheItemPriority

public final CacheItemPriority getCacheItemPriority()

Gets the relative priority for cache item which is kept under consideration whenever cache starts to free up space and evicts items.

Returns:

CacheItemPriority associated with cache item.

setCacheItemPriority

public final void setCacheItemPriority(CacheItemPriority value)

Sets the relative priority for cache item which is kept under consideration whenever cache starts to free up space and evicts items.

Parameters:

value - CacheItemPriority to be associated with cache item.

getCacheItemVersion

public final CacheItemVersion getCacheItemVersion()

Gets the version associated with the cache item.Version is basically a numeric value that is used to represent the version of the cached item which changes with every update to an item.

Returns:

The version associated with the cache item.

setCacheItemVersion

public final void setCacheItemVersion(CacheItemVersion value)

Sets the version associated with the cache item.Version is basically a numeric value that is used to represent the version of the cached item which changes with every update to an item.

Parameters:

value - The version to be associated with the cache item

getCreationTime

public final java.util.Date getCreationTime()

Gets the time when the item was added in cache for the first time.

Returns:

The date of creation of the cache item.

getLastModifiedTime

public final java.util.Date getLastModifiedTime()

Gets the lastModifiedTime of the cache item.CacheItem stores the last modified time of the cache item. If an item is updated in cache its last modified time is updated as well. Last modified time is checked when Least Recently Used based eviction is triggered.

Returns:

The last modification time of the cache item.

getTags

public final java.util.List<Tag> getTags()

Gets the tags information associated with the cache item, it can be queried on the basis of Tags provided.

Returns:

List of Tags associated with cache item.

setTags

public final void setTags(java.util.List<Tag> value)

Sets the tags information associated with the cache item, it can be queried on the basis of Tags provided.

Parameters:

value - List of Tags to be associated with cache item.

getNamedTags

public final NamedTagsDictionary getNamedTags()

Gets the NamedTags information associated with the cache item, it can be queried on the basis of NamedTags provided.

Returns:

NamedTags associated with cache item.

setNamedTags

public final void setNamedTags(NamedTagsDictionary value)

Sets the NamedTags information associated with the cache item, it can be queried on the basis of NamedTags provided.

Parameters:

value - NamedTags to be associated with cache item.

getResyncOptions

public final ResyncOptions getResyncOptions()

Gets the ResyncOptions specific to the cache item.

Returns:

ResyncOptions specific to the cache item.

setResyncOptions

public final void setResyncOptions(ResyncOptions value)

Sets the ResyncOptions specific to the cache item.

Parameters:

value - ResyncOptions specific to the cache item.

getGroup

public final java.lang.String getGroup()

Gets the group associated with the cache item. It can be queryed on the basis of Groups.

Returns:

The group associated with cache item.

setGroup

public final void setGroup(java.lang.String value)

Sets the group associated with the cache item. It can be queryed on the basis of Groups.

Parameters:

value - The group to be associated with cache item.

getSyncDependency

public final CacheSyncDependency getSyncDependency()

Synchronizes two separate caches so that an item updated or removed from one cache can have the same effect on the synchronized cache. For cache sync dependency, an item must exist in cache before another item can be added with a dependency on it. This property lets you set Cache sync dependency with a cache item.

Returns:

CacheSyncDependency associated with cache item.

setSyncDependency

public final void setSyncDependency(CacheSyncDependency value)

Synchronizes two separate caches so that an item updated or removed from one cache can have the same effect on the synchronized cache. For cache sync dependency, an item must exist in cache before another item can be added with a dependency on it. This property lets you set Cache sync dependency with a cache item.

Parameters:

value - CacheSyncDependency to be associated with cache item.

getDependency

public final CacheDependency getDependency()

Gets the Cache Dependency instance that contains all dependencies associated with cache item.

Returns:

The Cache Dependency instance associated with cache item.

setDependency

public final void setDependency(CacheDependency value)

Sets the Cache Dependency instance that contains all dependencies associated with cache item.

Parameters:

value - The Cache Dependency instance to be associated with cache item.

addCacheDataNotificationListener

public final void addCacheDataNotificationListener(CacheDataModificationListener listener,
                                                   java.util.EnumSet<EventType> eventType,
                                                   EventDataFilter datafilter)

You can use this to notify applications when their objects are updated or removed in the cache. Listeners can be registered against event type/types for the key the items is inserted to. Listeners are overridden for the same event type/types if called again.

Parameters:

listener - Listener to be raised when an item is updated or removed.

eventType - Event type/types the listener is registered against.

datafilter - Tells whether to receive metadata, data with metadata or none when a notification is triggered.

removeCacheDataNotificationListener

public void removeCacheDataNotificationListener(CacheDataModificationListener listener,
                                                java.util.EnumSet<EventType> eventEnumSet)

Unregisters the user from cache data modification notifications.

Parameters:

listener - The listener that is registered for notifications.

eventEnumSet - Event type/types the listener is unregistered against.

getValue

public final <T> T getValue(java.lang.Class<?> cls)
                     throws OperationFailedException

Returns the value stored in the cache item. This value must be serializable.

Type Parameters:

T - Specifies the type of value obtained from the cache item.

Parameters:

cls - Specifies the class of value obtained from the cache item.

Returns:

Value of the cache item with the class defined.

Throws:

OperationFailedException

setValue

public void setValue(java.lang.Object value)

Sets the value of the cache item.

Parameters:

value - object to be stored in cache item.

clone

public final java.lang.Object clone()

Creates a shallow copy of CacheItem

Overrides:

clone in class java.lang.Object

Returns:

The cloned object.