org.omnifaces.component.output.cache

Interface Cache

All Superinterfaces:

Serializable

All Known Implementing Classes:

DefaultCache, TimeToLiveCache

public interface Cache
extends Serializable

Interface that abstracts a simple get and put operation for a concrete cache implementation.

Note that this takes Strings for both key and value since it's not intended as a general cache solution, but is something specific for the Cache component which caches rendered output.

Since:

1.1

Author:

Arjan Tijms

Method Summary

Methods

Modifier and Type	Method and Description
String	get(String key) Gets a value from the cache
Object	getAttribute(String key, String name) Gets a named attribute from the cache entry identified by the key parameter.
void	put(String key, String value) Stores a value in the cache
void	put(String key, String value, int timeToLive) Stores a value in the cache
void	putAttribute(String key, String name, Object value, int timeToLive) Stores a named attribute in the cache entry identified by the key parameter.
void	remove(String key) Removes a value from the cache

Method Detail

get

String get(String key)

Gets a value from the cache

Parameters:

key - the key under which a value was previously stored

Returns:

The previously stored value, or null if no such value exists

put

void put(String key,
       String value)

Stores a value in the cache

Parameters:

key - the key under which a value is to be stored

value - the value that is to be stored

put

void put(String key,
       String value,
       int timeToLive)

Stores a value in the cache

Parameters:

key - the key under which a value is to be stored

value - the value that is to be stored

timeToLive - the amount of time in seconds for which the cached value is valid from the time it's being added to the cache. It's provider specific whether the cache implementation will actually remove (evict) the entry after this time has elapsed or will only perform a check upon accessing the cache entry. Whatever method the implementation chooses; after this time is elapsed a call to get(String) should return null.

getAttribute

Object getAttribute(String key,
                  String name)

Gets a named attribute from the cache entry identified by the key parameter.

This in effect implements a 2-level multi-map, which the single main value stored in the first level, and the optional attributes stored in the second level.

Parameters:

key - key that identifies the first level cache entry

name - name of the attribute in the second level

Returns:

the value associated with the {key, name} hierarchy.

Since:

1.2

putAttribute

void putAttribute(String key,
                String name,
                Object value,
                int timeToLive)

Stores a named attribute in the cache entry identified by the key parameter.

Parameters:

key - key that identifies the first level cache entry

name - name of the attribute in the second level

value - value associated with the {key, name} hierarchy.

timeToLive - the amount of time in seconds for which the cached value is valid. Only used when there's no first level entry yet. See putAttribute(String, String, Object, int)

Since:

1.2

remove

void remove(String key)

Removes a value from the cache

Parameters:

key - the key under which a value is to be stored