net.itrixlabs.cache.core

Class AbstractFileSystemCache<V>

java.lang.Object

net.itrixlabs.cache.core.AbstractFileSystemCache<V>

All Implemented Interfaces:

Serializable, ApplicationCache<Key,V>, org.springframework.beans.factory.DisposableBean, org.springframework.beans.factory.InitializingBean

Direct Known Subclasses:

SerializableAuthCache, SerializableCsrfCache, SerializableGenericCache, SerializableUserCache

public abstract class AbstractFileSystemCache<V>
extends Object
implements ApplicationCache<Key,V>, Serializable

Extends the ApplicationCache contract providing base for using file system as storage for the cache.

Since:

November 11^th, 2015

Author:

Abhinav Rai

See Also:

ApplicationCache, Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
protected ConcurrentMap<Key,V>	cache
protected Long	ttl
protected TimeUnit	ttlUnit

Constructor Summary

Constructors

Constructor and Description
AbstractFileSystemCache() This constructor should not be used for invoking a cache.
AbstractFileSystemCache(CacheType type) Constructs an AbstractFileSystemCache with the given type of auth token.
AbstractFileSystemCache(CacheType type, String cacheDir, String cacheFile) Constructs an AbstractFileSystemCache with the given type of auth token, the cache storage directory and cache file name.

Method Summary

Modifier and Type	Method and Description
void	afterPropertiesSet()
void	destroy()
void	flush()
protected Key	generate(Object identifier) A native strategy to generate the cache key.
Long	getTtl() Returns the set time-to-live for the entries in cache.
TimeUnit	getTtlUnit() Returns the set time-to-live time unit for the entries in cache.
void	initialize() Initializes the application cache (doesn't create it).
boolean	isPresentInCache(Object key) Checks the application cache on which the method is called for the specified key and returns true if the condition is true, else false.
void	setCacheDir(String cacheDir) Sets the cache directory location to use with the particular type of cache in focus.
void	setCacheFile(String cacheFile) Sets the cache filename to use with the particular type of cache in focus.
void	setTtl(Long ttl, TimeUnit ttlUnit) Sets the time-to-live & the time unit for cache entry time-to-live strategy (applicable to each entry in the cache).

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.itrixlabs.cache.core.ApplicationCache

evictFromCache, getFromCache, putInCache

Field Detail

ttl

protected Long ttl

ttlUnit

protected TimeUnit ttlUnit

cache

protected final ConcurrentMap<Key,V> cache

Constructor Detail

AbstractFileSystemCache

public AbstractFileSystemCache()

This constructor should not be used for invoking a cache. Instead, one should use the variant which takes a CacheType argument at-least.

AbstractFileSystemCache

public AbstractFileSystemCache(CacheType type)

Constructs an AbstractFileSystemCache with the given type of auth token. Sensible defaults will be used for other required parameters unless explicitly set. An application can typically have several instances of auth cache to store different types of auth tokens (for example, a scenario with multiple authentication/authorization providers using different user details services).

Parameters:

type - the cache type to use

AbstractFileSystemCache

public AbstractFileSystemCache(CacheType type,
                               String cacheDir,
                               String cacheFile)

Constructs an AbstractFileSystemCache with the given type of auth token, the cache storage directory and cache file name. Provides better control on caching strategy out of the box. An application can typically have several instances of auth cache to store different types of auth tokens (for example, a scenario with multiple authentication/authorization providers using different user details services).

Parameters:

type - the cache type to use

cacheDir - the cache directory to use

cacheFile - the cache filename to use

Method Detail

initialize

public void initialize()

Description copied from interface: ApplicationCache

Initializes the application cache (doesn't create it). Can make use of a data-store for pre-fetching already stored application data (if required) typically upon container restart.

Each type of application cache is initialized separately in order to maintain sanity and usage simplicity. Thus, please be advised that a cache type must be instantiated & initialized manually before use (manually just means that extra code is required for the same).

Specified by:

initialize in interface ApplicationCache<Key,V>

generate

protected Key generate(Object identifier)

A native strategy to generate the cache key. Uses the key identifier and current time stamp (as creation time) and should be enough for almost everything. However, if you crave to override it, you may!

Parameters:

identifier - the key identifier to set

Returns:

the Key typically an instance of CacheKey for use as key for a cache entry

isPresentInCache

public boolean isPresentInCache(Object key)

Description copied from interface: ApplicationCache

Checks the application cache on which the method is called for the specified key and returns true if the condition is true, else false.

Important: Note that you may use any well known java type as key like Long or String or a custom type as long as it abides by the contract defined by the Key interface, i.e., the key should be uniquely identifiable using its value and not the Key instance as whole. In short, you must override the Object.equals(Object) and Object.hashCode() methods of that particular key type to make sure your identifier can be uniquely distinguished from with-in the cache.

Specified by:

isPresentInCache in interface ApplicationCache<Key,V>

Parameters:

key - the key to be tested for presence in the cache

Returns:

true if the key exists, else false (an exception must never be thrown)

flush

public void flush()

Specified by:

flush in interface ApplicationCache<Key,V>

afterPropertiesSet

public void afterPropertiesSet()
                        throws Exception

Specified by:

afterPropertiesSet in interface org.springframework.beans.factory.InitializingBean

Throws:

Exception

destroy

public void destroy()
             throws Exception

Specified by:

destroy in interface org.springframework.beans.factory.DisposableBean

Throws:

Exception

setTtl

public void setTtl(Long ttl,
                   TimeUnit ttlUnit)

Sets the time-to-live & the time unit for cache entry time-to-live strategy (applicable to each entry in the cache).

Parameters:

ttl - the ttl to set

ttlUnit - the ttl time unit to set

setCacheDir

public void setCacheDir(String cacheDir)

Sets the cache directory location to use with the particular type of cache in focus.

Parameters:

cacheDir - the cache directory location to use

setCacheFile

public void setCacheFile(String cacheFile)

Sets the cache filename to use with the particular type of cache in focus.

Parameters:

cacheFile - the cache filename to use

getTtl

public Long getTtl()

Returns the set time-to-live for the entries in cache.

Returns:

the ttl for entries in cache

getTtlUnit

public TimeUnit getTtlUnit()

Returns the set time-to-live time unit for the entries in cache.

Returns:

the ttl time unit for entries in cache