net.dontdrinkandroot.cache.impl.memory

Class NoopCache<K,V>

java.lang.Object

net.dontdrinkandroot.cache.impl.memory.NoopCache<K,V>

All Implemented Interfaces:

Cache<K,V>, CustomTtlCache<K,V>

public class NoopCache<K,V>
extends Object
implements CustomTtlCache<K,V>

A serializable cache that does not actually perform any caching operation.

Author:

Philip W. Sorst

Field Summary

Fields inherited from interface net.dontdrinkandroot.cache.Cache

UNLIMITED_IDLE_TIME

Constructor Summary

Constructors

Constructor and Description
NoopCache(String name)

Method Summary

Methods

Modifier and Type	Method and Description
void	cleanUp() Removes expired and stale entries.
void	delete(K key) Manually remove an entry from the cache.
void	expunge() Cleanup the cache.
<T extends V> T	get(K key) Retrieve an entry from the cache if it is available.
long	getDefaultMaxIdleTime() Get the default max idle time for cache entries.
long	getDefaultTtl() Retrieve the default time to live for cache entries.
MetaData	getMetaData(K key) Retrieve the MetaData of a cached entry if it is available.
String	getName() Get the name of this cache.
CacheStatistics	getStatistics() Get statistics of the cache like hitrate, or size.
<T extends V> T	getWithErrors(K key) Retrieve an entry from the cache if it is available.
<T extends V> T	put(K key, T data) Store an entry in the cache with the default time to live.
<T extends V> T	put(K key, T data, long timeToLive) Store an entry in the cache with a specific time to live.
<T extends V> T	put(K key, T data, long timeToLive, long maxIdleTime) Store an entry in the cache with a specific time to live and max idle time.
<T extends V> T	putWithErrors(K key, T data) Store an entry in the cache with the default time to live.
<T extends V> T	putWithErrors(K key, T data, long timeToLive) Store an entry in the cache with a specific time to live.
<T extends V> T	putWithErrors(K key, T data, long timeToLive, long maxIdleTime) Store an entry in the cache with a specific time to live and max idle time.
void	setDefaultTtl(long defaultTTL) Sets the default time to live for cache entries.
void	setName(String name)

Methods inherited from class java.lang.Object

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

Constructor Detail

NoopCache

public NoopCache(String name)

Method Detail

putWithErrors

public <T extends V> T putWithErrors(K key,
                            T data)
                          throws CacheException

Description copied from interface: Cache

Store an entry in the cache with the default time to live.

Specified by:

putWithErrors in interface Cache<K,V>

Parameters:

key - A unique identifier.

data - The data to store. Make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned data instead.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always (at least) a copy.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

getWithErrors

public <T extends V> T getWithErrors(K key)
                          throws CacheException

Description copied from interface: Cache

Retrieve an entry from the cache if it is available.

Specified by:

getWithErrors in interface Cache<K,V>

Parameters:

key - The unique key under which the entry was stored.

Returns:

The cache entry if it is valid and not expired, null otherwise.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

getMetaData

public MetaData getMetaData(K key)
                     throws CacheException

Description copied from interface: Cache

Retrieve the MetaData of a cached entry if it is available.

Specified by:

getMetaData in interface Cache<K,V>

Parameters:

key - The key under which the entry was stored.

Returns:

The MetaData of the entry if found, null otherwise.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

setDefaultTtl

public void setDefaultTtl(long defaultTTL)

Description copied from interface: Cache

Sets the default time to live for cache entries.

Specified by:

setDefaultTtl in interface Cache<K,V>

Parameters:

defaultTTL - The default time to live for a cache entry in milliseconds.

getDefaultTtl

public long getDefaultTtl()

Description copied from interface: Cache

Retrieve the default time to live for cache entries.

Specified by:

getDefaultTtl in interface Cache<K,V>

Returns:

The default time to live for a cache entry in milliseconds.

delete

public void delete(K key)
            throws CacheException

Description copied from interface: Cache

Manually remove an entry from the cache.

Specified by:

delete in interface Cache<K,V>

Parameters:

key - The key under which the entry was stored.

Throws:

CacheException - Thrown on any errors encountered, supposed to include the stacktrace (if any).

expunge

public void expunge()

Description copied from interface: Cache

Cleanup the cache. Usually this means that expired entries are deleted but this can also incorporate optimization functions etc. depending on the implementation.

Specified by:

expunge in interface Cache<K,V>

setName

public void setName(String name)

getName

public String getName()

Description copied from interface: Cache

Get the name of this cache.

Specified by:

getName in interface Cache<K,V>

Returns:

The name of this cache.

putWithErrors

public <T extends V> T putWithErrors(K key,
                            T data,
                            long timeToLive)
                          throws CacheException

Description copied from interface: CustomTtlCache

Store an entry in the cache with a specific time to live.

Specified by:

putWithErrors in interface CustomTtlCache<K,V>

data - The data to store, make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned entry instead.

timeToLive - The time (in milliseconds) after which the entry expires.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always a copy.

Throws:

CacheException - Thrown if the storage fails.

getStatistics

public CacheStatistics getStatistics()

Description copied from interface: Cache

Get statistics of the cache like hitrate, or size.

Specified by:

getStatistics in interface Cache<K,V>

Returns:

Statistics of the cache.

getDefaultMaxIdleTime

public long getDefaultMaxIdleTime()

Description copied from interface: Cache

Get the default max idle time for cache entries.

Specified by:

getDefaultMaxIdleTime in interface Cache<K,V>

Returns:

The default max idle time for cache entries in milliseconds.

putWithErrors

public <T extends V> T putWithErrors(K key,
                            T data,
                            long timeToLive,
                            long maxIdleTime)
                          throws CacheException

Description copied from interface: CustomTtlCache

Store an entry in the cache with a specific time to live and max idle time.

Specified by:

putWithErrors in interface CustomTtlCache<K,V>

data - The data to store, make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned entry instead.

timeToLive - The time (in milliseconds) after which the entry expires.

maxIdleTime - The time (in milliseconds) that an entry may idle (not being accessed) before being expunged.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always a copy.

Throws:

CacheException - Thrown if the storage fails.

put

public <T extends V> T put(K key,
                  T data)

Description copied from interface: Cache

Store an entry in the cache with the default time to live. Any errors are swallowed, use Cache.putWithErrors(Object, Object) if you want to handle them.

Specified by:

put in interface Cache<K,V>

Parameters:

key - A unique identifier.

data - The data to store. Make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned data instead.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always (at least) a copy.

get

public <T extends V> T get(K key)

Description copied from interface: Cache

Retrieve an entry from the cache if it is available. Any errors are swallowed, use Cache.getWithErrors(Object) if you want to handle them.

Specified by:

get in interface Cache<K,V>

Parameters:

key - The unique key under which the entry was stored.

Returns:

The cache entry if it is valid and not expired, null otherwise.

put

public <T extends V> T put(K key,
                  T data,
                  long timeToLive)

Description copied from interface: CustomTtlCache

Store an entry in the cache with a specific time to live. Any errors are swallowed, use CustomTtlCache.put(Object, Object, long) if you want to handle them.

Specified by:

put in interface CustomTtlCache<K,V>

data - The data to store, make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned entry instead.

timeToLive - The time (in milliseconds) after which the entry expires.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always a copy.

put

public <T extends V> T put(K key,
                  T data,
                  long timeToLive,
                  long maxIdleTime)

Description copied from interface: CustomTtlCache

Store an entry in the cache with a specific time to live and max idle time. Any errors are swallowed, use CustomTtlCache.putWithErrors(Object, Object, long) if you want to handle them.

Specified by:

put in interface CustomTtlCache<K,V>

data - The data to store, make sure that you don't alter the data after it has been put to cache as (depending on the implementation) this might lead to altering the entry in the cache. Use the returned entry instead.

timeToLive - The time (in milliseconds) after which the entry expires.

maxIdleTime - The time (in milliseconds) that an entry may idle (not being accessed) before being expunged.

Returns:

The entry that has been stored in the cache. It is save to alter this as implementations as implementations make sure that this is always a copy.

cleanUp

public void cleanUp()
             throws CacheException

Description copied from interface: Cache

Removes expired and stale entries.

Specified by:

cleanUp in interface Cache<K,V>

Throws:

CacheException - Thrown if the cleanup failed.