software.amazon.jdbc.util

Class ExpiringCache<K,V>

java.lang.Object

software.amazon.jdbc.util.ExpiringCache<K,V>

Type Parameters:

K - The type of the key to store

V - The type of the value to store

All Implemented Interfaces:

java.util.Map<K,V>

public class ExpiringCache<K,V>
extends java.lang.Object
implements java.util.Map<K,V>

Expiring Cache class. This cache uses a LinkedHashMap to store values with a specific time they were stored. Items that exceed the expired time will be removed when attempting to retrieve them.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static interface	ExpiringCache.OnEvictRunnable<V>

Nested classes/interfaces inherited from interface java.util.Map

java.util.Map.Entry<K,V>

Constructor Summary

Constructors

Constructor and Description
ExpiringCache(long expireTimeMs) Expiring cache constructor.
ExpiringCache(long expireTimeMs, @Nullable ExpiringCache.OnEvictRunnable<V> onEvictRunnable) Expiring cache constructor.

Method Summary

Modifier and Type	Method and Description
void	clear() Clears all mapping from the cache.
boolean	containsKey(java.lang.Object key) Checks if the cache contains a specific key.
boolean	containsValue(java.lang.Object value) Checks if the cache contains a specific value.
java.util.Set<java.util.Map.Entry<K,V>>	entrySet() Returns a Set view of the keys.
V	get(java.lang.Object key) Retrieves the value from a key.
long	getExpireTime() Accessor method for expireTimeMs.
java.util.concurrent.locks.ReentrantLock	getLock()
boolean	isEmpty() Checks whether it is empty.
java.util.Set<K>	keySet() Returns a Set view of the keys.
V	put(K key, V value) Associates a specified value with a specified key in this map.
void	putAll(java.util.Map<? extends K,? extends V> m) Copies the content from one map to the current map.
V	remove(java.lang.Object key) Removes the mapping for a key if it's present.
void	setExpireTime(long expireTimeMs) Mutator method for expireTimeMs.
void	setOnEvictRunnable(ExpiringCache.OnEvictRunnable<V> onEvictRunnable)
int	size() Retrieves the number of items stored.
java.util.Collection<V>	values() Returns a Collection view of the keys.

Methods inherited from class java.lang.Object

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

Methods inherited from interface java.util.Map

compute, computeIfAbsent, computeIfPresent, equals, forEach, getOrDefault, hashCode, merge, putIfAbsent, remove, replace, replace, replaceAll

Constructor Detail

ExpiringCache

public ExpiringCache(long expireTimeMs)

Expiring cache constructor.

Parameters:

expireTimeMs - The expired time in Ms

ExpiringCache

public ExpiringCache(long expireTimeMs,
                     @Nullable ExpiringCache.OnEvictRunnable<V> onEvictRunnable)

Expiring cache constructor.

Parameters:

expireTimeMs - The expired time in Ms

onEvictRunnable - A function that will be called on each evicted cache entry

Method Detail

setExpireTime

public void setExpireTime(long expireTimeMs)

Mutator method for expireTimeMs. Sets the expired time for the cache.

Parameters:

expireTimeMs - The expired time in Ms

getExpireTime

public long getExpireTime()

Accessor method for expireTimeMs.

Returns:

Returns the time it takes for the cache to be "expired"

size

public int size()

Retrieves the number of items stored.

Specified by:

size in interface java.util.Map<K,V>

Returns:

The size of items stored

isEmpty

public boolean isEmpty()

Checks whether it is empty.

Specified by:

isEmpty in interface java.util.Map<K,V>

Returns:

True if it's empty

containsKey

public boolean containsKey(java.lang.Object key)

Checks if the cache contains a specific key.

Specified by:

containsKey in interface java.util.Map<K,V>

Parameters:

key - The key to search for

Returns:

True if the cache contains the key

containsValue

public boolean containsValue(java.lang.Object value)

Checks if the cache contains a specific value.

Specified by:

containsValue in interface java.util.Map<K,V>

Parameters:

value - The value to search for

Returns:

True if the cache contains that value

get

public V get(java.lang.Object key)

Retrieves the value from a key.

Specified by:

get in interface java.util.Map<K,V>

Parameters:

key - The key in the key-value pair

Returns:

The value from the key

put

public V put(K key,
             V value)

Associates a specified value with a specified key in this map.

Specified by:

put in interface java.util.Map<K,V>

Parameters:

key - The key in the key-value pair

value - The value in the key-value pair

Returns:

The previously associated value of the key. If there isn't any then it would return null

remove

public V remove(java.lang.Object key)

Removes the mapping for a key if it's present.

Specified by:

remove in interface java.util.Map<K,V>

Parameters:

key - The key in the map

Returns:

The value associated with the key, or null if there were no mappings for the key.

putAll

public void putAll(java.util.Map<? extends K,? extends V> m)

Copies the content from one map to the current map.

Specified by:

putAll in interface java.util.Map<K,V>

Parameters:

m - The map to copy from

clear

public void clear()

Clears all mapping from the cache.

Specified by:

clear in interface java.util.Map<K,V>

keySet

public java.util.Set<K> keySet()

Returns a Set view of the keys.

Specified by:

keySet in interface java.util.Map<K,V>

Returns:

A set view of the keys in the cache

values

public java.util.Collection<V> values()

Returns a Collection view of the keys.

Specified by:

values in interface java.util.Map<K,V>

Returns:

A collection view of the keys in the cache

entrySet

public java.util.Set<java.util.Map.Entry<K,V>> entrySet()

Returns a Set view of the keys.

Specified by:

entrySet in interface java.util.Map<K,V>

Returns:

A set view of the mappings in the cache

setOnEvictRunnable

public void setOnEvictRunnable(ExpiringCache.OnEvictRunnable<V> onEvictRunnable)

getLock

public java.util.concurrent.locks.ReentrantLock getLock()