Cache

java.lang.Object
- com.sodius.mdw.server.utils.Cache<K,V>

Type Parameters:

K - the type of keys.

V - the type of values.

All Implemented Interfaces:

Disposable
```
public class Cache<K,V>
extends Object
implements Disposable
```
Provides a cache facility that allows to store key/pair values with an expiration option. When a pair is expired, i.e. the number of second the pair has not been requested is greater than the desired expiration setting, the pair is automatically removed from the cache.
Clients may subclass this class.

Field Summary

Fields
Modifier and Type Field and Description

static long NO_EXPIRATION
A negative integer to be used as expiration setting when no expiration is desired, i.e.

Fields
Modifier and Type	Field and Description
`static long`	`NO_EXPIRATION` A negative integer to be used as expiration setting when no expiration is desired, i.e.

Constructor Summary

Constructors
Constructor and Description

Cache(long expiration)
Instantiates a cache that uses the specified default expiration setting.

Constructors
Constructor and Description
`Cache(long expiration)` Instantiates a cache that uses the specified default expiration setting.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clean()` Removes the cache entries that are expired.
`boolean`	`containsKey(K key)` Determines whether the cache contains an entry matching the specified key.
`void`	`dispose()` Disposes the cache, which also disposes each cached value that implements `Disposable`.
`V`	`get(K key)` Returns the value assigned to the specified key in the cache.
`long`	`getExpiration()` Returns the default cache expiration, i.e.
`long`	`getExpiration(K key)` Returns the cache expiration for the specified key, i.e.
`void`	`put(K key, V object)` Changes the value assigned to the specified key in the cache.
`void`	`remove(K key)` Removes the cache entry matching the specified key.
`void`	`removeExpiration(K key)` Remove the specific expiration assigned to the cache entry identified by the specified key.
`void`	`setExpiration(K key, long expiration)` Changes the cache expiration for the specified key, i.e.
`void`	`setExpiration(long expiration)` Changes the default cache expiration, i.e.
`Map<K,V>`	`toMap()` Copies the content of this cache into a `Map` instance.

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - NO_EXPIRATION
```
public static final long NO_EXPIRATION
```
    A negative integer to be used as expiration setting when no expiration is desired, i.e. no cache entry shall be automatically removed.
    
    See Also:
    
    setExpiration(long), Constant Field Values
- Constructor Detail
  - Cache
```
public Cache(long expiration)
```
    Instantiates a cache that uses the specified default expiration setting.
    
    Parameters:
    
    expiration - the number of milliseconds after which a cache entry is considered expired. A negative number disables the expiration monitoring.
- Method Detail
  - getExpiration
```
public long getExpiration()
```
    Returns the default cache expiration, i.e. the number of milliseconds after which a cache entry is considered expired.
    
    Returns:
    
    the default number of milliseconds after which a cache entry is considered expired.
    
    See Also:
    
    getExpiration(Object)
  - setExpiration
```
public void setExpiration(long expiration)
```
    Changes the default cache expiration, i.e. the default number of milliseconds after which a cache entry is considered expired.
    
    Parameters:
    
    expiration - the new number of milliseconds after which a cache entry is considered expired. A negative number disables the expiration monitoring.
    
    See Also:
    
    setExpiration(Object, long)
  - getExpiration
```
public long getExpiration(K key)
```
    Returns the cache expiration for the specified key, i.e. the number of milliseconds after which this cache entry is considered expired.
    
    Parameters:
    
    key - the key identifying the cache entry for which the expiration is to determine.
    
    Returns:
    
    the number of milliseconds after which the cache entry is considered expired.
    
    See Also:
    
    getExpiration()
  - setExpiration
```
public void setExpiration(K key,
                          long expiration)
```
    Changes the cache expiration for the specified key, i.e. the number of milliseconds after which this cache entry is considered expired.
    
    Parameters:
    
    key - the key identifying the cache entry for which the expiration is to change.
    
    expiration - the new number of milliseconds after which this cache entry is considered expired. A negative number disables the expiration monitoring.
    
    See Also:
    
    setExpiration(long)
  - removeExpiration
```
public void removeExpiration(K key)
```
    Remove the specific expiration assigned to the cache entry identified by the specified key. As a result, the default expiration is going to be used for this cache entry.
    
    Parameters:
    
    key - the key identifying the cache entry for which the specific expiration is to remove.
    
    See Also:
    
    getExpiration()
  - containsKey
```
public boolean containsKey(K key)
```
    Determines whether the cache contains an entry matching the specified key.
    
    Parameters:
    
    key - the cache entry to look for.
    
    Returns:
    
    true if the key is found in the cache, false otherwise.
  - get
```
public V get(K key)
```
    Returns the value assigned to the specified key in the cache.
    
    Parameters:
    
    key - the cache entry to look for.
    
    Returns:
    
    the cached value, null if none.
  - put
```
public void put(K key,
                V object)
```
    Changes the value assigned to the specified key in the cache.
    
    Parameters:
    
    key - the cache entry to look for.
    
    object - the value to put in the cache.
  - remove
```
public void remove(K key)
```
    Removes the cache entry matching the specified key.
    
    Parameters:
    
    key - the cache entry to look for.
  - clean
```
public void clean()
```
    Removes the cache entries that are expired. MDWorkbench Server periodically performs a cleanup of all known cache instances, therefore client generally doesn't need to call this method on his own.
    
    See Also:
    
    getExpiration()
  - dispose
```
public void dispose()
```
    Disposes the cache, which also disposes each cached value that implements Disposable.
    
    Specified by:
    
    dispose in interface Disposable
  - toMap
```
public Map<K,V> toMap()
```
    Copies the content of this cache into a Map instance.
    
    Returns:
    
    a non-modifiable Map instance which contains all cache entries.

Class Cache<K,V>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

NO_EXPIRATION

Constructor Detail

Cache

Method Detail

getExpiration

setExpiration

getExpiration

setExpiration

removeExpiration

containsKey

get

put

remove

clean

dispose

toMap