SoftValueHashMap (Geotools modules 21.0 API)

Object
- AbstractMap<K,V>
- - SoftValueHashMap<K,V>

Type Parameters:

K - The type of keys in the map.

V - The type of values in the map.

All Implemented Interfaces:

Map<K,V>
```
public class SoftValueHashMap<K,V>
extends AbstractMap<K,V>
```
A hash map implementation that uses soft references, leaving memory when an entry is not used anymore and memory is low.
This map implementation actually maintains some of the first entries as hard references. Only oldest entries are retained by soft references, in order to avoid too aggressive garbage collection. The amount of entries to retain by hard reference is specified at construction time.
This map is thread-safe. It accepts the null key; it does not accept the null value. Usage of value, key or entry collections are supported. The iterator on the ConcurrentHashMap is weakly consistent.

Since:

2.3

Author:

Simone Giannecchini, Martin Desruisseaux, Ugo Moschini

Nested Class Summary

Nested Classes
Modifier and Type	Class and Description
`static interface`	`SoftValueHashMap.ValueCleaner` A delegate that can be used to perform clean up operation, such as resource closing, before the values cached in soft part of the cache gets disposed of

Nested classes/interfaces inherited from class AbstractMap
AbstractMap.SimpleEntry<K,V>, AbstractMap.SimpleImmutableEntry<K,V>

Nested classes/interfaces inherited from interface Map
Map.Entry<K,V>

Field Summary

Fields
Modifier and Type Field and Description

protected SoftValueHashMap.ValueCleaner cleaner
The eventual cleaner

Fields
Modifier and Type	Field and Description
`protected SoftValueHashMap.ValueCleaner`	`cleaner` The eventual cleaner

Constructor Summary

Constructors
Constructor and Description
`SoftValueHashMap()` Creates a map with the default hard references count.
`SoftValueHashMap(int hardReferencesCount)` Creates a map with the specified hard references count.
`SoftValueHashMap(int hardReferencesCount, SoftValueHashMap.ValueCleaner cleaner)` Creates a map with the specified hard references count.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`clear()` Removes all mappings from this map.
`boolean`	`containsKey(Object key)` Returns `true` if this map contains a mapping for the specified key.
`boolean`	`containsValue(Object value)` Returns `true` if this map maps one or more keys to this value.
`Set<Map.Entry<K,V>>`	`entrySet()` Returns a set view of the mappings contained in this map.
`boolean`	`equals(Object object)` Compares the specified object with this map for equality.
`V`	`get(Object key)` Returns the value to which this map maps the specified key.
`int`	`getHardReferencesCount()` Returns the number of hard references kept in this cache
`int`	`hashCode()` Returns the hash code value for this map.
`V`	`put(K key, V value)` Associates the specified value with the specified key in this map.
`void`	`putAll(Map<? extends K,? extends V> map)` Copies all of the mappings from the specified map to this map.
`V`	`remove(Object key)` Removes the mapping for this key from this map if present.
`int`	`size()` Returns the number of entries in this map.
`String`	`toString()` Returns a string representation of this map.

Methods inherited from class AbstractMap
clone, isEmpty, keySet, values

Methods inherited from class Object
finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface Map
compute, computeIfAbsent, computeIfPresent, forEach, getOrDefault, merge, putIfAbsent, remove, replace, replace, replaceAll

- Field Detail
  - cleaner
```
protected SoftValueHashMap.ValueCleaner cleaner
```
    The eventual cleaner
- Constructor Detail
  - SoftValueHashMap
```
public SoftValueHashMap()
```
    Creates a map with the default hard references count.
  - SoftValueHashMap
```
public SoftValueHashMap(int hardReferencesCount)
```
    Creates a map with the specified hard references count.
    
    Parameters:
    
    hardReferencesCount - The maximal number of hard references to keep.
  - SoftValueHashMap
```
public SoftValueHashMap(int hardReferencesCount,
                        SoftValueHashMap.ValueCleaner cleaner)
```
    Creates a map with the specified hard references count.
    
    Parameters:
    
    hardReferencesCount - The maximal number of hard references to keep.
- Method Detail
  - getHardReferencesCount
```
public int getHardReferencesCount()
```
    Returns the number of hard references kept in this cache
    
    Returns:
  - size
```
public int size()
```
    Returns the number of entries in this map.
    
    Specified by:
    
    size in interface Map<K,V>
    
    Overrides:
    
    size in class AbstractMap<K,V>
  - containsKey
```
public boolean containsKey(Object key)
```
    Returns true if this map contains a mapping for the specified key.
    
    Specified by:
    
    containsKey in interface Map<K,V>
    
    Overrides:
    
    containsKey in class AbstractMap<K,V>
  - containsValue
```
public boolean containsValue(Object value)
```
    Returns true if this map maps one or more keys to this value.
    
    Specified by:
    
    containsValue in interface Map<K,V>
    
    Overrides:
    
    containsValue in class AbstractMap<K,V>
  - get
```
public V get(Object key)
```
    Returns the value to which this map maps the specified key. Returns null if the map contains no mapping for this key, or the value has been garbage collected.
    
    Specified by:
    
    get in interface Map<K,V>
    
    Overrides:
    
    get in class AbstractMap<K,V>
    
    Parameters:
    
    key - key whose associated value is to be returned.
    
    Returns:
    
    the value to which this map maps the specified key, or null if none.
  - put
```
public V put(K key,
             V value)
```
    Associates the specified value with the specified key in this map.
    
    Specified by:
    
    put in interface Map<K,V>
    
    Overrides:
    
    put in class AbstractMap<K,V>
    
    Parameters:
    
    key - Key with which the specified value is to be associated.
    
    value - Value to be associated with the specified key. The value can't be null.
    
    Returns:
    
    Previous value associated with specified key, or null if there was no mapping for key.
  - putAll
```
public void putAll(Map<? extends K,? extends V> map)
```
    Copies all of the mappings from the specified map to this map.
    
    Specified by:
    
    putAll in interface Map<K,V>
    
    Overrides:
    
    putAll in class AbstractMap<K,V>
    
    Parameters:
    
    map - Mappings to be stored in this map.
  - remove
```
public V remove(Object key)
```
    Removes the mapping for this key from this map if present.
    
    Specified by:
    
    remove in interface Map<K,V>
    
    Overrides:
    
    remove in class AbstractMap<K,V>
    
    Parameters:
    
    key - Key whose mapping is to be removed from the map.
    
    Returns:
    
    previous value associated with specified key, or null if there was no entry for key.
  - clear
```
public void clear()
```
    Removes all mappings from this map.
    
    Specified by:
    
    clear in interface Map<K,V>
    
    Overrides:
    
    clear in class AbstractMap<K,V>
  - entrySet
```
public Set<Map.Entry<K,V>> entrySet()
```
    Returns a set view of the mappings contained in this map.
    
    Specified by:
    
    entrySet in interface Map<K,V>
    
    Specified by:
    
    entrySet in class AbstractMap<K,V>
  - equals
```
public boolean equals(Object object)
```
    Compares the specified object with this map for equality.
    
    Specified by:
    
    equals in interface Map<K,V>
    
    Overrides:
    
    equals in class AbstractMap<K,V>
    
    Parameters:
    
    object - The object to compare with this map for equality.
  - hashCode
```
public int hashCode()
```
    Returns the hash code value for this map.
    
    Specified by:
    
    hashCode in interface Map<K,V>
    
    Overrides:
    
    hashCode in class AbstractMap<K,V>
  - toString
```
public String toString()
```
    Returns a string representation of this map.
    
    Overrides:
    
    toString in class AbstractMap<K,V>

Class SoftValueHashMap<K,V>

Nested Class Summary

Nested classes/interfaces inherited from class AbstractMap

Nested classes/interfaces inherited from interface Map

Field Summary

Constructor Summary

Method Summary

Methods inherited from class AbstractMap

Methods inherited from class Object

Methods inherited from interface Map

Field Detail

cleaner

Constructor Detail

SoftValueHashMap

SoftValueHashMap

SoftValueHashMap

Method Detail

getHardReferencesCount

size

containsKey

containsValue

get

put

putAll

remove

clear

entrySet

equals

hashCode

toString