com.vladium.util

类 SoftValueMap

java.lang.Object

com.vladium.util.SoftValueMap

所有已实现的接口:

Map

public final class SoftValueMap
extends Object
implements Map

MT-safety: an instance of this class is not safe for access from multiple concurrent threads [even if access is done by a single thread at a time]. The caller is expected to synchronize externally on an instance [the implementation does not do internal synchronization for the sake of efficiency]. java.util.ConcurrentModificationException is not supported either.

作者:

(C) 2002, Vlad Roubtsov

嵌套类概要

从接口继承的嵌套类/接口 java.util.Map

Map.Entry<K,V>

构造器概要

构造器

构造器和说明
SoftValueMap() Equivalent to SoftValueMap(1, 1).
SoftValueMap(int initialCapacity, float loadFactor, int readClearCheckFrequency, int writeClearCheckFrequency) Constructs a SoftValueMap with specified initial capacity, load factor, and cleared value removal frequencies.
SoftValueMap(int readClearCheckFrequency, int writeClearCheckFrequency) Equivalent to SoftValueMap(11, 0.75F, getClearCheckFrequency, putClearCheckFrequency).

方法概要

限定符和类型	方法和说明
void	clear()
boolean	containsKey(Object key)
boolean	containsValue(Object value)
Set	entrySet()
boolean	equals(Object rhs)
Object	get(Object key) Returns the value that is mapped to a given 'key'.
int	hashCode()
boolean	isEmpty() Returns 'false' is this map contains key-value mappings (even if some of the values may have been cleared already but not removed from the table).
Set	keySet()
Object	put(Object key, Object value) Updates the table to map 'key' to 'value'.
void	putAll(Map map)
Object	remove(Object key)
int	size() Returns the number of key-value mappings in this map.
String	toString() Overrides Object.toString() for debug purposes.
Collection	values()

从类继承的方法 java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

从接口继承的方法 java.util.Map

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

构造器详细资料

SoftValueMap

public SoftValueMap()

Equivalent to SoftValueMap(1, 1).

SoftValueMap

public SoftValueMap(int readClearCheckFrequency,
                    int writeClearCheckFrequency)

Equivalent to SoftValueMap(11, 0.75F, getClearCheckFrequency, putClearCheckFrequency).

SoftValueMap

public SoftValueMap(int initialCapacity,
                    float loadFactor,
                    int readClearCheckFrequency,
                    int writeClearCheckFrequency)

Constructs a SoftValueMap with specified initial capacity, load factor, and cleared value removal frequencies.

参数:

initialCapacity - initial number of hash buckets in the table [may not be negative, 0 is equivalent to 1].

loadFactor - the load factor to use to determine rehashing points [must be in (0.0, 1.0] range].

readClearCheckFrequency - specifies that every readClearCheckFrequency get(java.lang.Object) should check for and remove all mappings whose soft values have been cleared by the garbage collector [may not be less than 1].

writeClearCheckFrequency - specifies that every writeClearCheckFrequency put(java.lang.Object, java.lang.Object) should check for and remove all mappings whose soft values have been cleared by the garbage collector [may not be less than 1].

方法详细资料

equals

public boolean equals(Object rhs)

指定者:

equals 在接口中 Map

覆盖:

equals 在类中 Object

hashCode

public int hashCode()

指定者:

hashCode 在接口中 Map

覆盖:

hashCode 在类中 Object

toString

public String toString()

Overrides Object.toString() for debug purposes.

覆盖:

toString 在类中 Object

size

public int size()

Returns the number of key-value mappings in this map. Some of the values may have been cleared already but not removed from the table.

NOTE: in contrast with the java.util.WeakHashMap implementation, this is a constant time operation.

指定者:

size 在接口中 Map

isEmpty

public boolean isEmpty()

Returns 'false' is this map contains key-value mappings (even if some of the values may have been cleared already but not removed from the table).

NOTE: in contrast with the java.util.WeakHashMap implementation, this is a constant time operation.

指定者:

isEmpty 在接口中 Map

get

public Object get(Object key)

Returns the value that is mapped to a given 'key'. Returns null if (a) this key has never been mapped or (b) a previously mapped value has been cleared by the garbage collector and removed from the table.

指定者:

get 在接口中 Map

参数:

key - mapping key [may not be null].

返回:

Object value mapping for 'key' [can be null].

put

public Object put(Object key,
                  Object value)

Updates the table to map 'key' to 'value'. Any existing mapping is overwritten.

指定者:

put 在接口中 Map

参数:

key - mapping key [may not be null].

value - mapping value [may not be null].

返回:

Object previous value mapping for 'key' [null if no previous mapping existed or its value has been cleared by the garbage collector and removed from the table].

remove

public Object remove(Object key)

指定者:

remove 在接口中 Map

clear

public void clear()

指定者:

clear 在接口中 Map

containsKey

public boolean containsKey(Object key)

指定者:

containsKey 在接口中 Map

containsValue

public boolean containsValue(Object value)

指定者:

containsValue 在接口中 Map

putAll

public void putAll(Map map)

指定者:

putAll 在接口中 Map

keySet

public Set keySet()

指定者:

keySet 在接口中 Map

entrySet

public Set entrySet()

指定者:

entrySet 在接口中 Map

values

public Collection values()

指定者:

values 在接口中 Map