org.apache.commons.collections.map
Class AbstractReferenceMap.ReferenceEntry

java.lang.Object
  org.apache.commons.collections.map.AbstractHashedMap.HashEntry
      org.apache.commons.collections.map.AbstractReferenceMap.ReferenceEntry

All Implemented Interfaces:

java.util.Map.Entry, KeyValue

Enclosing class:

AbstractReferenceMap

protected static class AbstractReferenceMap.ReferenceEntry
extends AbstractHashedMap.HashEntry

A MapEntry implementation for the map.

If getKey() or getValue() returns null, it means the mapping is stale and should be removed.

Since:

Commons Collections 3.1

Field Summary

protected AbstractReferenceMap

parent The parent map

Fields inherited from class org.apache.commons.collections.map.AbstractHashedMap.HashEntry

hashCode, key, next, value

Constructor Summary

AbstractReferenceMap.ReferenceEntry(AbstractReferenceMap parent, AbstractHashedMap.HashEntry next, int hashCode, java.lang.Object key, java.lang.Object value)
Creates a new entry object for the ReferenceMap.

Method Summary

boolean	equals(java.lang.Object obj) Compares this map entry to another.
java.lang.Object	getKey() Gets the key from the entry.
java.lang.Object	getValue() Gets the value from the entry.
int	hashCode() Gets the hashcode of the entry using temporary hard references.
protected AbstractReferenceMap.ReferenceEntry	next() Gets the next entry in the bucket.
java.lang.Object	setValue(java.lang.Object obj) Sets the value of the entry.
protected java.lang.Object	toReference(int type, java.lang.Object referent, int hash) Constructs a reference of the given type to the given referent.

Methods inherited from class org.apache.commons.collections.map.AbstractHashedMap.HashEntry

toString

Methods inherited from class java.lang.Object

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

Field Detail

parent

protected final AbstractReferenceMap parent

The parent map

Constructor Detail

AbstractReferenceMap.ReferenceEntry

public AbstractReferenceMap.ReferenceEntry(AbstractReferenceMap parent,
                                           AbstractHashedMap.HashEntry next,
                                           int hashCode,
                                           java.lang.Object key,
                                           java.lang.Object value)

Creates a new entry object for the ReferenceMap.

Parameters:

parent - the parent map

next - the next entry in the hash bucket

hashCode - the hash code of the key

key - the key

value - the value

Method Detail

getKey

public java.lang.Object getKey()

Gets the key from the entry. This method dereferences weak and soft keys and thus may return null.

Specified by:

getKey in interface java.util.Map.Entry

Specified by:

getKey in interface KeyValue

Overrides:

getKey in class AbstractHashedMap.HashEntry

Returns:

the key, which may be null if it was garbage collected

getValue

public java.lang.Object getValue()

Gets the value from the entry. This method dereferences weak and soft value and thus may return null.

Specified by:

getValue in interface java.util.Map.Entry

Specified by:

getValue in interface KeyValue

Overrides:

getValue in class AbstractHashedMap.HashEntry

Returns:

the value, which may be null if it was garbage collected

setValue

public java.lang.Object setValue(java.lang.Object obj)

Sets the value of the entry.

Specified by:

setValue in interface java.util.Map.Entry

Overrides:

setValue in class AbstractHashedMap.HashEntry

Parameters:

obj - the object to store

Returns:

the previous value

equals

public boolean equals(java.lang.Object obj)

Compares this map entry to another.

This implementation uses isEqualKey and isEqualValue on the main map for comparison.

Specified by:

equals in interface java.util.Map.Entry

Overrides:

equals in class AbstractHashedMap.HashEntry

Parameters:

obj - the other map entry to compare to

Returns:

true if equal, false if not

hashCode

public int hashCode()

Gets the hashcode of the entry using temporary hard references.

This implementation uses hashEntry on the main map.

Specified by:

hashCode in interface java.util.Map.Entry

Overrides:

hashCode in class AbstractHashedMap.HashEntry

Returns:

the hashcode of the entry

toReference

protected java.lang.Object toReference(int type,
                                       java.lang.Object referent,
                                       int hash)

Constructs a reference of the given type to the given referent. The reference is registered with the queue for later purging.

Parameters:

type - HARD, SOFT or WEAK

referent - the object to refer to

hash - the hash code of the key of the mapping; this number might be different from referent.hashCode() if the referent represents a value and not a key

next

protected AbstractReferenceMap.ReferenceEntry next()

Gets the next entry in the bucket.

Returns:

the next entry in the bucket