com.tangosol.util
Class SafeHashMap.Entry

java.lang.Object
  com.tangosol.util.Base
      com.tangosol.util.SafeHashMap.Entry

All Implemented Interfaces:

Serializable, Cloneable, Map.Entry

Direct Known Subclasses:

ObservableHashMap.Entry, OldCache.Entry

Enclosing class:

SafeHashMap

protected static class SafeHashMap.Entry
extends Base
implements Map.Entry, Cloneable, Serializable

A map entry (key-value pair). The Map.entrySet method returns a collection-view of the map, whose elements are of this class.

Field Summary

protected SafeHashMap.Entry	m_eNext The next entry in the linked list (an open hashing implementation).
protected int	m_nHash The key's hash code.
protected Object	m_oKey The key.
protected Object	m_oValue The value.

Constructor Summary

protected

SafeHashMap.Entry()

Method Summary

Object	clone() Clone the Entry.
protected void	copyFrom(SafeHashMap.Entry entry) Copy this Entry's information from another Entry.
boolean	equals(Object o) Compares the specified object with this entry for equality.
Object	getKey() Returns the key corresponding to this entry.
Object	getValue() Returns the value corresponding to this entry.
int	hashCode() Returns the hash code value for this map entry.
protected void	onAdd() This method is invoked when the containing Map has actually added this Entry to itself.
Object	setValue(Object value) Replaces the value corresponding to this entry with the specified value (optional operation).
String	toString() Render the map entry as a String.

Field Detail

m_oKey

protected Object m_oKey

The key. This object reference will not change for the life of the Entry.

m_oValue

protected volatile Object m_oValue

The value. This object reference can change within the life of the Entry. This field is declared volatile so that get() and put() can proceed without performing any synchronization.

m_nHash

protected int m_nHash

The key's hash code. This value will not change for the life of the Entry.

m_eNext

protected volatile SafeHashMap.Entry m_eNext

The next entry in the linked list (an open hashing implementation). This field is declared volatile so the entry iterator can safely operate without performing any synchronization.

Constructor Detail

SafeHashMap.Entry

protected SafeHashMap.Entry()

Method Detail

getKey

public Object getKey()

Returns the key corresponding to this entry.

Specified by:

getKey in interface Map.Entry

Returns:

the key corresponding to this entry.

getValue

public Object getValue()

Returns the value corresponding to this entry. If the mapping has been removed from the backing map (by the iterator's remove operation), the results of this call are undefined.

Specified by:

getValue in interface Map.Entry

Returns:

the value corresponding to this entry.

setValue

public Object setValue(Object value)

Replaces the value corresponding to this entry with the specified value (optional operation). (Writes through to the map.) The behavior of this call is undefined if the mapping has already been removed from the map (by the iterator's remove operation).

Specified by:

setValue in interface Map.Entry

Parameters:

value - new value to be stored in this entry

Returns:

old value corresponding to the entry

equals

public boolean equals(Object o)

Compares the specified object with this entry for equality. Returns true if the given object is also a map entry and the two entries represent the same mapping. More formally, two entries e1 and e2 represent the same mapping if

     (e1.getKey()==null ?
      e2.getKey()==null : e1.getKey().equals(e2.getKey()))  &&
     (e1.getValue()==null ?
      e2.getValue()==null : e1.getValue().equals(e2.getValue()))
 

This ensures that the equals method works properly across different implementations of the Map.Entry interface.

Specified by:

equals in interface Map.Entry

Parameters:

o - object to be compared for equality with this map entry

Returns:

true if the specified object is equal to this map entry

hashCode

public int hashCode()

Returns the hash code value for this map entry. The hash code of a map entry e is defined to be:

     (e.getKey()==null   ? 0 : e.getKey().hashCode()) ^
     (e.getValue()==null ? 0 : e.getValue().hashCode())
 

This ensures that e1.equals(e2) implies that e1.hashCode()==e2.hashCode() for any two Entries e1 and e2, as required by the general contract of Object.hashCode.

Specified by:

hashCode in interface Map.Entry

Returns:

the hash code value for this map entry.

toString

public String toString()

Render the map entry as a String.

Returns:

the details about this entry

clone

public Object clone()

Clone the Entry. This will not work for non-static inner children being cloned for purposes of cloning a containing Map; instead use copyFrom.

Returns:

a Clone of this entry

copyFrom

protected void copyFrom(SafeHashMap.Entry entry)

Copy this Entry's information from another Entry. Sub-classes must implement this method if they add any additional fields.

Parameters:

entry - the entry to copy from

onAdd

protected void onAdd()

This method is invoked when the containing Map has actually added this Entry to itself.