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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


com.tangosol.util
Class SafeHashMap.Entry

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

All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, java.util.Map.Entry
Direct Known Subclasses:
ObservableHashMap.Entry, OldCache.Entry
Enclosing class:
SafeHashMap

protected static class SafeHashMap.Entry
extends Base
implements java.util.Map.Entry, java.lang.Cloneable, java.io.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  java.lang.Object m_oKey
          The key.
protected  java.lang.Object m_oValue
          The value.

 

Constructor Summary
protected SafeHashMap.Entry()
           

 

Method Summary
 java.lang.Object clone()
          Clone the Entry.
protected  void copyFrom(SafeHashMap.Entry entry)
          Copy this Entry's information from another Entry.
 boolean equals(java.lang.Object o)
          Compares the specified object with this entry for equality.
 java.lang.Object getKey()
          Returns the key corresponding to this entry.
 java.lang.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.
 java.lang.Object setValue(java.lang.Object value)
          Replaces the value corresponding to this entry with the specified value (optional operation).
 java.lang.String toString()
          Render the map entry as a String.

 

Field Detail

m_oKey

protected java.lang.Object m_oKey
The key. This object reference will not change for the life of the Entry.

m_oValue

protected volatile java.lang.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 java.lang.Object getKey()
Returns the key corresponding to this entry.
Specified by:
getKey in interface java.util.Map.Entry
Returns:
the key corresponding to this entry.

getValue

public java.lang.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 java.util.Map.Entry
Returns:
the value corresponding to this entry.

setValue

public java.lang.Object setValue(java.lang.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 java.util.Map.Entry
Parameters:
value - new value to be stored in this entry
Returns:
old value corresponding to the entry

equals

public boolean equals(java.lang.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 java.util.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 java.util.Map.Entry
Returns:
the hash code value for this map entry.
See Also:
Object.hashCode(), Object.equals(Object), Map.Entry.equals(Object)

toString

public java.lang.String toString()
Render the map entry as a String.
Returns:
the details about this entry

clone

public java.lang.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.

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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


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