Oracle® Coherence Java API Reference
v3.5.3

E15583-01

com.tangosol.util
Class SimpleMapEntry

java.lang.Object
  extended by com.tangosol.util.Base
      extended by com.tangosol.util.SimpleMapEntry
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, java.util.Map.Entry
Direct Known Subclasses:
AbstractKeyBasedMap.EntrySet.Entry, BinaryMap.Entry, ReadWriteBackingMap.WriteQueue.Entry, SimpleElement.AttributeMap.Entry

public class SimpleMapEntry
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. The only way to obtain a reference to a map entry is from the iterator of this collection-view. These Map.Entry objects are valid only for the duration of the iteration; more formally, the behavior of a map entry is undefined if the backing map has been modified after the entry was returned by the iterator, except through the iterator's own remove operation, or through the setValue operation on a map entry returned by the iterator.

Author:
cp 2002.02.07

Field Summary
protected  java.lang.Object m_oKey
          The key.
protected  java.lang.Object m_oValue
          The value.
 
Constructor Summary
protected SimpleMapEntry()
          Default constructor.
  SimpleMapEntry(java.util.Map.Entry entry)
          Copy constructor.
protected SimpleMapEntry(java.lang.Object oKey)
          Construct a SimpleMapEntry with just a key.
  SimpleMapEntry(java.lang.Object oKey, java.lang.Object oValue)
          Construct a SimpleMapEntry with a key and a value.
 
Method Summary
 java.lang.Object clone()
          Clone the 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.
 java.lang.Object setValue(java.lang.Object oValue)
          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 java.lang.Object m_oValue
The value. This object reference can change within the life of the Entry.

Constructor Detail

SimpleMapEntry

protected SimpleMapEntry()
Default constructor.


SimpleMapEntry

protected SimpleMapEntry(java.lang.Object oKey)
Construct a SimpleMapEntry with just a key.

Parameters:
oKey - an object for the key

SimpleMapEntry

public SimpleMapEntry(java.util.Map.Entry entry)
Copy constructor.

Parameters:
entry - an entry to copy from

SimpleMapEntry

public SimpleMapEntry(java.lang.Object oKey,
                      java.lang.Object oValue)
Construct a SimpleMapEntry with a key and a value.

Parameters:
oKey - an object for the key
oValue - an object for the value
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 oValue)
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:
oValue - 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.

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.

Returns:
a clone of this Entry

Oracle® Coherence Java API Reference
v3.5.3

E15583-01

Copyright © 2000, 2010, Oracle. All rights reserved.