Oracle® Coherence Java API Reference
v3.5.3

E15583-01

com.tangosol.util.processor
Class ConditionalPutAll

java.lang.Object
  extended by com.tangosol.util.Base
      extended by com.tangosol.util.processor.AbstractProcessor
          extended by com.tangosol.util.processor.ConditionalPutAll
All Implemented Interfaces:
ExternalizableLite, PortableObject, InvocableMap.EntryProcessor, java.io.Serializable

public class ConditionalPutAll
extends AbstractProcessor
implements ExternalizableLite, PortableObject

ConditionalPutAll is an EntryProcessor that performs a Entry.setValue operation for multiple entries that satisfy the specified condition.

Consider such methods of the ConcurrentMap interface as replace(key, value) and putIfAbsent(key, value). While the regular put(key, value) method has the "multi-put" flavor putAll(map), there are no analogous "bulk" operations for those ConcurrentMap methods. The ConditionalPutAll processor provides the corresponding functionality when used in conjunction with the invokeAll(keys, processor) API. For example, the replaceAll(map) method could be implemented as:

   filter = PresentFilter.INSTANCE;
   cache.invokeAll(map.keySet(), new ConditionalPutAll(filter, map));
 
and the putAllIfAbsent(map) could be done by inverting the filter:
   filter = new NotFilter(PresentFilter.INSTANCE);
 

Obviously, using more specific, fine-tuned filters may provide additional flexibility and efficiency allowing the multi-put operations to be performed conditionally on values of specific attributes (or even calculations) instead of a simple existence check.

Since:
Coherence 3.2
Author:
gg 2006.04.28

Field Summary
protected  Filter m_filter
          The underlying filter.
protected  java.util.Map m_map
          Specifies the map of new values.
 
Constructor Summary
ConditionalPutAll()
          Default constructor (necessary for the ExternalizableLite interface).
ConditionalPutAll(Filter filter, java.util.Map map)
          Construct a ConditionalPutAll processor that updates an entry with a new value if and only if the filter applied to the entry evaluates to true.
 
Method Summary
 boolean equals(java.lang.Object o)
          Compare the ConditionalPutAll with another object to determine equality.
 int hashCode()
          Determine a hash value for the ConditionalPutAll object according to the general Object.hashCode() contract.
 java.lang.Object process(InvocableMap.Entry entry)
          Process a Map.Entry object.
 java.util.Map processAll(java.util.Set setEntries)
          Process a Set of InvocableMap.Entry objects. This method is semantically equivalent to:
   Map mapResults = new ListMap();
   for (Iterator iter = setEntries.iterator(); iter.hasNext(); )
       {
       Entry entry = (Entry) iter.next();
       mapResults.put(entry.getKey(), process(entry));
       }
   return mapResults;
 
 void readExternal(java.io.DataInput in)
          Restore the contents of this object by loading the object's state from the passed DataInput object.
 void readExternal(PofReader in)
          Restore the contents of a user type instance by reading its state using the specified PofReader object.
 java.lang.String toString()
          Return a human-readable description for this ConditionalPutAll.
 void writeExternal(java.io.DataOutput out)
          Save the contents of this object by storing the object's state into the passed DataOutput object.
 void writeExternal(PofWriter out)
          Save the contents of a POF user type instance by writing its state using the specified PofWriter object.
 

Field Detail

m_filter

protected Filter m_filter
The underlying filter.


m_map

protected java.util.Map m_map
Specifies the map of new values.

Constructor Detail

ConditionalPutAll

public ConditionalPutAll()
Default constructor (necessary for the ExternalizableLite interface).


ConditionalPutAll

public ConditionalPutAll(Filter filter,
                         java.util.Map map)
Construct a ConditionalPutAll processor that updates an entry with a new value if and only if the filter applied to the entry evaluates to true. The new value is extracted from the specified map based on the entry's key.

Parameters:
filter - the filter to evaluate all supplied entries
map - a map of values to update entries with
Method Detail

process

public java.lang.Object process(InvocableMap.Entry entry)
Process a Map.Entry object.

Specified by:
process in interface InvocableMap.EntryProcessor
Parameters:
entry - the Entry to process
Returns:
the result of the processing, if any

processAll

public java.util.Map processAll(java.util.Set setEntries)
Process a Set of InvocableMap.Entry objects. This method is semantically equivalent to:
   Map mapResults = new ListMap();
   for (Iterator iter = setEntries.iterator(); iter.hasNext(); )
       {
       Entry entry = (Entry) iter.next();
       mapResults.put(entry.getKey(), process(entry));
       }
   return mapResults;
 

Specified by:
processAll in interface InvocableMap.EntryProcessor
Overrides:
processAll in class AbstractProcessor
Parameters:
setEntries - a read-only Set of InvocableMap.Entry objects to process
Returns:
a Map containing the results of the processing, up to one entry for each InvocableMap.Entry that was processed, keyed by the keys of the Map that were processed, with a corresponding value being the result of the processing for each key

equals

public boolean equals(java.lang.Object o)
Compare the ConditionalPutAll with another object to determine equality.

Returns:
true iff this ConditionalPutAll and the passed object are equivalent ConditionalPutAll

hashCode

public int hashCode()
Determine a hash value for the ConditionalPutAll object according to the general Object.hashCode() contract.

Returns:
an integer hash value for this ConditionalPutAll object

toString

public java.lang.String toString()
Return a human-readable description for this ConditionalPutAll.

Returns:
a String description of the ConditionalPutAll

readExternal

public void readExternal(java.io.DataInput in)
                  throws java.io.IOException
Restore the contents of this object by loading the object's state from the passed DataInput object.

Specified by:
readExternal in interface ExternalizableLite
Parameters:
in - the DataInput stream to read data from in order to restore the state of this object
Throws:
java.io.IOException - if an I/O exception occurs
java.io.NotActiveException - if the object is not in its initial state, and therefore cannot be deserialized into

writeExternal

public void writeExternal(java.io.DataOutput out)
                   throws java.io.IOException
Save the contents of this object by storing the object's state into the passed DataOutput object.

Specified by:
writeExternal in interface ExternalizableLite
Parameters:
out - the DataOutput stream to write the state of this object to
Throws:
java.io.IOException - if an I/O exception occurs

readExternal

public void readExternal(PofReader in)
                  throws java.io.IOException
Restore the contents of a user type instance by reading its state using the specified PofReader object.

Specified by:
readExternal in interface PortableObject
Parameters:
in - the PofReader from which to read the object's state
Throws:
java.io.IOException - if an I/O error occurs

writeExternal

public void writeExternal(PofWriter out)
                   throws java.io.IOException
Save the contents of a POF user type instance by writing its state using the specified PofWriter object.

Specified by:
writeExternal in interface PortableObject
Parameters:
out - the PofWriter to which to write the object's state
Throws:
java.io.IOException - if an I/O error occurs

Oracle® Coherence Java API Reference
v3.5.3

E15583-01

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