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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


com.tangosol.util.filter
Class FilterTrigger

java.lang.Object
  extended by com.tangosol.util.Base
      extended by com.tangosol.util.BitHelper
          extended by com.tangosol.util.ExternalizableHelper
              extended by com.tangosol.util.filter.FilterTrigger

All Implemented Interfaces:
ExternalizableLite, PortableObject, MapTrigger, java.io.Serializable

public class FilterTrigger
extends ExternalizableHelper
implements MapTrigger, ExternalizableLite, PortableObject

A generic Filter-based MapTrigger implementation. If an evaluation of the Entry object representing a pending change fails (returns false), then one of the following actions is taken:

Note: This trigger never prevents entries from being removed.

Since:
Coherence 3.4
Author:
gg 2008.03.11

Nested Class Summary

 

Nested classes/interfaces inherited from interface com.tangosol.util.MapTrigger
MapTrigger.Entry

 

Field Summary
static int ACTION_IGNORE
          Evaluation failure results in restoring the original Entry's value.
static int ACTION_REMOVE
          Evaluation failure results in a removal of the entry.
static int ACTION_ROLLBACK
          Evaluation failure results in an IllegalArgumentException thrown by the trigger.
protected  Filter m_filter
          The underlying filter.
protected  int m_nAction
          The action code.

 

Constructor Summary
FilterTrigger()
          Default constructor (necessary for the ExternalizableLite interface).
FilterTrigger(Filter filter)
          Construct a FilterTrigger based on the specified Filter object and ACTION_ROLLBACK.
FilterTrigger(Filter filter, int nAction)
          Construct a FilterTrigger based on the specified Filter object and the action constant.

 

Method Summary
 boolean equals(java.lang.Object o)
          Compare the FilterTrigger with another object to determine equality.
 int getAction()
          Obtain the action code for this FilterTrigger.
 Filter getFilter()
          Obtain the underlying Filter.
 int hashCode()
          Determine a hash value for the FilterTrigger object according to the general Object.hashCode() contract.
 void process(MapTrigger.Entry entry)
          This method is called before the result of a mutating operation represented by the specified Entry object is committed into the underlying map.
 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 FilterTrigger.
 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.

 

Methods inherited from class com.tangosol.util.BitHelper
countBits, countBits, countBits, indexOfLSB, indexOfLSB, indexOfLSB, indexOfMSB, indexOfMSB, indexOfMSB, rotateLeft, rotateLeft, rotateLeft, rotateRight, rotateRight, rotateRight, toBitString, toBitString, toBitString

 

Field Detail

ACTION_ROLLBACK

public static final int ACTION_ROLLBACK
Evaluation failure results in an IllegalArgumentException thrown by the trigger.
See Also:
Constant Field Values

ACTION_IGNORE

public static final int ACTION_IGNORE
Evaluation failure results in restoring the original Entry's value.
See Also:
Constant Field Values

ACTION_REMOVE

public static final int ACTION_REMOVE
Evaluation failure results in a removal of the entry.
See Also:
Constant Field Values

m_filter

protected Filter m_filter
The underlying filter.

m_nAction

protected int m_nAction
The action code.

Constructor Detail

FilterTrigger

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

FilterTrigger

public FilterTrigger(Filter filter)
Construct a FilterTrigger based on the specified Filter object and ACTION_ROLLBACK.
Parameters:
filter - the underlying Filter

FilterTrigger

public FilterTrigger(Filter filter,
                     int nAction)
Construct a FilterTrigger based on the specified Filter object and the action constant.
Parameters:
filter - the underlying Filter
nAction - one of the ACTION_* constants

Method Detail

process

public void process(MapTrigger.Entry entry)
This method is called before the result of a mutating operation represented by the specified Entry object is committed into the underlying map.

An implementation of this method can evaluate the change by analyzing the original and the new value, and can perform any of the following:

Specified by:
process in interface MapTrigger
Parameters:
entry - a MapTrigger.Entry object that represents the pending change to be committed to the map, as well as the original state of the Entry

getFilter

public Filter getFilter()
Obtain the underlying Filter.
Returns:
the underlying Filter object

getAction

public int getAction()
Obtain the action code for this FilterTrigger.
Returns:
one of the ACTION_* constants

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

equals

public boolean equals(java.lang.Object o)
Compare the FilterTrigger with another object to determine equality. Two FilterTrigger objects are considered equal iff the wrapped filters and action codes are equal.
Returns:
true iff this FilterTrigger and the passed object are equivalent FilterTrigger objects

hashCode

public int hashCode()
Determine a hash value for the FilterTrigger object according to the general Object.hashCode() contract.
Returns:
an integer hash value for this FilterTrigger object

toString

public java.lang.String toString()
Return a human-readable description for this FilterTrigger.
Returns:
a String description of the FilterTrigger

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Oracle® Coherence Java API Reference
Release 3.7.0.0

E18683-01


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