com.ibm.websphere.objectgrid.continuousquery.filter
Class AbstractCQFilter<KeyType,ValueType,AttributeType,MatchType>

java.lang.Object
  com.ibm.websphere.objectgrid.continuousquery.filter.AbstractCQFilter<KeyType,ValueType,AttributeType,MatchType>

Type Parameters:

KeyType - Type of the key object for the map being queried

ValueType - Type of the value object for the map being queried

AttributeType - Type of the attribute referenced by the attribute path

MatchType - Type of the object being compared to

All Implemented Interfaces:

ContinuousQueryFilter<KeyType,ValueType,AttributeType,MatchType>, Serializable

Direct Known Subclasses:

BinaryLogicalFilter, CompareFilter, FalseFilter, IsNotNullFilter, IsNullFilter, NotFilter, TrueFilter

public abstract class AbstractCQFilter<KeyType,ValueType,AttributeType,MatchType>
extends Object
implements ContinuousQueryFilter<KeyType,ValueType,AttributeType,MatchType>

This is an abstract class which all continuous query filters must extend. It defines how cached entries should be compared and filtered. All subclasses must provide a no-argument constructor for serialization purposes.

Since:

8.6

See Also:

Serialized Form

Field Summary

protected int

version Version of the filter implementation, which can be used internally for backward compatibility.

Fields inherited from interface com.ibm.websphere.objectgrid.continuousquery.ContinuousQueryFilter

POJO_ADDRESSABLEKEYNAME, POJO_PATHSEPARATOR

Constructor Summary

AbstractCQFilter()

Method Summary

abstract String	createString() Creates a string representation of the continuous query filter, this method is used by toString().
boolean	equals(Object obj)
protected Object	getAttribute(FilterContent content, String attributePath) Retrieves an attribute from the content that is to be filtered based on the specified attribute path.
int	hashCode()
boolean	isKeyFilter()
String	toString()
protected void	validateAttributePath(String attributePath) Ensure that attribute path used to retrieve an attribute from a cache entry is valid.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface com.ibm.websphere.objectgrid.continuousquery.ContinuousQueryFilter

filter

Field Detail

version

protected int version

Version of the filter implementation, which can be used internally for backward compatibility. The version can be used to, for example, determine what filtering logic should be used, how serialization/inflation should be done, etc. Version 1 filters are shipped with WebSphere eXtreme Scale 8.6.0.0.

Constructor Detail

AbstractCQFilter

public AbstractCQFilter()

Method Detail

isKeyFilter

public boolean isKeyFilter()

createString

public abstract String createString()

Creates a string representation of the continuous query filter, this method is used by toString().

The string will be used for identifying and comparing filters, i.e. it will be used in hashCode() and equals(Object), so the returned value must be in unique format among all filters in the system.

Returns:

an unique string representation of the filter

equals

public boolean equals(Object obj)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object

validateAttributePath

protected void validateAttributePath(String attributePath)
                              throws ContinuousQueryAttributePathException

Ensure that attribute path used to retrieve an attribute from a cache entry is valid.

Parameters:

attributePath - the path to the attribute

Throws:

ContinuousQueryAttributePathException

getAttribute

protected Object getAttribute(FilterContent content,
                              String attributePath)
                       throws ContinuousQueryException

Retrieves an attribute from the content that is to be filtered based on the specified attribute path.

Parameters:

content - The cache entry (key and value) to be processed by this filter

attributePath - the path specifying the attribute of this cache entry to be examined. For a description of attribute paths, @see CompareFilter#CompareFilter(String, Object)

Returns:

the attribute specified by the attributePath, extracted from the cache entry represented by the FilterContent instance.

Throws:

ContinuousQueryException