org.geotools.filter
Class NullFilterImpl

java.lang.Object
  org.geotools.filter.FilterAbstract
      org.geotools.filter.AbstractFilter
          org.geotools.filter.AbstractFilterImpl
              org.geotools.filter.NullFilterImpl

All Implemented Interfaces:

Filter, org.opengis.filter.Filter, FilterType, NullFilter, org.opengis.filter.PropertyIsNull

public class NullFilterImpl

extends AbstractFilterImpl

implements NullFilter

Defines a null filter, which checks to see if an attribute is null.

Version:

$Id: NullFilterImpl.java 18021 2006-02-14 20:36:18Z jdeolive $

Author:

Rob Hranac, Vision for New York

Field Summary

Fields inherited from class org.geotools.filter.AbstractFilter

filterType, LOGGER, permissiveConstruction

Fields inherited from interface org.geotools.filter.Filter

ALL, NONE

Fields inherited from interface org.geotools.filter.FilterType

BETWEEN, COMPARE_EQUALS, COMPARE_GREATER_THAN, COMPARE_GREATER_THAN_EQUAL, COMPARE_LESS_THAN, COMPARE_LESS_THAN_EQUAL, COMPARE_NOT_EQUALS, FID, GEOMETRY_BBOX, GEOMETRY_BEYOND, GEOMETRY_CONTAINS, GEOMETRY_CROSSES, GEOMETRY_DISJOINT, GEOMETRY_DWITHIN, GEOMETRY_EQUALS, GEOMETRY_INTERSECTS, GEOMETRY_OVERLAPS, GEOMETRY_TOUCHES, GEOMETRY_WITHIN, LIKE, LOGIC_AND, LOGIC_NOT, LOGIC_OR, NULL

Constructor Summary

protected

NullFilterImpl() Constructor which sets the type as null check.

Method Summary

java.lang.Object	accept(org.opengis.filter.FilterVisitor visitor, java.lang.Object extraData) Used by FilterVisitors to perform some action on this filter instance.
boolean	equals(java.lang.Object obj) Compares this filter to the specified object.
boolean	evaluate(Feature feature) Determines whether or not a given feature is 'inside' this filter.
org.opengis.filter.expression.Expression	getExpression() Returns the expression which represents the null check.
Expression	getNullCheckValue() Deprecated. use getExpression().
int	hashCode() Override of hashCode method.
void	nullCheckValue(Expression nullCheck) Deprecated. use PropertyIsNull.setExpression(Expression)
void	setExpression(org.opengis.filter.expression.Expression nullCheck) Sets the expression which represents the null check.
java.lang.String	toString() Returns a string representation of this filter.

Methods inherited from class org.geotools.filter.AbstractFilterImpl

and, not, or

Methods inherited from class org.geotools.filter.AbstractFilter

accept, contains, evaluate, getFilterType, isCompareFilter, isGeometryDistanceFilter, isGeometryFilter, isLogicFilter, isMathFilter, isSimpleFilter

Methods inherited from class org.geotools.filter.FilterAbstract

accepts, comparable, eval, eval

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.geotools.filter.NullFilter

contains

Methods inherited from interface org.geotools.filter.Filter

accept, and, getFilterType, not, or

Methods inherited from interface org.opengis.filter.Filter

evaluate

Constructor Detail

NullFilterImpl

protected NullFilterImpl()

Constructor which sets the type as null check.

Method Detail

nullCheckValue

public final void nullCheckValue(Expression nullCheck)
                          throws IllegalFilterException

Deprecated. use PropertyIsNull.setExpression(Expression)

Determines whether or not a given feature is 'inside' this filter.

Specified by:

nullCheckValue in interface NullFilter

Parameters:

nullCheck - The attribute expression to null check.

Throws:

IllegalFilterException - If attempting to add a non-attribute expression.

Task:

REVISIT: change arg to AttributeExpression?, REVISIT: change name to setNullCheckValue.

getNullCheckValue

public final Expression getNullCheckValue()

Deprecated. use getExpression().

Returns the expression being checked for null.

Specified by:

getNullCheckValue in interface NullFilter

Returns:

the Expression to null check.

getExpression

public org.opengis.filter.expression.Expression getExpression()

Returns the expression which represents the null check.

Specified by:

getExpression in interface org.opengis.filter.PropertyIsNull

setExpression

public void setExpression(org.opengis.filter.expression.Expression nullCheck)

Sets the expression which represents the null check.

Specified by:

setExpression in interface org.opengis.filter.PropertyIsNull

evaluate

public boolean evaluate(Feature feature)

Determines whether or not a given feature is 'inside' this filter.

Specified by:

evaluate in interface Filter

Overrides:

evaluate in class FilterAbstract

Parameters:

feature - Specified feature to examine.

Returns:

Flag confirming whether or not this feature is inside the filter.

toString

public java.lang.String toString()

Returns a string representation of this filter.

Returns:

String representation of the null filter.

equals

public boolean equals(java.lang.Object obj)

Compares this filter to the specified object. Returns true if the passed in object is the same as this filter. Checks to make sure the filter types, and the NullCheckValue are the same.

Parameters:

obj - - the object to compare this LikeFilter against.

Returns:

true if specified object is equal to this filter; false otherwise.

hashCode

public int hashCode()

Override of hashCode method.

Returns:

a hash code value for this geometry filter.

accept

public java.lang.Object accept(org.opengis.filter.FilterVisitor visitor,
                               java.lang.Object extraData)

Used by FilterVisitors to perform some action on this filter instance. Typicaly used by Filter decoders, but may also be used by any thing which needs infomration from filter structure. Implementations should always call: visitor.visit(this); It is importatant that this is not left to a parent class unless the parents API is identical.

Specified by:

accept in interface org.opengis.filter.Filter

Overrides:

accept in class FilterAbstract

Parameters:

visitor - The visitor which requires access to this filter, the method must call visitor.visit(this);