org.geotools.filter

Class CompareFilterImpl

Object

FilterAbstract

AbstractFilter

BinaryComparisonAbstract

CompareFilterImpl

All Implemented Interfaces:

FilterType, Filter, MultiValuedFilter

Direct Known Subclasses:

IsBetweenImpl, IsNilImpl, IsNullImpl, MultiCompareFilterImpl

public abstract class CompareFilterImpl
extends BinaryComparisonAbstract

Defines a comparison filter (can be a math comparison or generic equals). This filter implements a comparison - of some sort - between two expressions. The comparison may be a math comparison or a generic equals comparison. If it is a math comparison, only math expressions are allowed; if it is an equals comparison, any expression types are allowed. Note that this comparison does not attempt to restrict its expressions to be meaningful. This means that it considers itself a valid filter as long as the expression comparison returns a valid result. It does no checking to see whether or not the expression comparison is meaningful with regard to checking feature attributes. In other words, this is a valid filter: 52 = 92, even though it will always return the same result and could be simplified away. It is up the the filter creator, therefore, to attempt to simplify/make meaningful filter logic.

Author:

Rob Hranac, Vision for New York

Nested Class Summary

Nested classes/interfaces inherited from interface MultiValuedFilter

MultiValuedFilter.MatchAction

Field Summary

Fields inherited from class BinaryComparisonAbstract

expression1, expression2

Fields inherited from interface Filter

EXCLUDE, INCLUDE

Fields inherited from interface FilterType

ALL, 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, NONE, NULL

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	CompareFilterImpl(Expression e1, Expression e2)
protected	CompareFilterImpl(Expression e1, Expression e2, boolean matchCase)

Method Summary

Modifier and Type	Method and Description
abstract Object	accept(FilterVisitor visitor, Object extraData) Used by FilterVisitors to perform some action on this filter instance.
protected int	compare(Comparable leftObj, Comparable rightObj) Subclass convenience method which compares to instances of comparables in a pretty lax way, converting types among String, Number, Double when appropriate.
boolean	equals(Object obj) Compares this filter to the specified object.
int	hashCode() Override of hashCode method.
void	setExpression1(Expression leftValue)
void	setExpression2(Expression rightValue)
String	toString() Returns a string representation of this filter.

Methods inherited from class BinaryComparisonAbstract

comparable, eval, eval, getExpression1, getExpression2, getMatchAction, isMatchingCase

Methods inherited from class AbstractFilter

isCompareFilter, isGeometryDistanceFilter, isGeometryFilter, isLogicFilter, isMathFilter, isSimpleFilter

Methods inherited from class FilterAbstract

accepts, eval, eval

Methods inherited from class Object

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

Methods inherited from interface Filter

evaluate

Constructor Detail

CompareFilterImpl

protected CompareFilterImpl(Expression e1,
                            Expression e2)

CompareFilterImpl

protected CompareFilterImpl(Expression e1,
                            Expression e2,
                            boolean matchCase)

Method Detail

setExpression1

public void setExpression1(Expression leftValue)

Overrides:

setExpression1 in class BinaryComparisonAbstract

setExpression2

public void setExpression2(Expression rightValue)

Overrides:

setExpression2 in class BinaryComparisonAbstract

compare

protected int compare(Comparable leftObj,
                      Comparable rightObj)

Subclass convenience method which compares to instances of comparables in a pretty lax way, converting types among String, Number, Double when appropriate.

Returns:

same contract as Comparable.compareTo(java.lang.Object).

toString

public String toString()

Returns a string representation of this filter.

Overrides:

toString in class Object

Returns:

String representation of the compare filter.

equals

public boolean equals(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 are the same as well as both of the values.

Overrides:

equals in class Object

Parameters:

obj - - the object to compare this CompareFilter against.

Returns:

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

hashCode

public int hashCode()

Override of hashCode method.

Overrides:

hashCode in class Object

Returns:

a code to hash this object by.

accept

public abstract Object accept(FilterVisitor visitor,
                              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.

Parameters:

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