org.geotools.filter
Class CompareFilterImpl

java.lang.Object
  org.geotools.filter.FilterAbstract
      org.geotools.filter.AbstractFilter
          org.geotools.filter.BinaryComparisonAbstract
              org.geotools.filter.CompareFilterImpl

All Implemented Interfaces:

org.opengis.filter.BinaryComparisonOperator, CompareFilter, Filter, org.opengis.filter.Filter, FilterType

Direct Known Subclasses:

BetweenFilterImpl, IsEqualsToImpl, IsGreaterThanImpl, IsGreaterThanOrEqualToImpl, IsLessThenImpl, IsLessThenOrEqualToImpl, IsNotEqualToImpl

public abstract class CompareFilterImpl

extends BinaryComparisonAbstract

implements CompareFilter

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.

Version:

$Id: CompareFilterImpl.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.BinaryComparisonAbstract

expression1, expression2

Fields inherited from class org.geotools.filter.AbstractFilter

filterType, 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	CompareFilterImpl(FilterFactory factory, org.opengis.filter.expression.Expression e1, org.opengis.filter.expression.Expression e2)
protected	CompareFilterImpl(short filterType) Constructor with filter type.

Method Summary

abstract java.lang.Object	accept(org.opengis.filter.FilterVisitor visitor, java.lang.Object extraData) Used by FilterVisitors to perform some action on this filter instance.
void	addLeftValue(Expression leftValue) Adds the 'left' value to this filter.
void	addRightValue(Expression rightValue) Adds the 'right' value to this filter.
protected int	compare(java.lang.Comparable leftObj, java.lang.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(java.lang.Object obj) Compares this filter to the specified object.
abstract boolean	evaluate(Feature feature) Determines whether or not a given feature is 'inside' this filter.
Expression	getLeftValue() Gets the left expression.
Expression	getRightValue() Deprecated. use BinaryComparisonAbstract.getExpression2()
int	hashCode() Override of hashCode method.
void	setExpression1(org.opengis.filter.expression.Expression leftValue)
void	setExpression2(org.opengis.filter.expression.Expression rightValue)
java.lang.String	toString() Returns a string representation of this filter.

Methods inherited from class org.geotools.filter.BinaryComparisonAbstract

and, getExpression1, getExpression2, 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.CompareFilter

contains

Methods inherited from interface org.geotools.filter.Filter

accept, and, getFilterType, not, or

Methods inherited from interface org.opengis.filter.Filter

evaluate

Methods inherited from interface org.opengis.filter.BinaryComparisonOperator

getExpression1, getExpression2

Constructor Detail

CompareFilterImpl

protected CompareFilterImpl(short filterType)
                     throws IllegalFilterException

Constructor with filter type.

Parameters:

filterType - The type of comparison.

Throws:

IllegalFilterException - Non-compare type.

CompareFilterImpl

protected CompareFilterImpl(FilterFactory factory,
                            org.opengis.filter.expression.Expression e1,
                            org.opengis.filter.expression.Expression e2)

Method Detail

addLeftValue

public final void addLeftValue(Expression leftValue)
                        throws IllegalFilterException

Adds the 'left' value to this filter.

Specified by:

addLeftValue in interface CompareFilter

Parameters:

leftValue - Expression for 'left' value.

Throws:

IllegalFilterException - Filter is not internally consistent.

Task:

REVISIT: immutability?

setExpression1

public void setExpression1(org.opengis.filter.expression.Expression leftValue)

Specified by:

setExpression1 in interface org.opengis.filter.BinaryComparisonOperator

Overrides:

setExpression1 in class BinaryComparisonAbstract

addRightValue

public final void addRightValue(Expression rightValue)
                         throws IllegalFilterException

Adds the 'right' value to this filter.

Specified by:

addRightValue in interface CompareFilter

Parameters:

rightValue - Expression for 'right' value.

Throws:

IllegalFilterException - Filter is not internally consistent.

Task:

REVISIT: make immutable.

setExpression2

public void setExpression2(org.opengis.filter.expression.Expression rightValue)

Specified by:

setExpression2 in interface org.opengis.filter.BinaryComparisonOperator

Overrides:

setExpression2 in class BinaryComparisonAbstract

getLeftValue

public final Expression getLeftValue()

Gets the left expression.

Specified by:

getLeftValue in interface CompareFilter

Returns:

The expression on the left of the comparison. * @deprecated use BinaryComparisonAbstract.getExpression1()

getRightValue

public final Expression getRightValue()

Deprecated. use BinaryComparisonAbstract.getExpression2()

Gets the right expression.

Specified by:

getRightValue in interface CompareFilter

Returns:

The expression on the right of the comparison.

evaluate

public abstract 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.

compare

protected int compare(java.lang.Comparable leftObj,
                      java.lang.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 java.lang.String toString()

Returns a string representation of this filter.

Returns:

String representation of the compare 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 are the same as well as both of the values.

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.

Returns:

a code to hash this object by.

accept

public abstract 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);