org.geotools.filter.spatial

Class AbstractPreparedGeometryFilter

Object

FilterAbstract

AbstractFilter

BinaryComparisonAbstract

GeometryFilterImpl

AbstractPreparedGeometryFilter

All Implemented Interfaces:

FilterType, Filter, MultiValuedFilter, BinarySpatialOperator, SpatialOperator

Direct Known Subclasses:

BBOXImpl, ContainsImpl, DisjointImpl, IntersectsImpl, WithinImpl

public abstract class AbstractPreparedGeometryFilter
extends GeometryFilterImpl

A base class for GeometryFilters that will use PreparedGeometries when the Expression is a Literal Expression.

This class determines when the expressions are set which expressions are literals. The protected field literals contains the AbstractPreparedGeometryFilter.Literals enumerated value that indicates if:

• NEITHER (Literals#NEITHER) of the expressions are literal and is a JTS Geometry (also non-null)
• BOTH ({@link Literals#BOTH}) expressions are literals and is a JTS Geometry (also non-null)
• the LEFT ({@link Literals#LEFT}) expression (Expression1) is a literal and is a JTS Geometry (also non-null)
• or the RIGHT ({@link Literals#RIGHT}) expression (Expression2) is a literal and is a JTS Geometry (also non-null)

If BOTH of the expressions are literals then a cached value is generated by calling {@link #basicEvaluate(Geometry, Geometry)}.

The method {@link #basicEvaluate(Geometry, Geometry)} is required to be implemented so that a cached value can be generated in the case that both expressions are literals

Example usage for intersects filter:

 public boolean evaluate(Object feature) {
 if (feature instanceof SimpleFeature
 && !validate((SimpleFeature) feature)) {
 // we could not obtain a geometry for both left and right hand sides
 // so default to false
 return false;
 }
 Geometry left;
 Geometry right;

 switch (literals) {
 case BOTH:
 return cacheValue;
 case RIGHT: {
 return rightPreppedGeom.intersects(getLeftGeometry(feature));
 }
 case LEFT: {
 return leftPreppedGeom.intersects(getRightGeometry(feature));
 }
 default: {
 left = getLeftGeometry(feature);
 right = getRightGeometry(feature);
 return basicEvaluate(left, right);
 }
 }
 }

 protected final boolean basicEvaluate(Geometry left, Geometry right) {
 Envelope envLeft = left.getEnvelopeInternal();
 Envelope envRight = right.getEnvelopeInternal();
 return envRight.intersects(envLeft) && left.intersects(right);
 }
 

Author:

jesse

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	AbstractPreparedGeometryFilter.Literals Constant that identifies which expressions are Literal and JTS Geometries

Nested classes/interfaces inherited from interface MultiValuedFilter

MultiValuedFilter.MatchAction

Field Summary

Fields

Modifier and Type	Field and Description
protected boolean	cacheValue If both expressions are literals the value will never change.
protected PreparedGeometry	leftPreppedGeom The PreparedGeometry for the left Geometry.
protected AbstractPreparedGeometryFilter.Literals	literals Indicates which expressions are Literals
protected PreparedGeometry	rightPreppedGeom The PreparedGeometry for the right Geometry.

Fields inherited from class GeometryFilterImpl

matchAction

Fields inherited from class BinaryComparisonAbstract

expression1, expression2

Fields inherited from class AbstractFilter

LOGGER

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	AbstractPreparedGeometryFilter(Expression e1, Expression e2)
protected	AbstractPreparedGeometryFilter(Expression e1, Expression e2, MultiValuedFilter.MatchAction matchAction)

Method Summary

Modifier and Type	Method and Description
protected abstract boolean	basicEvaluate(Geometry left, Geometry right) Performs the calculation on the two geometries.
void	setExpression1(Expression expression)
void	setExpression2(Expression expression)

Methods inherited from class GeometryFilterImpl

equals, evaluate, evaluateInternal, getGeometries, getMatchAction, hashCode, toString

Methods inherited from class BinaryComparisonAbstract

comparable, eval, eval, getExpression1, getExpression2, 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 BinarySpatialOperator

getExpression1, getExpression2

Methods inherited from interface Filter

accept

Field Detail

literals

protected AbstractPreparedGeometryFilter.Literals literals

Indicates which expressions are Literals

leftPreppedGeom

protected PreparedGeometry leftPreppedGeom

The PreparedGeometry for the left Geometry. Null if the left geometry is not a Literal

rightPreppedGeom

protected PreparedGeometry rightPreppedGeom

The PreparedGeometry for the right Geometry. Null if the right geometry is not a Literal

cacheValue

protected boolean cacheValue

If both expressions are literals the value will never change. In that case this field is that calculated value. It is false otherwise.

Constructor Detail

AbstractPreparedGeometryFilter

protected AbstractPreparedGeometryFilter(Expression e1,
                                         Expression e2)

AbstractPreparedGeometryFilter

protected AbstractPreparedGeometryFilter(Expression e1,
                                         Expression e2,
                                         MultiValuedFilter.MatchAction matchAction)

Method Detail

setExpression1

public void setExpression1(Expression expression)

Overrides:

setExpression1 in class BinaryComparisonAbstract

setExpression2

public void setExpression2(Expression expression)

Overrides:

setExpression2 in class BinaryComparisonAbstract

basicEvaluate

protected abstract boolean basicEvaluate(Geometry left,
                                         Geometry right)

Performs the calculation on the two geometries. This is used to calculate the cached value in the case that both geometries are Literals. But in practice it is useful to extract this functionality into its own method.

Parameters:

left - the geometry on the left of the equations (the geometry obtained from evaluating Expression1)

right - the geometry on the right of the equations (the geometry obtained from evaluating Expression2)

Returns:

true if the filter evaluates to true for the two geometries