org.geotools.filter

Class AttributeExpressionImpl

Object

ExpressionAbstract

DefaultExpression

AttributeExpressionImpl

All Implemented Interfaces:

Expression, PropertyName

Direct Known Subclasses:

JoinPropertyName, NestedAttributeExpression

public class AttributeExpressionImpl
extends DefaultExpression
implements PropertyName

Defines a complex filter (could also be called logical filter). This filter holds one or more filters together and relates them logically in an internally defined manner.

Author:

Rob Hranac, TOPP

Field Summary

Fields

Modifier and Type	Field and Description
protected String	attPath Holds all sub filters of this filter.
protected boolean	lenient Configures whether evaluate should return null if it cannot find a working property accessor, rather than throwing an exception (default behaviour).
protected SimpleFeatureType	schema Used to validate attribute references to ensure they match the provided schema

Fields inherited from interface Expression

NIL

Constructor Summary

Constructors

Modifier	Constructor and Description
	AttributeExpressionImpl(Name name) Constructor with full attribute name.
protected	AttributeExpressionImpl(SimpleFeatureType schema) Constructor with the schema for this attribute.
protected	AttributeExpressionImpl(SimpleFeatureType schema, String attPath) Constructor with schema and path to the attribute.
	AttributeExpressionImpl(String xpath) Constructor with schema and path to the attribute.
	AttributeExpressionImpl(String xpath, Hints hints)
	AttributeExpressionImpl(String xpath, NamespaceSupport namespaceContext) Constructor with schema and path to the attribute.

Method Summary

Modifier and Type	Method and Description
Object	accept(ExpressionVisitor visitor, Object extraData) Used by FilterVisitors to perform some action on this filter instance.
boolean	equals(Object obj) Compares this filter to the specified object.
Object	evaluate(Object obj) Gets the value of this property from the passed object.
<T> T	evaluate(Object obj, Class<T> target) Gets the value of this attribute from the passed object.
NamespaceSupport	getNamespaceContext() Returns namespace context information, or null if unavailable/inapplicable
String	getPropertyName() Gets the path to the attribute to be evaluated by this expression.
int	hashCode() Override of hashCode method.
boolean	isLenient() Gets lenient property
void	setLenient(boolean lenient) Sets lenient property.
void	setPropertyName(String attPath)
String	toString() Return this expression as a string.

Methods inherited from class DefaultExpression

isAttributeExpression, isExpression, isFunctionExpression, isGeometryExpression, isLiteralExpression, isMathExpression

Methods inherited from class Object

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

Field Detail

attPath

protected String attPath

Holds all sub filters of this filter.

schema

protected SimpleFeatureType schema

Used to validate attribute references to ensure they match the provided schema

lenient

protected boolean lenient

Configures whether evaluate should return null if it cannot find a working property accessor, rather than throwing an exception (default behaviour).

Constructor Detail

AttributeExpressionImpl

protected AttributeExpressionImpl(SimpleFeatureType schema)

Constructor with the schema for this attribute.

Parameters:

schema - The schema for this attribute.

AttributeExpressionImpl

public AttributeExpressionImpl(String xpath)

Constructor with schema and path to the attribute.

Parameters:

xpath - the String xpath to the attribute.

AttributeExpressionImpl

public AttributeExpressionImpl(Name name)

Constructor with full attribute name.

Parameters:

name - Attribute Name.

AttributeExpressionImpl

public AttributeExpressionImpl(String xpath,
                               NamespaceSupport namespaceContext)

Constructor with schema and path to the attribute.

Parameters:

xpath - the String xpath to the attribute.

namespaceContext - Defining the prefix information for the xpath expression

AttributeExpressionImpl

public AttributeExpressionImpl(String xpath,
                               Hints hints)

Parameters:

xpath - xpath expression

hints - Hints passed to the property accessor during evaulation

AttributeExpressionImpl

protected AttributeExpressionImpl(SimpleFeatureType schema,
                                  String attPath)
                           throws IllegalFilterException

Constructor with schema and path to the attribute.

Parameters:

schema - The initial (required) sub filter.

attPath - the xpath to the attribute.

Throws:

IllegalFilterException - If the attribute path is not in the schema.

Method Detail

getNamespaceContext

public NamespaceSupport getNamespaceContext()

Description copied from interface: PropertyName

Returns namespace context information, or null if unavailable/inapplicable

Specified by:

getNamespaceContext in interface PropertyName

Returns:

namespace context information, or null if unavailable/inapplicable

getPropertyName

public String getPropertyName()

Gets the path to the attribute to be evaluated by this expression.

PropertyName.getPropertyName()

Specified by:

getPropertyName in interface PropertyName

setPropertyName

public void setPropertyName(String attPath)

evaluate

public Object evaluate(Object obj)

Gets the value of this property from the passed object.

Specified by:

evaluate in interface Expression

Overrides:

evaluate in class ExpressionAbstract

Parameters:

obj - Object from which we need to extract a property value.

Returns:

default implementation returns null

evaluate

public <T> T evaluate(Object obj,
                      Class<T> target)

Gets the value of this attribute from the passed object.

Specified by:

evaluate in interface Expression

Overrides:

evaluate in class ExpressionAbstract

Type Parameters:

T - The type of the returned object.

Parameters:

obj - Object from which to extract attribute value.

target - Target Class

Returns:

Evaluates the given expression based on the content of the given object an an instance of context.

toString

public String toString()

Return this expression as a string.

Overrides:

toString in class Object

Returns:

String representation of this attribute expression.

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 expression. Checks to make sure the expression types are the same as well as the attribute paths and schemas.

Overrides:

equals in class Object

Parameters:

obj - - the object to compare this ExpressionAttribute against.

Returns:

true if specified object is equal to this filter; else false

hashCode

public int hashCode()

Override of hashCode method.

Overrides:

hashCode in class Object

Returns:

a code to hash this object by.

accept

public Object accept(ExpressionVisitor 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.

Specified by:

accept in interface Expression

Parameters:

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

setLenient

public void setLenient(boolean lenient)

Sets lenient property.

Parameters:

lenient -

isLenient

public boolean isLenient()

Gets lenient property

Returns:

lenient