Package org.apache.sis.filter

Class UnaryFunction.IsNull<R>

java.lang.Object

org.apache.sis.internal.filter.Node

org.apache.sis.filter.UnaryFunction<R,Object>

org.apache.sis.filter.UnaryFunction.IsNull<R>

Type Parameters:

R - the type of resources used as inputs.

All Implemented Interfaces:

Serializable, Predicate<R>, Filter<R>, Optimization.OnFilter<R>

Enclosing class:

UnaryFunction<R,V>

static final class UnaryFunction.IsNull<R>
extends UnaryFunction<R,Object>
implements Filter<R>, Optimization.OnFilter<R>

Filter operator that checks if an expression's value is null. A null is equivalent to no value present. The value 0 is a valid value and is not considered null.

Nested Class Summary

Nested classes/interfaces inherited from class org.apache.sis.filter.UnaryFunction

UnaryFunction.IsNil<R>, UnaryFunction.IsNull<R>

Field Summary

Fields

Modifier and Type	Field	Description
private static final long	serialVersionUID	For cross-version compatibility.

Fields inherited from class org.apache.sis.filter.UnaryFunction

expression

Constructor Summary

Constructors

Constructor	Description
IsNull(Expression<? super R,?> expression)	Creates a new operator.

Method Summary

Modifier and Type	Method	Description
ComparisonOperatorName	getOperatorType()	Returns the nature of the operator.
Filter<R>	recreate(Expression<? super R,?>[] effective)	Creates a new filter of the same type but different parameters.
protected char	symbol()	Identification of the operation.
boolean	test(R object)	Evaluate this filter on the given object.

Methods inherited from class org.apache.sis.filter.UnaryFunction

getChildren, getExpressions, getParameters

Methods inherited from class org.apache.sis.internal.filter.Node

createName, createType, equals, getGeometryLibrary, hashCode, toGeometryWrapper, toString, unwrap, warning

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.sis.filter.Filter

getExpressions

Methods inherited from interface org.apache.sis.filter.Optimization.OnFilter

and, negate, optimize, or

Field Details

serialVersionUID

private static final long serialVersionUID

For cross-version compatibility.

See Also:

• Constant Field Values

Constructor Details

IsNull

IsNull(Expression<? super R,?> expression)

Creates a new operator.

Method Details

getOperatorType

public ComparisonOperatorName getOperatorType()

Description copied from interface: Filter

Returns the nature of the operator.

Specified by:

getOperatorType in interface Filter<R>

Returns:

the nature of this operator.

recreate

public Filter<R> recreate(Expression<? super R,?>[] effective)

Creates a new filter of the same type but different parameters.

Specified by:

recreate in interface Optimization.OnFilter<R>

Parameters:

effective - the expressions to use as a replacement of this filter expressions.

Returns:

the new filter, or this if unsupported.

symbol

protected char symbol()

Identification of the operation.

Overrides:

symbol in class Node

Returns:

the mathematical symbol, or 0 if none.

test

public boolean test(R object)

Evaluate this filter on the given object.

Specified by:

test in interface Filter<R>

Specified by:

test in interface Predicate<R>

Parameters:

object - the object (often a Feature instance) to evaluate.

Returns:

true if the test(s) are passed for the provided object.