org.opengis.filter.package.html Maven / Gradle / Ivy
package org.opengis.filter
Filters {@linkplain org.opengis.feature.Feature features} according their properties.
A filter expression is a construct used to constraints the property
values of an object type for the purpose of identifying a subset of object instances
to be operated upon in some manner.
The following is adapted from the OpenGIS®
Filter Encoding Implementation Specification:
Comparison operators
A comparison operator is used to form expressions that evaluate
the mathematical comparison between two arguments. If the arguments satisfy the comparison
then the expression {@linkplain org.opengis.filter.Filter#evaluate evaluates} to {@code true}.
Otherwise the expression evaluates to {@code false}.
In addition to the standard set
({@code =},{@code <},{@code >},{@code >=},{@code <=},{@code <>}) of comparison operators,
this package defines the elements {@link org.opengis.filter.PropertyIsLike},
{@link org.opengis.filter.PropertyIsBetween} and {@link org.opengis.filter.PropertyIsNull}.
Logical operators
A logical operator can be used to combine one or more conditional expressions.
The logical operator {@link org.opengis.filter.And} evaluates to {@code true} if all the combined
expressions evaluate to {@code true}. The operator {@link org.opengis.filter.Or} operator evaluates
to {@code true} is any of the combined expressions evaluate to {@code true}. The
{@link org.opengis.filter.Not} operator reverses the logical value of an expression.
The elements {@code And}, {@code Or} and {@code Not} can be used to combine scalar,
spatial and other logical expressions to form more complex compound expressions.
Identity
Identity can be checked using {@link org.opengis.filter.Id}, selected objects
will are matched against a set of {@link org.opengis.filter.identiy.Identifier}.