Package org.opengis.feature

Defines the structure and content of views of real-world phenomenon. A feature acts as a model of a real world entity. As such it has many similarities to object oriented programming ideas of classes, fields and methods. A FeatureType is similar to a Class in Java and can contain three kinds of properties:

• AttributeType holds information about an attribute (similar to a Field in Java).
• FeatureAssociationRole defines a relationship a feature is involved in (aggregation, composition, etc.).
• Operation describes functionality a feature is able to perform (similar to Method in Java).

Features containing only attributes constrained to the [1 … 1] multiplicity and said simple. Such simple features can also be represented by Record instances.

An important aspect of a Feature is the fact that it is a dynamic data construct defined at runtime. Traditionally the Java programming language represents dynamic data structures using java.util.Map. One could think of a Feature as a Map in which the keys (i.e. the property names) are well defined.

Feature types model is described in the ISO 19109 specification. The following table shows the class hierarchy:

Feature class hierarchy

Types (from ISO 19109)	Instances (GeoAPI specific)
IdentifiedType ├─ FeatureType └─ PropertyType ├─ AttributeType ├─ FeatureAssociationRole └─ Operation	Feature Property ├─ Attribute └─ FeatureAssociation

Since:

3.1

Interface Summary

Interface	Description
Attribute<V>	An instance of an AttributeType containing the value of an attribute in a feature.
AttributeType<V>	Definition of an attribute in a feature type.
DynamicAttribute<V>	An instance of a DynamicAttributeType containing time-dependent values of an attribute.
DynamicAttributeType<V>	Definition of a dynamic attribute in a moving feature type.
Feature	An instance of a FeatureType containing values for a real-world phenomena.
FeatureAssociation	An instance of an FeatureAssociationRole containing the associated feature.
FeatureAssociationRole	Indicates the role played by the association between two features.
FeatureType	Abstraction of a real-world phenomena.
IdentifiedType	Identification and description information inherited by property types and feature types.
Operation	Describes the behaviour of a feature type as a function or a method.
Property	An instance of a PropertyType.
PropertyType	Characteristics that may be associated with a FeatureType.

Exception Summary

Exception	Description
FeatureInstantiationException	Thrown when FeatureType.newInstance() is invoked but the feature can not be instantiated.
FeatureOperationException	Thrown when Operation.apply(…) is invoked but the operation can not complete.
InvalidPropertyValueException	Thrown when an Attribute value or a FeatureAssociation does not met the constraints (other than Java class) specified by its type.
MismatchedFeatureException	Indicates that an operation cannot be completed properly because of a mismatch in the attribute or feature type of operands.
MultiValuedPropertyException	Thrown when Attribute.getValue() or FeatureAssociation.getValue() is invoked on a property containing more than one value.
OutOfTemporalDomainException	Thrown when the temporal position given to a dynamic attribute valuesAt method is outside the period of validity.
PropertyNotFoundException	Thrown when a property requested by its name is not found in a Feature or FeatureType.