org.opengis.feature

Interface Feature

All Superinterfaces:

Attribute, ComplexAttribute, Property

All Known Subinterfaces:

SimpleFeature

All Known Implementing Classes:

DecoratingFeature, FeatureImpl, JDBCFeatureReader.ResultSetFeature, MongoDBObjectFeature, MongoFeature, PreGeneralizedSimpleFeature, SimpleFeatureImpl

public interface Feature
extends ComplexAttribute

An instance of FeatureType representing a geographic feature composed of geometric and non-geometric properties.

Beyond being a complex attribute, a feature contains the following additional information:

• A default geometry. To be used when drawing when nothing more specific has been provided.
• The bounds of all the geometric attributes of the feature

Since:

GeoAPI 2.2

Author:

Jody Garnett (Refractions Research), Justin Deoliveira (The Open Planning Project)

See Also:

FeatureType

Method Summary

Modifier and Type	Method and Description
BoundingBox	getBounds() The bounds of this Feature, if available.
GeometryAttribute	getDefaultGeometryProperty() The default geometric attribute of the feature.
FeatureId	getIdentifier() A unique identifier for the feature.
FeatureType	getType() Override and type narrow to FeatureType.
void	setDefaultGeometryProperty(GeometryAttribute geometryAttribute) Sets the default geometric attribute of the feature.

Methods inherited from interface ComplexAttribute

getProperties, getProperties, getProperties, getProperty, getProperty, getValue, setValue, validate

Methods inherited from interface Attribute

getDescriptor

Methods inherited from interface Property

getName, getUserData, isNillable, setValue

Method Detail

getType

FeatureType getType()

Override and type narrow to FeatureType.

Specified by:

getType in interface Attribute

Specified by:

getType in interface ComplexAttribute

Specified by:

getType in interface Property

Returns:

The feature type

See Also:

Attribute.getType()

getIdentifier

FeatureId getIdentifier()

A unique identifier for the feature.

getType().isIdentifiable() must return true so this value must not return null.

Generation of the identifier is dependent on the underlying data storage medium. Often this identifier is not persistent. Mediums such shapefiles and database tables have "keys" built in which map naturally to persistent feature identifiers. But other mediums do not have such keys and may have to generate feature identifiers "on-the-fly". This means that client code being able to depend on this value as a persistent entity is dependent on which storage medium or data source is being used.

Specified by:

getIdentifier in interface Attribute

Returns:

The feature identifier, never null.

getBounds

BoundingBox getBounds()

The bounds of this Feature, if available.

This value is derived from any geometric attributes that the feature is composed of.

In the case that the feature has no geometric attributes this method should return an empty bounds, ie, bounds.isEmpty() == true. This method should never return null.

The coordinate reference system of the returned bounds is derived from the geometric attributes which were used to compute the bounds. In the event that the feature contains multiple geometric attributes which have different crs's, the one defined by #getGeometryDescriptor() should take precedence and the others should be reprojected accordingly.

Returns:

the feature bounds, possibly empty.

getDefaultGeometryProperty

GeometryAttribute getDefaultGeometryProperty()

The default geometric attribute of the feature.

This method returns null in the case where no such attribute exists.

Returns:

The default geometry attribute, or null.

setDefaultGeometryProperty

void setDefaultGeometryProperty(GeometryAttribute geometryAttribute)

Sets the default geometric attribute of the feature.

This value must be an attribute which is already defined for the feature. In other words, this method can not be used to add a new attribute to the feature.

Parameters:

geometryAttribute - The new geomtric attribute.

Throws:

IllegalArgumentException - If the specified attribute is not already an attribute of the feature.