org.geotools.process.vector

Class ProcessingCollection<T extends FeatureType,F extends Feature>

Object

BaseFeatureCollection<T,F>

ProcessingCollection<T,F>

Type Parameters:

T -

F -

All Implemented Interfaces:

FeatureCollection<T,F>

Direct Known Subclasses:

SimpleProcessingCollection

public abstract class ProcessingCollection<T extends FeatureType,F extends Feature>
extends BaseFeatureCollection<T,F>

Abstract base class to ease the implementation of a streaming processing collection, that is, one that tries to compute the results on the fly as the iterator is traversed.

Besides the few methods that the implementor actually needs to override it suggested to consider overriding also the followings to get extra performance gains:

BaseFeatureCollection.subCollection(Filter) BaseFeatureCollection.sort(SortBy)

Author:

Andrea Aime - GeoSolutions

Field Summary

Fields inherited from class BaseFeatureCollection

id, schema

Constructor Summary

Constructors

Constructor and Description
ProcessingCollection()

Method Summary

Modifier and Type	Method and Description
protected abstract T	buildTargetFeatureType() Builds once and for all the target feature type.
abstract FeatureIterator<F>	features() Streams out the output features
abstract ReferencedEnvelope	getBounds() The bounds of features in the output.
T	getSchema() The schema for the child feature members of this collection.
abstract int	size() The number of features in the output.

Methods inherited from class BaseFeatureCollection

accepts, contains, containsAll, getID, isEmpty, sort, subCollection, toArray, toArray

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

ProcessingCollection

public ProcessingCollection()

Method Detail

features

public abstract FeatureIterator<F> features()

Streams out the output features

Specified by:

features in interface FeatureCollection<T extends FeatureType,F extends Feature>

Specified by:

features in class BaseFeatureCollection<T extends FeatureType,F extends Feature>

Returns:

A FeatureIterator.

getBounds

public abstract ReferencedEnvelope getBounds()

The bounds of features in the output. If the bounds are not known in advance once can call the getFeatureBounds() which will build it from the features as they are returned from the feature iterator.

Specified by:

getBounds in interface FeatureCollection<T extends FeatureType,F extends Feature>

Overrides:

getBounds in class BaseFeatureCollection<T extends FeatureType,F extends Feature>

Returns:

An Envelope containing the total bounds of this collection.

buildTargetFeatureType

protected abstract T buildTargetFeatureType()

Builds once and for all the target feature type. The results are available by calling getSchema()

size

public abstract int size()

The number of features in the output. If the size is not known in advance once can call the getFeatureCount() which will count the features as they are returned from the feature iterator.

Specified by:

size in interface FeatureCollection<T extends FeatureType,F extends Feature>

Overrides:

size in class BaseFeatureCollection<T extends FeatureType,F extends Feature>

Returns:

Number of items, or Interger.MAX_VALUE

See Also:

Collection.size()

getSchema

public T getSchema()

Description copied from interface: FeatureCollection

The schema for the child feature members of this collection.

Represents the most general FeatureType in common to all the features in this collection.

• For a collection backed by a shapefiles (or database tables) the FeatureType returned by getSchema() will complete describe each and every child in the collection.
• For mixed content FeatureCollections you will need to check the FeatureType of each Feature as it is retrived from the collection
• The degenerate case returns the "_Feature" FeatureType, where the only thing known is that the contents are Features.

Specified by:

getSchema in interface FeatureCollection<T extends FeatureType,F extends Feature>

Overrides:

getSchema in class BaseFeatureCollection<T extends FeatureType,F extends Feature>

Returns:

FeatureType describing the "common" schema to all child features of this collection