Package org.geotools.data.collection

Class ListFeatureCollection

Object

AbstractFeatureCollection

ListFeatureCollection

All Implemented Interfaces:

Iterable<SimpleFeature>, Collection<SimpleFeature>, SimpleFeatureCollection, FeatureCollection<SimpleFeatureType,SimpleFeature>

public class ListFeatureCollection
extends AbstractFeatureCollection
implements Collection<SimpleFeature>

FeatureCollection implementation wrapping around a java.util.List.

This implementation wraps around a java.util.List and is suitable for quickly getting something on screen.

Usage notes:

• This implementation does not use a spatial index, please do not expect spatial operations to be fast.
• FeatureCollections are not allowed to have duplicates

This implementation is intended to quickly wrap up a list of features and get them on screen; as such it respects various hints about the copying of internal content as provided by the renderer.

Author:

Oliver Gottwald, Jody

See Also:

• Hints#FEATURE_DETACHED

Field Summary

Fields

Modifier and Type	Field	Description
protected ReferencedEnvelope	bounds	Cached bounds
protected List<SimpleFeature>	list	wrapped list of features containing the contents

Fields inherited from class AbstractFeatureCollection

id, schema

Constructor Summary

Constructors

Constructor	Description
ListFeatureCollection(SimpleFeatureType schema)	Create a ListFeatureCollection for the provided schema An ArrayList is used internally.
ListFeatureCollection(SimpleFeatureType schema, List<SimpleFeature> list)	Create a ListFeatureCollection around the provided list.
ListFeatureCollection(SimpleFeatureType schema, SimpleFeature... array)	Create a ListFeatureCollection around the provided array.
ListFeatureCollection(SimpleFeatureCollection copy)	Create a ListFeatureCollection around the provided list.

Method Summary

Modifier and Type	Method	Description
boolean	add(SimpleFeature f)
boolean	addAll(Collection<? extends SimpleFeature> c)
protected ReferencedEnvelope	calculateBounds()	Calculate bounds from features
void	clear()
SimpleFeatureIterator	features()	Obtain a SimpleFeatureIterator of the Features within this SimpleFeatureCollection.
ReferencedEnvelope	getBounds()	Subclasses need to override this.
boolean	isEmpty()	Returns true if this feature collection contains no features.
protected Iterator<SimpleFeature>	openIterator()	Factory method used to open an iterator over collection contents for use by AbstractFeatureCollection.iterator() and AbstractFeatureCollection.features().
boolean	remove(Object o)
boolean	removeAll(Collection<?> c)
boolean	retainAll(Collection<?> c)
int	size()	Returns the number of elements in this collection.
SimpleFeatureCollection	sort(SortBy order)	Obtained sorted contents.
SimpleFeatureCollection	subCollection(Filter filter)	SimpleFeatureCollection "view" indicated by provided filter.

Methods inherited from class AbstractFeatureCollection

accepts, contains, containsAll, getID, getSchema, iterator, toArray, toArray

Methods inherited from class Object

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

Methods inherited from interface Collection

contains, containsAll, equals, hashCode, iterator, parallelStream, removeIf, spliterator, stream, toArray, toArray, toArray

Methods inherited from interface Iterable

forEach

Field Details

list

protected List<SimpleFeature> list

wrapped list of features containing the contents

bounds

protected ReferencedEnvelope bounds

Cached bounds

Constructor Details

ListFeatureCollection

public ListFeatureCollection(SimpleFeatureType schema)

Create a ListFeatureCollection for the provided schema An ArrayList is used internally.

ListFeatureCollection

public ListFeatureCollection(SimpleFeatureType schema,
 List<SimpleFeature> list)

Create a ListFeatureCollection around the provided list. The contents of the list should all be of the provided schema for this to make sense. Please keep in mind the feature collection constraints, no two Features in the list should have the same feature id, and you should not insert the same feature more then once.

The provided list is directly used for storage, most feature collection operations just use a simple iterator so there is no performance advantaged to be gained over using an ArrayList vs a LinkedList (other then for the size() method of course).

ListFeatureCollection

public ListFeatureCollection(SimpleFeatureType schema,
 SimpleFeature... array)

Create a ListFeatureCollection around the provided array. The contents of the array should all be of the provided schema for this to make sense. Please keep in mind the feature collection constraints, no two Features in the list should have the same feature id, and you should not insert the same feature more then once.

The provided array is directly used with a CopyOnWriteArrayList for storage.

ListFeatureCollection

public ListFeatureCollection(SimpleFeatureCollection copy)
                      throws IOException

Create a ListFeatureCollection around the provided list. The contents of the list should all be of the provided schema for this to make sense. Please keep in mind the feature collection control, no two Features in the list should have the same feature id, and you should not insert the same feature more then once.

The provided list is directly used for storage, most feature collection operations just use a simple iterator so there is no performance advantaged to be gained over using an ArrayList vs a LinkedList (other then for the size() method of course).

Throws:

IOException

Method Details

size

public int size()

Description copied from class: AbstractFeatureCollection

Returns the number of elements in this collection.

Specified by:

size in interface Collection<SimpleFeature>

Specified by:

size in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Specified by:

size in class AbstractFeatureCollection

Returns:

Number of items, or Interger.MAX_VALUE

See Also:

• Collection.size()

openIterator

protected Iterator<SimpleFeature> openIterator()

Description copied from class: AbstractFeatureCollection

Factory method used to open an iterator over collection contents for use by AbstractFeatureCollection.iterator() and AbstractFeatureCollection.features().

If you return an instance of FeatureIterator some effort is taken to call the FeatureIterator.close() internally, however we cannot offer any assurance that client code using AbstractFeatureCollection.iterator() will perform the same check.

Specified by:

openIterator in class AbstractFeatureCollection

Returns:

Iterator over collection contents

add

public boolean add(SimpleFeature f)

Specified by:

add in interface Collection<SimpleFeature>

clear

public void clear()

Specified by:

clear in interface Collection<SimpleFeature>

features

public SimpleFeatureIterator features()

Description copied from interface: SimpleFeatureCollection

Obtain a SimpleFeatureIterator of the Features within this SimpleFeatureCollection.

The implementation of FeatureIterator must adhere to the rules of fail-fast concurrent modification. In addition (to allow for resource backed collections) the SimpleFeatureIterator.close() method must be called.

Example use:

 SimpleFeatureIterator iterator=collection.features();
 try {
     while( iterator.hasNext()  ){
          SimpleFeature feature = iterator.next();
          System.out.println( feature.getID() );
     }
 }
 finally {
     iterator.close();
 }
 

Specified by:

features in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Specified by:

features in interface SimpleFeatureCollection

Overrides:

features in class AbstractFeatureCollection

Returns:

A FeatureIterator.

getBounds

public ReferencedEnvelope getBounds()

Description copied from class: AbstractFeatureCollection

Subclasses need to override this.

Specified by:

getBounds in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Specified by:

getBounds in class AbstractFeatureCollection

Returns:

An Envelope containing the total bounds of this collection.

calculateBounds

protected ReferencedEnvelope calculateBounds()

Calculate bounds from features

isEmpty

public boolean isEmpty()

Description copied from interface: FeatureCollection

Returns true if this feature collection contains no features.

Specified by:

isEmpty in interface Collection<SimpleFeature>

Specified by:

isEmpty in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Overrides:

isEmpty in class AbstractFeatureCollection

Returns:

true if this collection contains no elements.

subCollection

public SimpleFeatureCollection subCollection(Filter filter)

Description copied from interface: FeatureCollection

SimpleFeatureCollection "view" indicated by provided filter.

The contents of the returned SimpleFeatureCollection are determined by applying the provider Filter to the entire contents of this FeatureCollection. The result is "live" and modifications will be shared.

This method is used cut down on the number of filter based methods required for a useful SimpleFeatureCollection construct. The FeatureCollections returned really should be considered as a temporary "view" used to control the range of a removeAll, or modify operation.

Example Use:

 collection.subCollection( filter ).clear();
 

The above recommended use is agreement with the Collections API precident of List.subList( start, end ).

The results of subCollection:

• are to be considered unordered
• may be an ordered FeatureList if requested when sortBy is indicated

Specified by:

subCollection in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Specified by:

subCollection in interface SimpleFeatureCollection

Overrides:

subCollection in class AbstractFeatureCollection

Returns:

SimpleFeatureCollection identified as subset.

See Also:

• FeatureList

sort

public SimpleFeatureCollection sort(SortBy order)

Description copied from interface: FeatureCollection

Obtained sorted contents.

This method may not be supported by all implementations, consider the use of FeatureSource.features( Query ).

Specified by:

sort in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Specified by:

sort in interface SimpleFeatureCollection

Overrides:

sort in class AbstractFeatureCollection

Parameters:

order - Sort order

Returns:

FeatureCollection sorted in the indicated order

remove

public boolean remove(Object o)

Specified by:

remove in interface Collection<SimpleFeature>

addAll

public boolean addAll(Collection<? extends SimpleFeature> c)

Specified by:

addAll in interface Collection<SimpleFeature>

removeAll

public boolean removeAll(Collection<?> c)

Specified by:

removeAll in interface Collection<SimpleFeature>

retainAll

public boolean retainAll(Collection<?> c)

Specified by:

retainAll in interface Collection<SimpleFeature>