org.geotools.data.collection

Class TreeSetFeatureCollection

Object

TreeSetFeatureCollection

All Implemented Interfaces:

SimpleFeatureCollection, FeatureCollection<SimpleFeatureType,SimpleFeature>

public class TreeSetFeatureCollection
extends Object
implements SimpleFeatureCollection

Origional implementation of FeatureCollection using a TreeMap for internal storage.

The features are maintained in an internal TreeMap resuling in a collection that is sorted by feature id mimicking the contents of a shapefile.

This implementation of FeatureCollection is painfully correct.

• To better mimic an actual data file each feature that is returned is a copy
• The pain comes if you were expecting performance - the overhead associated with copying is significant
• Since a TreeSet (and not a spatial index) is used to store contents their this feature collection does not support fast spatial operations.

With this in mind this implementation is recommended for being careful or you are encountering problems between threads when debugging. It is excellent for its intended purpose of test cases.

Author:

Ian Schneider

Field Summary

Fields

Modifier and Type	Field and Description
protected String	id id used when serialized to gml
protected static Logger	LOGGER
protected SimpleFeatureType	schema FeatureType of contents.

Constructor Summary

Constructors

Constructor and Description
TreeSetFeatureCollection() FeatureCollection schema will be defined by the first added feature.
TreeSetFeatureCollection(FeatureCollection<SimpleFeatureType,SimpleFeature> collection) This constructor should not be used by client code.
TreeSetFeatureCollection(String id, SimpleFeatureType memberType) This constructor should not be used by client code.

Method Summary

Modifier and Type	Method and Description
void	accepts(FeatureVisitor visitor, ProgressListener progress) Visit the contents of a feature collection.
boolean	add(SimpleFeature feature) Ensures that this collection contains the specified element (optional operation).
protected boolean	add(SimpleFeature feature, boolean fire) Deprecated.
boolean	addAll(Collection collection) Adds all of the elements in the specified collection to this collection (optional operation).
boolean	addAll(FeatureCollection<?,?> collection)
void	clear() Removes all of the elements from this collection (optional operation).
void	close(FeatureIterator<SimpleFeature> close)
void	close(Iterator close)
SimpleFeatureCollection	collection()
boolean	contains(Object o) Returns true if this collection contains the specified element.
boolean	containsAll(Collection collection) Test for collection membership.
SimpleFeatureIterator	features() Gets a SimpleFeatureIterator of this feature collection.
Set<String>	fids() Optimization time ... grab the fid set so other can quickly test membership during removeAll/retainAll implementations.
ReferencedEnvelope	getBounds() Gets the bounding box for the features in this feature collection.
int	getCount()
String	getID() ID used when serializing to GML
SimpleFeatureType	getSchema() The schema for the child feature members of this collection.
boolean	isEmpty() Returns true if this collection contains no elements.
Iterator<SimpleFeature>	iterator() Returns an iterator over the elements in this collection.
void	purge()
FeatureReader<SimpleFeatureType,SimpleFeature>	reader()
boolean	remove(Object o) Removes a single instance of the specified element from this collection, if it is present (optional operation).
boolean	removeAll(Collection collection) Removes all this collection's elements that are also contained in the specified collection (optional operation).
boolean	retainAll(Collection collection) Retains only the elements in this collection that are contained in the specified collection (optional operation).
int	size() Returns the number of elements in this collection.
SimpleFeatureCollection	sort(SortBy order) Obtained sorted contents.
SimpleFeatureCollection	subCollection(Filter filter) Will return an optimized subCollection based on access to the origional MemoryFeatureCollection.
Object[]	toArray() Returns an array containing all of the elements in this collection.
Object[]	toArray(Object[] a) Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array.

Methods inherited from class Object

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

Field Detail

LOGGER

protected static Logger LOGGER

id

protected String id

id used when serialized to gml

schema

protected SimpleFeatureType schema

FeatureType of contents.

Constructor Detail

TreeSetFeatureCollection

public TreeSetFeatureCollection()

FeatureCollection schema will be defined by the first added feature.

TreeSetFeatureCollection

public TreeSetFeatureCollection(FeatureCollection<SimpleFeatureType,SimpleFeature> collection)

This constructor should not be used by client code.

Parameters:

collection - SimpleFeatureCollection to copy into memory

TreeSetFeatureCollection

public TreeSetFeatureCollection(String id,
                                SimpleFeatureType memberType)

This constructor should not be used by client code.

Opportunistic reuse is encouraged, but only for the purposes of testing or other specialized uses. Normal creation should occur through org.geotools.core.FeatureCollections.newCollection() allowing applications to customize any generated collections.

Parameters:

id - may be null ... feature id

featureType - optional, may be null

Method Detail

getBounds

public ReferencedEnvelope getBounds()

Gets the bounding box for the features in this feature collection.

Specified by:

getBounds in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Returns:

the envelope of the geometries contained by this feature collection.

add

public boolean add(SimpleFeature feature)

Ensures that this collection contains the specified element (optional operation). Returns true if this collection changed as a result of the call. (Returns false if this collection does not permit duplicates and already contains the specified element.)

Collections that support this operation may place limitations on what elements may be added to this collection. In particular, some collections will refuse to add null elements, and others will impose restrictions on the type of elements that may be added. Collection classes should clearly specify in their documentation any restrictions on what elements may be added.

If a collection refuses to add a particular element for any reason other than that it already contains the element, it must throw an exception (rather than returning false ). This preserves the invariant that a collection always contains the specified element after this call returns.

Parameters:

o - element whose presence in this collection is to be ensured.

Returns:

true if this collection changed as a result of the call

add

@Deprecated
protected boolean add(SimpleFeature feature,
                                  boolean fire)

Deprecated.

addAll

public boolean addAll(Collection collection)

Adds all of the elements in the specified collection to this collection (optional operation). The behavior of this operation is undefined if the specified collection is modified while the operation is in progress. (This implies that the behavior of this call is undefined if the specified collection is this collection, and this collection is nonempty.)

Parameters:

collection - elements to be inserted into this collection.

Returns:

true if this collection changed as a result of the call

See Also:

#add(Object)

addAll

public boolean addAll(FeatureCollection<?,?> collection)

clear

public void clear()

Removes all of the elements from this collection (optional operation). This collection will be empty after this method returns unless it throws an exception.

contains

public boolean contains(Object o)

Returns true if this collection contains the specified element. More formally, returns true if and only if this collection contains at least one element e such that (o==null ? e==null : o.equals(e)).

Specified by:

contains in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Parameters:

o - element whose presence in this collection is to be tested.

Returns:

true if this collection contains the specified element

See Also:

Collection.contains(Object)

containsAll

public boolean containsAll(Collection collection)

Test for collection membership.

Specified by:

containsAll in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Parameters:

collection -

Returns:

true if collection is completly covered

See Also:

Collection.containsAll(Collection)

isEmpty

public boolean isEmpty()

Returns true if this collection contains no elements.

Specified by:

isEmpty in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Returns:

true if this collection contains no elements

iterator

public Iterator<SimpleFeature> iterator()

Returns an iterator over the elements in this collection. There are no guarantees concerning the order in which the elements are returned (unless this collection is an instance of some class that provides a guarantee).

Returns:

an Iterator over the elements in this collection

features

public SimpleFeatureIterator features()

Gets a SimpleFeatureIterator of this feature collection. This allows iteration without having to cast.

Specified by:

features in interface SimpleFeatureCollection

Specified by:

features in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Returns:

the SimpleFeatureIterator for this collection.

remove

public boolean remove(Object o)

Removes a single instance of the specified element from this collection, if it is present (optional operation). More formally, removes an element e such that (o==null ? e==null : o.equals(e)), if this collection contains one or more such elements. Returns true if this collection contained the specified element (or equivalently, if this collection changed as a result of the call).

Parameters:

o - element to be removed from this collection, if present.

Returns:

true if this collection changed as a result of the call

removeAll

public boolean removeAll(Collection collection)

Removes all this collection's elements that are also contained in the specified collection (optional operation). After this call returns, this collection will contain no elements in common with the specified collection.

Parameters:

collection - elements to be removed from this collection.

Returns:

true if this collection changed as a result of the call

See Also:

remove(Object), contains(Object)

retainAll

public boolean retainAll(Collection collection)

Retains only the elements in this collection that are contained in the specified collection (optional operation). In other words, removes from this collection all of its elements that are not contained in the specified collection.

Parameters:

collection - elements to be retained in this collection.

Returns:

true if this collection changed as a result of the call

See Also:

remove(Object), contains(Object)

size

public int size()

Returns the number of elements in this collection. If this collection contains more than Integer.MAX_VALUE elements, returns Integer.MAX_VALUE.

Specified by:

size in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Returns:

the number of elements in this collection

See Also:

Collection.size()

toArray

public Object[] toArray()

Returns an array containing all of the elements in this collection. If the collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.

The returned array will be "safe" in that no references to it are maintained by this collection. (In other words, this method must allocate a new array even if this collection is backed by an array). The caller is thus free to modify the returned array.

This method acts as bridge between array-based and collection-based APIs.

Specified by:

toArray in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Returns:

an array containing all of the elements in this collection

See Also:

Collection.toArray()

toArray

public Object[] toArray(Object[] a)

Returns an array containing all of the elements in this collection; the runtime type of the returned array is that of the specified array. If the collection fits in the specified array, it is returned therein. Otherwise, a new array is allocated with the runtime type of the specified array and the size of this collection.

If this collection fits in the specified array with room to spare (i.e., the array has more elements than this collection), the element in the array immediately following the end of the collection is set to null. This is useful in determining the length of this collection only if the caller knows that this collection does not contain any null elements.)

If this collection makes any guarantees as to what order its elements are returned by its iterator, this method must return the elements in the same order.

Like the toArray method, this method acts as bridge between array-based and collection-based APIs. Further, this method allows precise control over the runtime type of the output array, and may, under certain circumstances, be used to save allocation costs

Suppose l is a List known to contain only strings. The following code can be used to dump the list into a newly allocated array of String:

 String[] x = (String[]) v.toArray(new String[0]);
 

Note that toArray(new Object[0]) is identical in function to toArray().

Specified by:

toArray in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Parameters:

a - the array into which the elements of this collection are to be stored, if it is big enough; otherwise, a new array of the same runtime type is allocated for this purpose.

Returns:

an array containing the elements of this collection

See Also:

Collection.toArray(Object[])

close

public void close(FeatureIterator<SimpleFeature> close)

close

public void close(Iterator close)

reader

public FeatureReader<SimpleFeatureType,SimpleFeature> reader()
                                                      throws IOException

Throws:

IOException

getCount

public int getCount()
             throws IOException

Throws:

IOException

collection

public SimpleFeatureCollection collection()
                                   throws IOException

Throws:

IOException

fids

public Set<String> fids()

Optimization time ... grab the fid set so other can quickly test membership during removeAll/retainAll implementations.

Returns:

Set of fids.

accepts

public void accepts(FeatureVisitor visitor,
                    ProgressListener progress)
             throws IOException

Description copied from interface: FeatureCollection

Visit the contents of a feature collection.

The order of traversal is dependent on the FeatureCollection implementation; some collections are able to make efficient use of an internal index in order to quickly visit features located in the same region.

Specified by:

accepts in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Parameters:

visitor - Closure applied to each feature in turn.

progress - Used to report progress, may be used to interrupt the operation

Throws:

IOException

subCollection

public SimpleFeatureCollection subCollection(Filter filter)

Will return an optimized subCollection based on access to the origional MemoryFeatureCollection.

This method is intended in a manner similar to subList, example use: collection.subCollection( myFilter ).clear()

Specified by:

subCollection in interface SimpleFeatureCollection

Specified by:

subCollection in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Parameters:

filter - Filter used to determine sub collection.

Returns:

SimpleFeatureCollection identified as subset.

Since:

GeoTools 2.2, Filter 1.1

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 SimpleFeatureCollection

Specified by:

sort in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

Parameters:

order - Sort order

Returns:

FeatureCollection sorted in the indicated order

purge

public void purge()

getID

public String getID()

Description copied from interface: FeatureCollection

ID used when serializing to GML

Specified by:

getID in interface FeatureCollection<SimpleFeatureType,SimpleFeature>

getSchema

public SimpleFeatureType 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<SimpleFeatureType,SimpleFeature>

Returns:

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