Package org.geotools.data.collection

Class 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 Detail

      • LOGGER

        protected static Logger LOGGER

      • id

        protected String id
        id used when serialized to gml

    • 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
        memberType - optional, may be null

    • Method Detail

      • 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:
        feature - element whose presence in this collection is to be ensured.
        Returns:
        true if this collection changed as a result of the call

      • 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)

      • 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)

      • 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

      • 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)

      • 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 <O> O[] toArray​(O[] 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​(Iterator close)

      • 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 FeatureCollection<SimpleFeatureType,​SimpleFeature>
        Specified by:
        subCollection in interface SimpleFeatureCollection
        Parameters:
        filter - Filter used to determine sub collection.
        Returns:
        SimpleFeatureCollection identified as subset.
        Since:
        GeoTools 2.2, Filter 1.1
        See Also:
        FeatureList

      • purge

        public void purge()

      • 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