Package org.geotools.feature.collection

Class DecoratingFeatureCollection<T extends FeatureType,​F extends Feature>

  • All Implemented Interfaces:
    FeatureCollection<T,​F>
    Direct Known Subclasses:
    FilteringFeatureCollection, MaxFeaturesFeatureCollection
    public class DecoratingFeatureCollection<T extends FeatureType,​F extends Feature>
extends Object
implements FeatureCollection<T,​F>
    A FeatureCollection which completely delegates to another FeatureCollection.

    This class should be subclasses by classes which must somehow decorate another SimpleFeatureCollection and override the relevant methods.

    Since:
    2.5
    Author:
    Justin Deoliveira, The Open Planning Project, jdeolive@openplans.org

    • Constructor Detail

      • DecoratingFeatureCollection

        protected DecoratingFeatureCollection​(FeatureCollection<T,​F> delegate)

    • Method Detail

      • 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<T extends FeatureType,​F extends Feature>
        Parameters:
        visitor - Closure applied to each feature in turn.
        progress - Used to report progress, may be used to interrupt the operation
        Throws:
        IOException

      • canDelegate

        protected boolean canDelegate​(FeatureVisitor visitor)
        Methods for subclass to override in order to determine if the supplied visitor can be passed to the delegate collection.

        The default is false and the visitor receives the decoraeted features.

      • features

        public FeatureIterator<F> features()
        Description copied from interface: FeatureCollection
        Obtain a FeatureIterator of the Features within this FeatureCollection.

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

        Example use: 

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

        GML Note: The contents of this iterator are considered to be defined by featureMember tags (and/or the single allowed FeatureMembers tag). Please see getFeatureType for more details.

        Specified by:
        features in interface FeatureCollection<T extends FeatureType,​F extends Feature>
        Returns:
        A FeatureIterator.

      • 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>
        Returns:
        FeatureType describing the "common" schema to all child features of this collection

      • hashCode

        public int hashCode()
        Overrides:
        hashCode in class Object

      • isEmpty

        public boolean isEmpty()
        Description copied from interface: FeatureCollection
        Returns true if this feature collection contains no features.
        Specified by:
        isEmpty in interface FeatureCollection<T extends FeatureType,​F extends Feature>
        Returns:
        true if this collection contains no features

      • sort

        public FeatureCollection<T,​F> 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<T extends FeatureType,​F extends Feature>
        Parameters:
        order - Sort order
        Returns:
        FeatureCollection sorted in the indicated order

      • subCollection

        public FeatureCollection<T,​F> 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<T extends FeatureType,​F extends Feature>
        Returns:
        SimpleFeatureCollection identified as subset.
        See Also:
        FeatureList