Package org.geotools.feature.collection

Class AbstractFeatureCollection

    • Constructor Detail

      • AbstractFeatureCollection

        protected AbstractFeatureCollection​(SimpleFeatureType memberType)

    • Method Detail

      • 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
        Returns:
        A FeatureIterator.

      • openIterator

        protected abstract Iterator<SimpleFeature> openIterator()
        Factory method used to open an iterator over collection contents for use by iterator() and 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 iterator() will perform the same check.

        Returns:
        Iterator over collection contents

      • contains

        public boolean contains​(Object o)
        Returns true if this collection contains the specified element. .

        This implementation iterates over the elements in the collection, checking each element in turn for equality with the specified element.

        Specified by:
        contains in interface FeatureCollection<SimpleFeatureType,​SimpleFeature>
        Parameters:
        o - object to be checked for containment in this collection.
        Returns:
        true if this collection contains the specified element.
        See Also:
        Collection.contains(Object)

      • iterator

        public final Iterator<SimpleFeature> iterator()
        Provides acess to openIterator() used to traverse collection contents.

        You are asked to perform the following check when finished with the iterator: 

         if( e instanceof FeatureIterator ){
    (FeatureIterator)iterator).close();
 }
        Returns:
        Iterator traversing collection contents

      • 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)
        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
        Returns:
        SimpleFeatureCollection identified as subset.
        See Also:
        FeatureList

      • 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