Package org.geotools.feature.collection

Class AdaptorFeatureCollection

Object
AdaptorFeatureCollection
All Implemented Interfaces:
SimpleFeatureCollection, FeatureCollection<SimpleFeatureType,SimpleFeature>
public abstract class AdaptorFeatureCollection extends Object implements SimpleFeatureCollection
Implement a feature collection just based on provision of iterator.

You will need to implement the following methods:

Author:
Jody Garnett (LISAsoft)

  • Field Details

  • Constructor Details

  • Method Details

    • 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.

    • close

      public void close(FeatureIterator<SimpleFeature> close)

    • close

      public void close(SimpleFeatureIterator close)

    • closeIterator

      public void closeIterator(SimpleFeatureIterator close)

    • accepts

      public void accepts(FeatureVisitor visitor, ProgressListener progress) throws IOException
      Accepts a visitor, which then visits each feature in the collection.
      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

    • subList

      public SimpleFeatureCollection subList(Filter filter)

    • 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

    • 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
      Parameters:
      order - Sort order
      Returns:
      FeatureCollection sorted in the indicated order

    • isEmpty

      public boolean isEmpty()
      Description copied from interface: FeatureCollection
      Returns true if this feature collection contains no features.
      Specified by:
      isEmpty in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
      Returns:
      true if this collection contains no elements.

    • 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:

    • toArray

      public Object[] toArray()
      Array of all the elements.
      Specified by:
      toArray in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
      Returns:
      an array containing all of the elements in this collection.
      See Also:

    • toArray

      public <O> O[] toArray(O[] a)
      Specified by:
      toArray in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
      See Also:

    • containsAll

      public boolean containsAll(Collection c)
      Returns true if this collection contains all of the elements in the specified collection.

      Specified by:
      containsAll in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
      Parameters:
      c - collection to be checked for containment in this collection.
      Returns:
      true if this collection contains all of the elements in the specified collection.
      Throws:
      NullPointerException - if the specified collection is null.
      See Also:

    • toString

      public String toString()
      Returns a string representation of this collection.
      Overrides:
      toString in class Object
      Returns:
      a string representation of this collection.

    • iterator

      public final Iterator<SimpleFeature> iterator()
      Please implement!

      Note: If you return a ResourceIterator, the default implemntation of close( Iterator ) will know what to do.

    • size

      public abstract int size()
      Returns the number of elements in this collection.
      Specified by:
      size in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
      Returns:
      Number of items, or Interger.MAX_VALUE
      See Also:

    • close

      public final void close(Iterator<SimpleFeature> close)
      Clean up after any resources assocaited with this iteartor in a manner similar to JDO collections. Example (safe) use: 
      
 Iterator iterator = collection.iterator();
 try {
     for( Iterator i=collection.iterator(); i.hasNext();){
          Feature feature = (Feature) i.hasNext();
          System.out.println( feature.getID() );
     }
 }
 finally {
     collection.close( iterator );
 }

    • openIterator

      protected abstract Iterator<SimpleFeature> openIterator()
      Open an Iterator, we will call close( iterator ).

      Please subclass to provide your own iterator - note iterator() is implemented to call open() and track the results in for later purge().

      Returns:
      Iterator based on resource use

    • closeIterator

      protected abstract void closeIterator(Iterator<SimpleFeature> close)
      Please override to cleanup after your own iterators, and any used resources.

      As an example if the iterator was working off a File then the inputstream should be closed.

      Subclass must call super.close( close ) to allow the list of open iterators to be adjusted.

      Parameters:
      close - Iterator, will not be null

    • 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

    • getBounds

      public ReferencedEnvelope getBounds()
      Subclasses need to override this.
      Specified by:
      getBounds in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
      Returns:
      An Envelope containing the total bounds of this collection.