org.geotools.data.simple

Interface SimpleFeatureCollection

All Superinterfaces:

FeatureCollection<SimpleFeatureType,SimpleFeature>

All Known Subinterfaces:

RandomFeatureAccess, XmlFeatureCollection

All Known Implementing Classes:

AbstractFeatureCollection, AdaptorFeatureCollection, ArcSdeFeatureCollection, BaseSimpleFeatureCollection, CollectionFeatureSource.SubCollection, CompositeFeatureCollection, ContentFeatureCollection, DataFeatureCollection, DecoratingSimpleFeatureCollection, DefaultFeatureCollection, DefaultFeatureResults, EmptyFeatureCollection, FilteringSimpleFeatureCollection, ForceCoordinateSystemFeatureResults, GMLFeatureCollection, IndexedFeatureResults, ListFeatureCollection, MaxSimpleFeatureCollection, MemoryFeatureCollection, PreGeneralizedFeatureCollection, ReprojectFeatureResults, ReprojectingFeatureCollection, ReTypingFeatureCollection, SimpleProcessingCollection, SortedSimpleFeatureCollection, SpatialIndexFeatureCollection, SubFeatureCollection, SubFeatureList, TreeSetFeatureCollection

public interface SimpleFeatureCollection
extends FeatureCollection<SimpleFeatureType,SimpleFeature>

Access to "simple" Feature content where each feature has the same SimpleFeatureType.

Please keep in mind that a SimpleFeatureCollection is similar to a result set; and may not necessarily load everything in to memory. Treat each iterator as a forward only cursor in the JDBC sense; and take care to FeatureIterator.close() after use.

SimpleFeatureIterator close

SimpleFeatureCollection provides streaming access with the following restrictions on use of SimpleFeatureIterator: You must call FeatureIterator.close(). This allows FeatureCollection to clean up any operating system resources used to access information.

Example (safe) use:

 SimpleFeatureIterator iterator = simpleFeatureCollection.features();
 try {
     while( iterator.hasNext() ){
          SimpleFeature feature = iterator.next();
          System.out.println( feature.getID() );
     }
 }
 finally {
     iterator.close();
 }
 

And in Java 7:

 try ( SimpleFeatureIterator iterator = simpleFeatureCollection.features() ){
     while( iterator.hasNext() ){
          SimpleFeature feature = iterator.next();
          System.out.println( feature.getID() );
     }
 }
 

Method Summary

Modifier and Type	Method and Description
SimpleFeatureIterator	features() Obtain a SimpleFeatureIterator of the Features within this SimpleFeatureCollection.
SimpleFeatureCollection	sort(SortBy order) Obtained sorted contents.
SimpleFeatureCollection	subCollection(Filter filter) SimpleFeatureCollection "view" indicated by provided filter.

Methods inherited from interface FeatureCollection

accepts, contains, containsAll, getBounds, getID, getSchema, isEmpty, size, toArray, toArray

Method Detail

features

SimpleFeatureIterator features()

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>

Returns:

A FeatureIterator.

subCollection

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>

Returns:

SimpleFeatureCollection identified as subset.

See Also:

FeatureList

sort

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>

Parameters:

order - Sort order

Returns:

FeatureCollection sorted in the indicated order