DataFeatureCollection (Geotools modules 21.0 API)

Object
- DataFeatureCollection

All Implemented Interfaces:

SimpleFeatureCollection, FeatureCollection<SimpleFeatureType,SimpleFeature>

Direct Known Subclasses:

ArcSdeFeatureCollection, CompositeFeatureCollection, DefaultFeatureResults, EmptyFeatureCollection, IndexedFeatureResults
```
public abstract class DataFeatureCollection
extends Object
implements SimpleFeatureCollection
```
A starting point for implementing FeatureCollection's backed onto a FeatureReader.
This implementation requires you to implement the following:
- getSchema() - this should match reader.getSchema()
- reader()
  features() - override one of these two method to access content
- getBounds()
- getCount()
- collection()
  This class will implement the 'extra' methods required by FeatureCollection for you (in simple terms based on the FeatureResults API). Anything that is often customised is available to you as a constructor parameters.
  Enjoy.
Since:

2.1.RC0

Author:

jgarnett

Field Summary

Fields
Modifier and Type Field and Description

protected String id
id used when serialized to gml

protected List listeners
listeners

protected SimpleFeatureType schema

Fields
Modifier and Type	Field and Description
`protected String`	`id` id used when serialized to gml
`protected List`	`listeners` listeners
`protected SimpleFeatureType`	`schema`

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`DataFeatureCollection()` Collection based on a generic collection
`protected`	`DataFeatureCollection(String id)` Collection based on a generic collection
`protected`	`DataFeatureCollection(String id, SimpleFeatureType memberType)` Subclass must think about what consitructors it needs.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`void`	`accepts(FeatureVisitor visitor, ProgressListener progress)` Visit the contents of a feature collection.
`boolean`	`add(SimpleFeature arg0)`
`boolean`	`addAll(Collection collection)` Optimized implementation of addAll that recognizes the use of collections obtained with subCollection( filter ).
`boolean`	`addAll(FeatureCollection resource)`
`void`	`addListener(CollectionListener listener)`
`void`	`clear()`
`void`	`close(FeatureIterator<SimpleFeature> iterator)`
`void`	`close(Iterator<SimpleFeature> close)`
`protected void`	`closeIterator(Iterator<SimpleFeature> close)`
`boolean`	`contains(Object o)`
`boolean`	`containsAll(Collection<?> collection)`
`SimpleFeatureIterator`	`features()` SimpleFeatureIterator is entirely based on iterator().
`protected void`	`fireChange(Collection coll, int type)`
`protected void`	`fireChange(SimpleFeature[] features, int type)` To let listeners know that something has changed.
`protected void`	`fireChange(SimpleFeature feature, int type)`
`abstract ReferencedEnvelope`	`getBounds()` Get the total bounds of this collection which is calculated by doing a union of the bounds of each feature inside of it
`abstract int`	`getCount()`
`String`	`getID()` ID used when serializing to GML
`SimpleFeatureType`	`getSchema()` The schema for the child feature members of this collection.
`boolean`	`isEmpty()` Default implementation based on creating an reader, testing hasNext, and closing.
`Iterator<SimpleFeature>`	`iterator()` Iterator may (or may) not support modification.
`protected Iterator<SimpleFeature>`	`openIterator()` Returns a FeatureWriterIterator, or FeatureReaderIterator over content.
`void`	`purge()`
`FeatureReader<SimpleFeatureType,SimpleFeature>`	`reader()`
`boolean`	`remove(Object arg0)`
`boolean`	`removeAll(Collection arg0)`
`void`	`removeListener(CollectionListener listener)`
`boolean`	`retainAll(Collection arg0)`
`int`	`size()` Default implementation based on getCount() - this may be expensive
`SimpleFeatureCollection`	`sort(SortBy order)` Construct a sorted view of this content.
`SimpleFeatureCollection`	`subCollection(Filter filter)` Will return an optimized subCollection based on access to the origional FeatureSource.
`Object[]`	`toArray()`
`<T> T[]`	`toArray(T[] array)`
`protected FeatureWriter<SimpleFeatureType,SimpleFeature>`	`writer()` Subclass may provide an implementation of this method to indicate that read/write support is provided.

Methods inherited from class Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - listeners
```
protected List listeners
```
    listeners
  - id
```
protected String id
```
    id used when serialized to gml
  - schema
```
protected SimpleFeatureType schema
```
- Constructor Detail
  - DataFeatureCollection
```
protected DataFeatureCollection()
```
    Collection based on a generic collection
  - DataFeatureCollection
```
protected DataFeatureCollection(String id)
```
    Collection based on a generic collection
  - DataFeatureCollection
```
protected DataFeatureCollection(String id,
                                SimpleFeatureType memberType)
```
    Subclass must think about what consitructors it needs.
- Method Detail
  - fireChange
```
protected void fireChange(SimpleFeature[] features,
                          int type)
```
    To let listeners know that something has changed.
  - fireChange
```
protected void fireChange(SimpleFeature feature,
                          int type)
```
  - fireChange
```
protected void fireChange(Collection coll,
                          int type)
```
  - reader
```
public FeatureReader<SimpleFeatureType,SimpleFeature> reader()
                                                      throws IOException
```
    Throws:
    
    IOException
  - getBounds
```
public abstract ReferencedEnvelope getBounds()
```
    Description copied from interface: FeatureCollection
    
    Get the total bounds of this collection which is calculated by doing a union of the bounds of each feature inside of it
    
    Specified by:
    
    getBounds in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    Returns:
    
    An Envelope containing the total bounds of this collection.
  - getCount
```
public abstract int getCount()
                      throws IOException
```
    Throws:
    
    IOException
  - writer
```
protected FeatureWriter<SimpleFeatureType,SimpleFeature> writer()
                                                         throws IOException
```
    Subclass may provide an implementation of this method to indicate that read/write support is provided.
    All operations that attempt to modify the "data" will use this method, allowing them to throw an "UnsupportedOperationException" in the same manner as Collections.unmodifiableCollection(Collection c), or just return null.
    
    Returns:
    
    the writer, or null if write support is not available
    
    Throws:
    
    UnsupportedOperationException - To indicate that write support is not avaiable
    
    IOException
  - features
```
public SimpleFeatureIterator features()
```
    SimpleFeatureIterator is entirely based on iterator().
    So when we implement FeatureCollection.iterator() this will work out of the box.
    
    Specified by:
    
    features in interface SimpleFeatureCollection
    
    Specified by:
    
    features in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    Returns:
    
    A FeatureIterator.
  - iterator
```
public final Iterator<SimpleFeature> iterator()
```
    Iterator may (or may) not support modification.
  - openIterator
```
protected Iterator<SimpleFeature> openIterator()
                                        throws IOException
```
    Returns a FeatureWriterIterator, or FeatureReaderIterator over content.
    If you have a way to tell that you are readonly please subclass with a less hardcore check - this implementations catches a UnsupportedOpperationsException from wrtier()!
    
    Returns:
    
    Iterator, should be closed closeIterator
    
    Throws:
    
    IOException
  - close
```
public final void close(Iterator<SimpleFeature> close)
```
  - closeIterator
```
protected void closeIterator(Iterator<SimpleFeature> close)
                      throws IOException
```
    Throws:
    
    IOException
  - close
```
public void close(FeatureIterator<SimpleFeature> iterator)
```
  - size
```
public int size()
```
    Default implementation based on getCount() - this may be expensive
    
    Specified by:
    
    size in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    See Also:
    
    Collection.size()
  - purge
```
public void purge()
```
  - isEmpty
```
public boolean isEmpty()
```
    Default implementation based on creating an reader, testing hasNext, and closing.
    For once the Collections API does not give us an escape route, we *have* to check the data.
    
    Specified by:
    
    isEmpty in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    Returns:
    
    true if this collection contains no features
  - contains
```
public boolean contains(Object o)
```
    Specified by:
    
    contains in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    See Also:
    
    Collection.contains(Object)
  - toArray
```
public Object[] toArray()
```
    Specified by:
    
    toArray in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    See Also:
    
    Collection.toArray()
  - toArray
```
public <T> T[] toArray(T[] array)
```
    Specified by:
    
    toArray in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    See Also:
    
    Collection.toArray(Object[])
  - add
```
public boolean add(SimpleFeature arg0)
```
  - remove
```
public boolean remove(Object arg0)
```
  - containsAll
```
public boolean containsAll(Collection<?> collection)
```
    Specified by:
    
    containsAll in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    See Also:
    
    Collection.containsAll(Collection)
  - addAll
```
public boolean addAll(Collection collection)
```
    Optimized implementation of addAll that recognizes the use of collections obtained with subCollection( filter ).
    This method is constructed by either:
    - Filter OR
    - Removing an extact match of Filter AND
  - addAll
```
public boolean addAll(FeatureCollection resource)
```
  - removeAll
```
public boolean removeAll(Collection arg0)
```
  - retainAll
```
public boolean retainAll(Collection arg0)
```
  - clear
```
public void clear()
```
  - 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 FeatureSource.
    The subCollection is constructed by using an AND Filter. For the converse of this opperation please see collection.addAll( Collection ), it has been optimized to be aware of these filter based SubCollections.
    This method is intended in a manner similar to subList, example use: collection.subCollection( myFilter ).clear()
    
    Specified by:
    
    subCollection in interface SimpleFeatureCollection
    
    Specified by:
    
    subCollection in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    Parameters:
    
    filter - Filter used to determine sub collection.
    
    Returns:
    
    SimpleFeatureCollection identified as subset.
    
    Since:
    
    GeoTools 2.2, Filter 1.1
    
    See Also:
    
    FeatureList
  - sort
```
public SimpleFeatureCollection sort(SortBy order)
```
    Construct a sorted view of this content.
    Sorts may be combined togther in a stable fashion, in congruence with the Filter 1.1 specification. This method should also be able to handle GeoTools specific sorting through detecting order as a SortBy2 instance.
    
    Specified by:
    
    sort in interface SimpleFeatureCollection
    
    Specified by:
    
    sort in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
    
    Parameters:
    
    order -
    
    Returns:
    
    FeatureList sorted according to provided order
    
    Since:
    
    GeoTools 2.2, Filter 1.1
  - getID
```
public String getID()
```
    Description copied from interface: FeatureCollection
    
    ID used when serializing to GML
    
    Specified by:
    
    getID in interface FeatureCollection<SimpleFeatureType,SimpleFeature>
  - addListener
```
public final void addListener(CollectionListener listener)
                       throws NullPointerException
```
    Throws:
    
    NullPointerException
  - removeListener
```
public final void removeListener(CollectionListener listener)
                          throws NullPointerException
```
    Throws:
    
    NullPointerException
  - 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

Class DataFeatureCollection

Field Summary

Constructor Summary

Method Summary

Methods inherited from class Object

Field Detail

listeners

id

schema

Constructor Detail

DataFeatureCollection

DataFeatureCollection

DataFeatureCollection

Method Detail

fireChange

fireChange

fireChange

reader

getBounds

getCount

writer

features

iterator

openIterator

close

closeIterator

close

size

purge

isEmpty

contains

toArray

toArray

add

remove

containsAll

addAll

addAll

removeAll

retainAll

clear

accepts

subCollection

sort

getID

addListener

removeListener

getSchema