BaseFeatureCollection (Geotools modules 21.0 API)

Object
- BaseFeatureCollection<T,F>

All Implemented Interfaces:

FeatureCollection<T,F>

Direct Known Subclasses:

BaseSimpleFeatureCollection, ProcessingCollection, WFSContentComplexFeatureCollection
```
public abstract class BaseFeatureCollection<T extends FeatureType,F extends Feature>
extends Object
implements FeatureCollection<T,F>
```
Implement a feature collection just based on provision of a FeatureIterator.
This implementation asks you to implement:
- features()
- This is the direct decentent of the origional AbstractFeatureCollection and represents the easiest way to package your content as a FeatureCollection.
  As this class provides no optimization, it is strongly recommended that you implement the following methods (which require a whole collection traversal):
  - size()
  - {@link #getBounds()
Author:

Jody Garnett (LISAsoft)

Field Summary

Fields
Modifier and Type Field and Description

protected String id
id used when serialized to gml

protected T schema

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

Constructor Summary

Constructors
Modifier	Constructor and Description
`protected`	`BaseFeatureCollection()`
`protected`	`BaseFeatureCollection(T schema)`
`protected`	`BaseFeatureCollection(T schema, String id)`

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`	`contains(Object o)` Returns `true` if this collection contains the specified element.
`boolean`	`containsAll(Collection<?> c)` Returns `true` if this collection contains all of the elements in the specified collection.
`abstract FeatureIterator<F>`	`features()` Subclasses required to implement this method to traverse FeatureCollection contents.
`ReferencedEnvelope`	`getBounds()` Full collection traversal to obtain bounds of FeatureCollection.
`String`	`getID()` ID used when serializing to GML
`T`	`getSchema()` The schema for the child feature members of this collection.
`boolean`	`isEmpty()` Returns `true` if this feature collection contains no features.
`int`	`size()` Returns the number of elements in this collection.
`FeatureCollection<T,F>`	`sort(SortBy order)` Obtained sorted contents, only implemented for SimpleFeature at present.
`FeatureCollection<T,F>`	`subCollection(Filter filter)` Convenience implementation that just wraps this collection into a `FilteringFeatureCollection`.
`Object[]`	`toArray()` Array of all the elements.
`<O> O[]`	`toArray(O[] a)`

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

- Field Detail
  - id
```
protected String id
```
    id used when serialized to gml
  - schema
```
protected T extends FeatureType schema
```
- Constructor Detail
  - BaseFeatureCollection
```
protected BaseFeatureCollection()
```
  - BaseFeatureCollection
```
protected BaseFeatureCollection(T schema)
```
  - BaseFeatureCollection
```
protected BaseFeatureCollection(T schema,
                                String id)
```
- Method Detail
  - getID
```
public String getID()
```
    Description copied from interface: FeatureCollection
    
    ID used when serializing to GML
    
    Specified by:
    
    getID in interface FeatureCollection<T extends FeatureType,F extends Feature>
  - 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
  - features
```
public abstract FeatureIterator<F> features()
```
    Subclasses required to implement this method to traverse FeatureCollection contents.
    Note that FeatureIterator#close() is available to clean up after any resource use required during traversal.
    
    Specified by:
    
    features in interface FeatureCollection<T extends FeatureType,F extends Feature>
    
    Returns:
    
    A FeatureIterator.
  - 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<T extends FeatureType,F extends Feature>
    
    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)
  - 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<T extends FeatureType,F extends Feature>
    
    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:
    
    contains(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 elements.
  - toArray
```
public Object[] toArray()
```
    Array of all the elements.
    
    Specified by:
    
    toArray in interface FeatureCollection<T extends FeatureType,F extends Feature>
    
    Returns:
    
    an array containing all of the elements in this collection.
    
    See Also:
    
    Collection.toArray()
  - toArray
```
public <O> O[] toArray(O[] a)
```
    Specified by:
    
    toArray in interface FeatureCollection<T extends FeatureType,F extends Feature>
    
    See Also:
    
    Collection.toArray(Object[])
  - 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
  - subCollection
```
public FeatureCollection<T,F> subCollection(Filter filter)
```
    Convenience implementation that just wraps this collection into a FilteringFeatureCollection. Subclasses might want to override this in case the filter can be cascaded to their data sources.
    
    Specified by:
    
    subCollection in interface FeatureCollection<T extends FeatureType,F extends Feature>
    
    Parameters:
    
    filter -
    
    Returns:
    
    See Also:
    
    FeatureList
  - sort
```
public FeatureCollection<T,F> sort(SortBy order)
```
    Obtained sorted contents, only implemented for SimpleFeature at present.
    This method only supports SimpleFeature at present, consider 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
  - size
```
public int size()
```
    Returns the number of elements in this collection.
    
    Specified by:
    
    size in interface FeatureCollection<T extends FeatureType,F extends Feature>
    
    Returns:
    
    Number of items, or Interger.MAX_VALUE
    
    See Also:
    
    Collection.size()
  - getBounds
```
public ReferencedEnvelope getBounds()
```
    Full collection traversal to obtain bounds of FeatureCollection. Subclasees are strong encouraged to override this expensive method (even if just to implement caching).
    
    Specified by:
    
    getBounds in interface FeatureCollection<T extends FeatureType,F extends Feature>
    
    Returns:
    
    An Envelope containing the total bounds of this collection.

Class BaseFeatureCollection<T extends FeatureType,F extends Feature>

Field Summary

Constructor Summary

Method Summary

Methods inherited from class Object

Field Detail

id

schema

Constructor Detail

BaseFeatureCollection

BaseFeatureCollection

BaseFeatureCollection

Method Detail

getID

getSchema

features

contains

containsAll

isEmpty

toArray

toArray

accepts

subCollection

sort

size

getBounds