org.geotools.data.wfs.v1_1_0
Class WFSFeatureSource

java.lang.Object
  extended by org.geotools.data.wfs.v1_1_0.WFSFeatureSource
All Implemented Interfaces:
FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>

public class WFSFeatureSource
extends java.lang.Object
implements FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>

Simple implementation of FeatureSource for a WFS 1.1 server.

This implementation is really simple in the sense that it delegates all the hard work to the WFSDataStore provided.

Since:
2.5.x
Version:
$Id: WFSFeatureSource.java 31823 2008-11-11 16:11:49Z groldan $
Author:
Gabriel Roldan (TOPP)

Constructor Summary
WFSFeatureSource(WFS_1_1_0_DataStore dataStore, java.lang.String typeName)
           
 
Method Summary
 void addFeatureListener(FeatureListener listener)
          Adds a listener to the list that's notified each time a change to the FeatureStore occurs.
 ReferencedEnvelope getBounds()
          Gets the bounding box of this datasource.
 ReferencedEnvelope getBounds(Query query)
          Gets the bounding box of the features that would be returned by this query.
 int getCount(Query query)
          Gets the number of the features that would be returned by this query.
 DataStore getDataStore()
          Access to the DataStore implementing this FeatureStore.
 org.geotools.data.wfs.v1_1_0.WFSFeatureCollection getFeatures()
          Loads all features from the datasource into the return FeatureResults.
 org.geotools.data.wfs.v1_1_0.WFSFeatureCollection getFeatures(org.opengis.filter.Filter filter)
          Loads features from the datasource into the returned FeatureResults, based on the passed filter.
 org.geotools.data.wfs.v1_1_0.WFSFeatureCollection getFeatures(Query query)
          Loads features from the datasource into the returned FeatureResults, based on the passed query.
 ResourceInfo getInfo()
          Returns available metadata for this resource
 org.opengis.feature.type.Name getName()
          Returns the qualified name for the Features this FeatureSource serves.
 QueryCapabilities getQueryCapabilities()
          Returns and indication of what query capabilities this FeatureSource supports natively.
 org.opengis.feature.simple.SimpleFeatureType getSchema()
          Retrieves the featureType that features extracted from this datasource will be created with.
 java.util.Set getSupportedHints()
          Returns the set of hints this FeatureSource is able to support.
 void removeFeatureListener(FeatureListener listener)
          Removes a listener from the list that's notified each time a change to the FeatureStore occurs.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

WFSFeatureSource

public WFSFeatureSource(WFS_1_1_0_DataStore dataStore,
                        java.lang.String typeName)
                 throws java.io.IOException
Throws:
java.io.IOException
Method Detail

getName

public org.opengis.feature.type.Name getName()
Description copied from interface: FeatureSource
Returns the qualified name for the Features this FeatureSource serves.

Note this is different from getSchema().getType().getName() (that is, the feature type name), this name specifies the AttributeDescriptor name for the Features served by this source. So, FeatureSoruce.getName() == FeatureSource.getFeatures().next().getAttributeDescriptor().getName().

Though it's a common practice when dealing with SimpleFeatureType and SimpleFeature to assume they're equal. There's no conflict (as per the dynamic typing system the org.opengis.feature package defines) in a Feature and its type sharing the same name, as well as in a GML schema an element declaration and a type definition may be named the same. Yet, the distinction becomes important as we get rid of that assumption and thus allow to reuse a type definition for different FeatureSoruces, decoupling the descriptor (homologous to the Feature element declaration in a GML schema) from its type definition.

So, even if implementors are allowed to delegate to getSchema().getName() if they want to call the fatures and their type the same, client code asking a DataAccess.getFeatureSource(Name) shall use this name to request for a FeatureSource, rather than the type name, as used in pre 2.5 versions of GeoTools. For example, if we have a FeatureSource named Roads and its type is named Roads_Type, the DataAccess shall be queried through Roads, not Roads_Type.

Specified by:
getName in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
the name of the AttributeDescriptor for the Features served by this FeatureSource

getDataStore

public DataStore getDataStore()
Description copied from interface: FeatureSource
Access to the DataStore implementing this FeatureStore.

Specified by:
getDataStore in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
DataStore implementing this FeatureStore
See Also:
FeatureSource.getDataStore()

getSchema

public org.opengis.feature.simple.SimpleFeatureType getSchema()
Description copied from interface: FeatureSource
Retrieves the featureType that features extracted from this datasource will be created with.

The schema returned is the LCD supported by all available Features. In the common case of shapfiles and database table this schema will match that of every feature available. In the degenerate GML case this will simply reflect the gml:AbstractFeatureType.

Specified by:
getSchema in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
the schema of features created by this datasource.
See Also:
FeatureSource.getSchema()

getInfo

public ResourceInfo getInfo()
Returns available metadata for this resource

Specified by:
getInfo in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:

addFeatureListener

public void addFeatureListener(FeatureListener listener)
Description copied from interface: FeatureSource
Adds a listener to the list that's notified each time a change to the FeatureStore occurs.

Specified by:
addFeatureListener in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Parameters:
listener - FeatureListener
See Also:
FeatureSource.addFeatureListener(FeatureListener)

removeFeatureListener

public void removeFeatureListener(FeatureListener listener)
Description copied from interface: FeatureSource
Removes a listener from the list that's notified each time a change to the FeatureStore occurs.

Specified by:
removeFeatureListener in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Parameters:
listener - FeatureListener
See Also:
FeatureSource.removeFeatureListener(FeatureListener)

getBounds

public ReferencedEnvelope getBounds()
                             throws java.io.IOException
Description copied from interface: FeatureSource
Gets the bounding box of this datasource.

With getBounds(Query) this becomes a convenience method for getBounds(Query.ALL), that is the bounds for all features contained here.

If getBounds() returns null due to expense consider using getFeatures().getBounds() as a an alternative.

Specified by:
getBounds in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
The bounding box of the datasource or null if unknown and too expensive for the method to calculate.
Throws:
java.io.IOException - if there are errors getting the bounding box.
See Also:
FeatureSource.getBounds()

getBounds

public ReferencedEnvelope getBounds(Query query)
                             throws java.io.IOException
Description copied from interface: FeatureSource
Gets the bounding box of the features that would be returned by this query.

To retrieve the bounds of the DataSource please use getBounds( Query.ALL ).

This method is needed if we are to stream features to a gml out, since a FeatureCollection must have a boundedBy element.

If getBounds(Query) returns null due to expense consider using getFeatures(Query).getBounds() as a an alternative.

Specified by:
getBounds in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Parameters:
query - Contains the Filter, and optionally MaxFeatures and StartIndex to find the bounds for.
Returns:
The bounding box of the datasource or null if unknown and too expensive for the method to calculate or any errors occur.
Throws:
java.io.IOException - DOCUMENT ME!
See Also:
FeatureSource.getBounds(Query)

getCount

public int getCount(Query query)
             throws java.io.IOException
Description copied from interface: FeatureSource
Gets the number of the features that would be returned by this query.

If getBounds(Query) returns -1 due to expense consider using getFeatures(Query).getCount() as a an alternative.

This method should take into account the Query's maxFeatures and startIndex, if present, in order to consistently return the number of features the query would return.

Specified by:
getCount in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Parameters:
query - Contains the Filter, and optionally MaxFeatures and StartIndex to find the count for.
Returns:
The number of Features provided by the Query or -1 if count is too expensive to calculate or any errors or occur.
Throws:
java.io.IOException - if there are errors getting the count
See Also:
FeatureSource.getCount(Query)

getFeatures

public org.geotools.data.wfs.v1_1_0.WFSFeatureCollection getFeatures(org.opengis.filter.Filter filter)
                                                              throws java.io.IOException
Description copied from interface: FeatureSource
Loads features from the datasource into the returned FeatureResults, based on the passed filter.

Specified by:
getFeatures in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Parameters:
filter - An OpenGIS filter; specifies which features to retrieve. null is not allowed, use Filter.INCLUDE instead.
Returns:
Collection The collection to put the features into.
Throws:
java.io.IOException - For all data source errors.
See Also:
FeatureSource.getFeatures(Filter)

getFeatures

public org.geotools.data.wfs.v1_1_0.WFSFeatureCollection getFeatures()
                                                              throws java.io.IOException
Description copied from interface: FeatureSource
Loads all features from the datasource into the return FeatureResults.

Filter.INCLUDE can also be used to get all features. Calling this function is equivalent to using Query.ALL

Specified by:
getFeatures in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
Collection The collection to put the features into.
Throws:
java.io.IOException - For all data source errors.
See Also:
FeatureSource.getFeatures()

getFeatures

public org.geotools.data.wfs.v1_1_0.WFSFeatureCollection getFeatures(Query query)
                                                              throws java.io.IOException
Description copied from interface: FeatureSource
Loads features from the datasource into the returned FeatureResults, based on the passed query.

Specified by:
getFeatures in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Parameters:
query - a datasource query object. It encapsulates requested information, such as typeName, maxFeatures and filter.
Returns:
Collection The collection to put the features into.
Throws:
java.io.IOException - For all data source errors.
See Also:
FeatureSource.getFeatures(Query)

getSupportedHints

public java.util.Set getSupportedHints()
Description copied from interface: FeatureSource
Returns the set of hints this FeatureSource is able to support.

Hints are to be specified in the Query, for each data access where they may be required.
Depending on the actual value provide by the user, the FeatureSource may decide not to honor the hint.

Specified by:
getSupportedHints in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
a set of RenderingHints#Key objects (eventually empty, never null).
See Also:
FeatureSource.getSupportedHints()

getQueryCapabilities

public QueryCapabilities getQueryCapabilities()
Description copied from interface: FeatureSource
Returns and indication of what query capabilities this FeatureSource supports natively.

Specified by:
getQueryCapabilities in interface FeatureSource<org.opengis.feature.simple.SimpleFeatureType,org.opengis.feature.simple.SimpleFeature>
Returns:
a QueryCapabilities object containing the native query capabilities.


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