org.geotools.data.view

Class DefaultView

Object

DefaultView

All Implemented Interfaces:

FeatureSource<SimpleFeatureType,SimpleFeature>, SimpleFeatureSource

public class DefaultView
extends Object
implements SimpleFeatureSource

Wrapper for SimpleFeatureSource constrained by a Query.

Support SimpleFeatureSource decorator that takes care of mapping a Query & SimpleFeatureSource with the schema and definition query configured for it.

Because GeoServer requires that attributes always be returned in the same order we need a way to smoothly inforce this. Could we use this class to do so?

WARNING: this class is a placeholder for ideas right now - it may not always impement FeatureSource.

Author:

Gabriel Rold�n

Field Summary

Fields

Modifier and Type	Field and Description
protected SimpleFeatureSource	source SimpleFeatureSource being served up

Constructor Summary

Constructors

Constructor and Description
DefaultView(SimpleFeatureSource source, Query query) Creates a new GeoServerFeatureSource object.

Method Summary

Modifier and Type	Method and Description
void	addFeatureListener(FeatureListener listener) Implement addFeatureListener.
static SimpleFeatureSource	create(SimpleFeatureSource source, Query query) Factory that make the correct decorator for the provided featureSource.
ReferencedEnvelope	getBounds() Retrieves the total extent of this FeatureSource.
ReferencedEnvelope	getBounds(Query query) Retrive the extent of the Query.
int	getCount(Query query) Adjust query and forward to source.
DataStore	getDataStore() Implement getDataStore.
SimpleFeatureCollection	getFeatures() Implement getFeatures.
SimpleFeatureCollection	getFeatures(Filter filter) Implement getFeatures.
SimpleFeatureCollection	getFeatures(Query query) Implement getFeatures.
ResourceInfo	getInfo() Returns information describing this FeatureSource which may include title, description and spatial parameters.
Name	getName() Returns the name of the features (strictly, the name of the AttributeDescriptor for the features) accessible through this FeatureSource.
QueryCapabilities	getQueryCapabilities() Enquire what what query capabilities this FeatureSource natively supports.
SimpleFeatureType	getSchema() Implement getSchema.
Set	getSupportedHints() Returns the set of hints that this FeatureSource supports via Query requests.
protected Filter	makeDefinitionFilter(Filter filter) If a definition query has been configured for the FeatureTypeInfo, makes and return a new Filter that contains both the query's filter and the layer's definition one, by logic AND'ing them.
protected Query	makeDefinitionQuery(Query query) Takes a query and adapts it to match re definitionQuery filter configured for a feature type.
void	removeFeatureListener(FeatureListener listener) Implement removeFeatureListener.

Methods inherited from class Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

source

protected SimpleFeatureSource source

SimpleFeatureSource being served up

Constructor Detail

DefaultView

public DefaultView(SimpleFeatureSource source,
                   Query query)
            throws SchemaException

Creates a new GeoServerFeatureSource object.

Grabs the following from query:

• typeName - only used if client does not supply
• cs - only used if client does not supply
• csForce - only used if client does not supply
• filter - combined with client filter
• propertyNames - combined with client filter (indicate property names that *must* be included)

Schema is generated based on this information.

Parameters:

source - a FeatureSource

query - Filter used to limit results

Throws:

SchemaException

Method Detail

getName

public Name getName()

Description copied from interface: FeatureSource

Returns the name of the features (strictly, the name of the AttributeDescriptor for the features) accessible through this FeatureSource.

The value returned by this method can be different to that returned by featureSource.getSchema().getType().getName(). This is because there is a distinction between the name applied to features and the name of a feature type. When working with SimpleFeature and SimpleFeatureType, for example with a shapefile data source, it is common practice for feature and feature type names to be the same. However, this is not the case more generally. For instance, a database can contain two tables with the same structure. The feature name will refer to the table while the feature type name refers to the schema (table structure).

Specified by:

getName in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Returns:

the name of the features accessible through this FeatureSource

Since:

2.5

See Also:

FeatureSource.getName()

create

public static SimpleFeatureSource create(SimpleFeatureSource source,
                                         Query query)
                                  throws SchemaException

Factory that make the correct decorator for the provided featureSource.

This factory method is public and will be used to create all required subclasses. By comparison the constructors for this class have package visibiliy. TODO: revisit this - I am not sure I want write access to views (especially if they do reprojection).

Throws:

SchemaException

makeDefinitionQuery

protected Query makeDefinitionQuery(Query query)
                             throws IOException

Takes a query and adapts it to match re definitionQuery filter configured for a feature type. It won't handle coordinate system changes

Grabs the following from query:

• typeName - only used if client does not supply
• filter - combined with client filter
• propertyNames - combined with client filter (indicate property names that *must* be included)

Parameters:

query - Query against this DataStore

Returns:

Query restricted to the limits of definitionQuery

Throws:

IOException - See DataSourceException

DataSourceException - If query could not meet the restrictions of definitionQuery

makeDefinitionFilter

protected Filter makeDefinitionFilter(Filter filter)
                               throws DataSourceException

If a definition query has been configured for the FeatureTypeInfo, makes and return a new Filter that contains both the query's filter and the layer's definition one, by logic AND'ing them.

Parameters:

filter - Origional user supplied Filter

Returns:

Filter adjusted to the limitations of definitionQuery

Throws:

DataSourceException - If the filter could not meet the limitations of definitionQuery

getDataStore

public DataStore getDataStore()

Implement getDataStore.

Description ...

Specified by:

getDataStore in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Returns:

@see org.geotools.data.FeatureSource#getDataStore()

addFeatureListener

public void addFeatureListener(FeatureListener listener)

Implement addFeatureListener.

Description ...

Specified by:

addFeatureListener in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Parameters:

listener - the new listener

See Also:

FeatureSource.addFeatureListener(org.geotools.data.FeatureListener)

removeFeatureListener

public void removeFeatureListener(FeatureListener listener)

Implement removeFeatureListener.

Description ...

Specified by:

removeFeatureListener in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Parameters:

listener - the listener to remove

See Also:

FeatureSource.removeFeatureListener(org.geotools.data.FeatureListener)

getFeatures

public SimpleFeatureCollection getFeatures(Query query)
                                    throws IOException

Implement getFeatures.

Description ...

Specified by:

getFeatures in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Specified by:

getFeatures in interface SimpleFeatureSource

Parameters:

query - DataAccess query for requested information, such as typeName, maxFeatures and filter.

Returns:

features retrieved by the Query

Throws:

IOException - if the underlying data source cannot be accessed.

See Also:

FeatureSource.getFeatures(org.geotools.data.Query)

getFeatures

public SimpleFeatureCollection getFeatures(Filter filter)
                                    throws IOException

Implement getFeatures.

Description ...

Specified by:

getFeatures in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Specified by:

getFeatures in interface SimpleFeatureSource

Parameters:

filter - the filter to select features; must not be null (use Filter.INCLUDE instead)

Returns:

features retrieved by the Filter

Throws:

IOException - if the underlying data source cannot be accessed.

See Also:

Filter

getFeatures

public SimpleFeatureCollection getFeatures()
                                    throws IOException

Implement getFeatures.

Description ...

Specified by:

getFeatures in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Specified by:

getFeatures in interface SimpleFeatureSource

Returns:

features retrieved by the Query

Throws:

IOException - if the underlying data source cannot be accessed.

See Also:

FeatureSource.getFeatures()

getSchema

public SimpleFeatureType getSchema()

Implement getSchema.

Description ...

Specified by:

getSchema in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Returns:

@see org.geotools.data.FeatureSource#getSchema()

getInfo

public ResourceInfo getInfo()

Description copied from interface: FeatureSource

Returns information describing this FeatureSource which may include title, description and spatial parameters. Note that in the returned ResourceInfo object, the distinction between feature name and schema (feature type) name applies as discussed for FeatureSource.getName().

Specified by:

getInfo in interface FeatureSource<SimpleFeatureType,SimpleFeature>

getBounds

public ReferencedEnvelope getBounds()
                             throws IOException

Retrieves the total extent of this FeatureSource.

Please note this extent will reflect the provided definitionQuery.

Specified by:

getBounds in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Returns:

Extent of this FeatureSource, or null if no optimizations exist.

Throws:

IOException - If bounds of definitionQuery

getBounds

public ReferencedEnvelope getBounds(Query query)
                             throws IOException

Retrive the extent of the Query.

This method provides access to an optimized getBounds opperation. If no optimized opperation is available null will be returned.

You may still make use of getFeatures( Query ).getCount() which will return the correct answer (even if it has to itterate through all the results to do so.

Specified by:

getBounds in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Parameters:

query - User's query

Returns:

Extend of Query or null if no optimization is available

Throws:

IOException - If a problem is encountered with source

getCount

public int getCount(Query query)

Adjust query and forward to source.

This method provides access to an optimized getCount opperation. If no optimized opperation is available -1 will be returned.

You may still make use of getFeatures( Query ).getCount() which will return the correct answer (even if it has to itterate through all the results to do so).

Specified by:

getCount in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Parameters:

query - User's query.

Returns:

Number of Features for Query, or -1 if no optimization is available.

getSupportedHints

public Set getSupportedHints()

Description copied from interface: FeatureSource

Returns the set of hints that this FeatureSource supports via Query requests.

Note: the existence of a specific hint does not guarantee that it will always be honored by the implementing class.

Specified by:

getSupportedHints in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Returns:

a set of RenderingHints#Key objects; may be empty but never null

See Also:

Hints.FEATURE_DETACHED, Hints.JTS_GEOMETRY_FACTORY, Hints.JTS_COORDINATE_SEQUENCE_FACTORY, Hints.JTS_PRECISION_MODEL, Hints.JTS_SRID, Hints.GEOMETRY_DISTANCE, Hints.FEATURE_2D

getQueryCapabilities

public QueryCapabilities getQueryCapabilities()

Description copied from interface: FeatureSource

Enquire what what query capabilities this FeatureSource natively supports. For example, whether queries can return sorted results.

Specified by:

getQueryCapabilities in interface FeatureSource<SimpleFeatureType,SimpleFeature>

Returns:

the native query capabilities of this FeatureSource