org.deegree.io.datastore
Class PropertyPathResolver

java.lang.Object
  org.deegree.io.datastore.PropertyPathResolver

public class PropertyPathResolver
extends Object

Helper class that resolves PropertyPath instances (e.g. PropertyName elements in GetFeature) against the property structure of MappedFeatureTypes.

Version:

$Revision: 20808 $, $Date: 2009-11-16 14:03:13 +0100 (Mo, 16. Nov 2009) $

Author:

Markus Schneider , last edited by: $Author: mschneider $

Constructor Summary

PropertyPathResolver()

Method Summary

static Map<MappedPropertyType,Collection<PropertyPath>>	determineFetchProperties(MappedFeatureType ft, String alias, PropertyPath[] requestedPaths) Determines the properties of the given feature type that have to be fetched based on the requested property paths.
static PropertyPath[]	determineSubPropertyPaths(MappedFeatureType featureType, Collection<PropertyPath> propertyPaths) Determines the sub property paths that are needed to fetch the given property paths for the also given property.
static PropertyPath	normalizePropertyPath(MappedFeatureType ft, String alias, PropertyPath path) Ensures that the requested property begins with a "feature type step" (this may also be an alias).
static List<PropertyPath>[]	normalizePropertyPaths(MappedFeatureType[] fts, String[] ftAliases, PropertyPath[] paths) Ensures that all requested properties begin with a feature type (or alias) step.
static PropertyPath[]	normalizePropertyPaths(MappedFeatureType ft, String alias, PropertyPath[] paths) Ensures that all requested properties begin with a feature type step or an alias.

Methods inherited from class java.lang.Object

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

Constructor Detail

PropertyPathResolver

public PropertyPathResolver()

Method Detail

normalizePropertyPath

public static PropertyPath normalizePropertyPath(MappedFeatureType ft,
                                                 String alias,
                                                 PropertyPath path)

Ensures that the requested property begins with a "feature type step" (this may also be an alias).

This is necessary, as section 7.4.2 of the Web Feature Implementation Specification 1.1.0 states:

The first step of a relative location path may correspond to the root element of the feature property being referenced or to the root element of the feature type with the next step corresponding to the root element of the feature property being referenced.

Parameters:

ft - featureType that the requested properties refer to

alias - alias for the feature type (may be null)

path - requested property

Returns:

normalized path, i.e. it begins with a feature type step

normalizePropertyPaths

public static PropertyPath[] normalizePropertyPaths(MappedFeatureType ft,
                                                    String alias,
                                                    PropertyPath[] paths)

Ensures that all requested properties begin with a feature type step or an alias.

If no properties are specified at all, a single PropertyPath entry is created that selects the whole feature type.

Parameters:

ft - feature type that the requested properties refer to

alias - alias for the feature type, may be null

paths - requested properties, may not be null

Returns:

normalized paths

normalizePropertyPaths

public static List<PropertyPath>[] normalizePropertyPaths(MappedFeatureType[] fts,
                                                          String[] ftAliases,
                                                          PropertyPath[] paths)
                                                   throws PropertyPathResolvingException

Ensures that all requested properties begin with a feature type (or alias) step.

If no properties are specified for a feature type, a single PropertyPath entry is created that selects the whole feature type.

Parameters:

fts - feature types that the requested properties refer to

paths - requested properties, may not be null

Returns:

normalized paths

Throws:

PropertyPathResolvingException

determineFetchProperties

public static Map<MappedPropertyType,Collection<PropertyPath>> determineFetchProperties(MappedFeatureType ft,
                                                                                        String alias,
                                                                                        PropertyPath[] requestedPaths)
                                                                                 throws PropertyPathResolvingException

Determines the properties of the given feature type that have to be fetched based on the requested property paths.

Returns a helper Map that associates each (requested) property of the feature with the property paths that request it. Note that the returned helper map may contain more properties than specified. This behaviour is due to section 9.2 of the Web Feature Implementation Specification 1.1.0:

In the event that a WFS encounters a query that does not select all mandatory properties of a feature, the WFS will internally augment the property name list to include all mandatory property names.

Note that every requested property path must begin with a step that selects the given feature type.

Parameters:

ft - feature type

alias - alias for the feature type (may be null)

requestedPaths -

Returns:

Map, key class: MappedPropertyType, value class: Collection (of PropertyPath instances)

Throws:

PropertyPathResolvingException

determineSubPropertyPaths

public static PropertyPath[] determineSubPropertyPaths(MappedFeatureType featureType,
                                                       Collection<PropertyPath> propertyPaths)

Determines the sub property paths that are needed to fetch the given property paths for the also given property.

Parameters:

featureType -

propertyPaths -

Returns:

sub property paths that are needed to fetch the given property paths