/* * GeoTools - The Open Source Java GIS Toolkit * http://geotools.org * * (C) 2008, Open Source Geospatial Foundation (OSGeo) * * This library is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; * version 2.1 of the License. * * This library is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. */ package org.geotools.data; import java.net.URI; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.List; import org.opengis.filter.Filter; import org.opengis.filter.FilterFactory; import org.opengis.filter.expression.PropertyName; import org.opengis.filter.sort.SortBy; import org.opengis.referencing.crs.CoordinateReferenceSystem; import org.geotools.factory.CommonFactoryFinder; import org.geotools.factory.Hints; /** * Encapsulates a request for data, typically as: * <pre><code> * Query query = ... * myFeatureSource.getFeatures(query); * </code></pre> * * The query class is based on the Web Feature Server specification and offers a * few interesting capabilities such as the ability to sort results and use a filter * (similar to the WHERE clause in SQL). * <p> * Additional capabilities: * <ul> * <li> * {@linkplain #setMaxFeatures(int)} and {@linkplain #setStartIndex(Integer)} can be used * implement 'paging' through the data source's content. This is useful if, for example, the * FeatureSource has an upper limit on the number of features it can return in a single * request or you are working with limited memory. * </li> * <li> * {@linkplain #setHandle(String)} can be used to give the query a mnemonic name * which will appear in error reporing and logs. * </li> * <li> * {@linkplain #setCoordinateSystem(CoordinateReferenceSystem)} is used to to specify the * coordinate system that retrieved features will be "forced" into. * This is often used to correct a feature source when the application and the data * format have different ideas about the coordinate system (for example, the "axis order" * issue). * </li> * <li> * {@linkplain #setCoordinateSystemReproject(CoordinateReferenceSystem)} is used to ask for * the retrieved features to be reproejcted. * </li> * </ul> * * Vendor specific: * <ul> * <li>{@linkplain setHints(Hints)} is used to specify venfor specific capabilities * provided by a feature source implementation. * </li> * </ul> * Example:<pre><code> * Filter filter = CQL.toFilter("NAME like '%land'"); * Query query = new Query( "countries", filter ); * * FeatureCollection features = featureSource.getFeatures( query ); * </code></pre> * * @author Chris Holmes * * @source $URL$ * @version $Id$ */ public class Query { /** * When specifying properties to select, setting this hint flag true tells the datastore * to include mandatory properties (i.e. properties with minOccurs >= 1) in the end result, * irrespective of whether they are not included in the list of properties. * * Datastores may implement adding all mandatory properties to the end result * when this flag is set to true. For example: * * Object includeProps = query.getHints().get(Query.INCLUDE_MANDATORY_PROPS); * if (includeProps instanceof Boolean && ((Boolean)includeProps).booleanValue()) { * query.setProperties (DataUtilities.addMandatoryProperties(type, query.getProperties())); * } * */ public static Hints.Key INCLUDE_MANDATORY_PROPS = new Hints.Key(Boolean.class); /** * Constant (actually null) used to represent no namespace restrictions on the returned result, should be considered ANY_URI */ public static final URI NO_NAMESPACE = null; /** So getMaxFeatures does not return null we use a very large number. */ public static final int DEFAULT_MAX = Integer.MAX_VALUE; /** * Implements a query that will fetch all features from a datasource. This * query should retrieve all properties, with no maxFeatures, no * filtering, and the default featureType. */ public static final Query ALL = new ALLQuery(); /** * Implements a query that will fetch all the FeatureIDs from a datasource. * This query should retrieve no properties, with no maxFeatures, no * filtering, and the a featureType with no attribtues. */ public static final Query FIDS = new FIDSQuery(); /** * A constant (empty String array) that can be used with * {@linkplain #setPropertyNames(String[])} to indicate that no * properties are to be retrieved. * <p> * Note the query will still return a result - limited to FeatureIDs. * </p> */ public static final String[] NO_NAMES = new String[0]; /** * A constant (value {@code null}) that can be used with * {@linkplain #setPropertyNames(String[])} to indicate that all properties * are to be retrieved. */ public static final String[] ALL_NAMES = null; /** * A constant (empty String array) that can be used with * {@linkplain #setProperties(Collection<PropertyName>)} to indicate that no * properties are to be retrieved. * <p> * Note the query will still return a result - limited to FeatureIDs. * </p> */ public static final List<PropertyName> NO_PROPERTIES = Collections.<PropertyName>emptyList(); /** * A constant (value {@code null}) that can be used with * {@linkplain #setProperties(Collection<PropertyName>)} to indicate that all properties * are to be retrieved. */ public static final List<PropertyName> ALL_PROPERTIES = null; /** The properties to fetch */ protected List<PropertyName> properties; /** The maximum numbers of features to fetch */ protected int maxFeatures = Query.DEFAULT_MAX; /** The index of the first feature to process */ protected Integer startIndex = null; /** The filter to constrain the request. */ protected Filter filter = Filter.INCLUDE; /** The typeName to get */ protected String typeName; /** The namespace to get */ protected URI namespace =Query.NO_NAMESPACE; /** The handle associated with this query. */ protected String handle; /** Coordinate System associated with this query */ protected CoordinateReferenceSystem coordinateSystem; /** Reprojection associated associated with this query */ protected CoordinateReferenceSystem coordinateSystemReproject; /** Sorting for the query */ protected SortBy[] sortBy; /** The version according to WFS 1.0 and 1.1 specs */ protected String version; /** The hints to be used during query execution */ protected Hints hints; /** * Default constructor. Use setter methods to configure the Query * before use (the default Query will retrieve all features). */ public Query() { // no arg } /** * Constructor. * * @param typeName the name of the featureType to retrieve */ public Query( String typeName ){ this( typeName, Filter.INCLUDE ); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param filter the OGC filter to constrain the request. */ public Query(String typeName, Filter filter) { this( typeName, filter, Query.ALL_NAMES ); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param filter the OGC filter to constrain the request. * @param properties an array of the properties to fetch. */ public Query(String typeName, Filter filter, String[] properties) { this( typeName, null, filter, Query.DEFAULT_MAX, properties, null ); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param filter the OGC filter to constrain the request. * @param properties a list of the properties to fetch. */ public Query(String typeName, Filter filter, List<PropertyName> properties) { this( typeName, null, filter, Query.DEFAULT_MAX, properties, null ); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param filter the OGC filter to constrain the request. * @param maxFeatures the maximum number of features to be returned. * @param propNames an array of the properties to fetch. * @param handle the name to associate with this query. */ public Query(String typeName, Filter filter, int maxFeatures, String[] propNames, String handle) { this(typeName, null, filter, maxFeatures, propNames, handle ); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param filter the OGC filter to constrain the request. * @param maxFeatures the maximum number of features to be returned. * @param properties a list of the properties to fetch. * @param handle the name to associate with this query. */ public Query(String typeName, Filter filter, int maxFeatures, List<PropertyName> properties, String handle) { this(typeName, null, filter, maxFeatures, properties, handle ); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param namespace Namespace for provided typeName, or null if unspecified * @param filter the OGC filter to constrain the request. * @param maxFeatures the maximum number of features to be returned. * @param propNames an array of the properties to fetch. * @param handle the name to associate with the query. */ public Query( String typeName, URI namespace, Filter filter, int maxFeatures, String[] propNames, String handle) { this.typeName = typeName; this.filter = filter; this.namespace = namespace; this.maxFeatures = maxFeatures; this.handle = handle; setPropertyNames(propNames); } /** * Constructor. * * @param typeName the name of the featureType to retrieve. * @param namespace Namespace for provided typeName, or null if unspecified * @param filter the OGC filter to constrain the request. * @param maxFeatures the maximum number of features to be returned. * @param properties a list of the property names to fetch. * @param handle the name to associate with the query. */ public Query( String typeName, URI namespace, Filter filter, int maxFeatures, List<PropertyName> propNames, String handle) { this.typeName = typeName; this.filter = filter; this.namespace = namespace; this.maxFeatures = maxFeatures; this.handle = handle; this.properties = propNames==null? null : new ArrayList<PropertyName>(propNames); } /** * Copy contructor. * * @param query the query to copy */ public Query(Query query) { this(query.getTypeName(), query.getNamespace(), query.getFilter(), query.getMaxFeatures(), query.getProperties(), query.getHandle()); this.sortBy = query.getSortBy(); this.coordinateSystem = query.getCoordinateSystem(); this.coordinateSystemReproject = query.getCoordinateSystemReproject(); this.version = query.getVersion(); this.hints = query.getHints(); this.startIndex = query.getStartIndex(); } /** * Get the names of the properties that this Query will retrieve as part of * the returned {@linkplain org.geotools.feature.FeatureCollection}. * * @return the attributes to be used in the returned FeatureCollection. * * @see #retrieveAllProperties() * * @task REVISIT: make a FidProperties object, instead of an array size 0. * I think Query.FIDS fills this role to some degree. * Query.FIDS.equals( filter ) would meet this need? */ public String[] getPropertyNames() { if (properties == null) { return null; } String[] propertyNames = new String[properties.size()]; for (int i=0; i< properties.size(); i++) { PropertyName propertyName = properties.get(i); if( propertyName != null){ String xpath = propertyName.getPropertyName(); propertyNames[i] = xpath; } } return propertyNames; } /** * Set the names of the properties that this Query should retrieve as part of * the returned {@linkplain org.geotools.feature.FeatureCollection}. * As well as an array of names, the following constants can be used: * <ul> * <li> * {@linkplain #ALL_NAMES} to retrieve all properties. * </li> * <li> * {@linkplain #NO_NAMES} to indicate no properties are required, just feature IDs. * </li> * </ul> * The available properties can be determined with {@linkplain FeatureSource#getSchema()}. * If properties that are not part of the source's schema are requested * an exception will be thrown. * * @param propNames the names of the properties to retrieve or one of * {@linkplain #ALL_NAMES} or {@linkplain #NO_NAMES}. */ public void setPropertyNames(String[] propNames) { if (propNames == null) { properties = ALL_PROPERTIES; return; } final FilterFactory ff = CommonFactoryFinder.getFilterFactory(null); properties = new ArrayList<PropertyName>(propNames.length); for (int i=0; i< propNames.length; i++) { String xpath = propNames[i]; if(xpath != null ){ properties.add(ff.property(xpath)); } } } /** * Get the names of the properties that this Query will retrieve values for * as part of the returned {@linkplain org.geotools.feature.FeatureCollection}. * * @return the xpath expressions to be used in the returned FeatureCollection. * * @see #retrieveAllProperties() */ public List<PropertyName> getProperties() { if (properties == ALL_PROPERTIES) { return ALL_PROPERTIES; } return Collections.<PropertyName>unmodifiableList(properties) ; } /** * Set the names of the properties that this Query should retrieve as part of * the returned {@linkplain org.geotools.feature.FeatureCollection}. * As well as an array of names, the following constants can be used: * <ul> * <li> * {@linkplain #ALL_PROPERTIES} to retrieve all properties. * </li> * <li> * {@linkplain #NO_PROPERTIES} to indicate no properties are required, just feature IDs. * </li> * </ul> * The available properties can be determined with {@linkplain FeatureSource#getSchema()}. * If properties that are not part of the source's schema are requested * an exception will be thrown. * * @param propNames the names of the properties to retrieve or one of * {@linkplain #ALL_PROPERTIES} or {@linkplain #NO_PROPERTIES}. */ public void setProperties(List<PropertyName> propNames) { this.properties = propNames== ALL_PROPERTIES ? ALL_PROPERTIES : new ArrayList<PropertyName>(propNames); } /** * Set the names of the properties that this Query should retrieve as part of * the returned {@linkplain org.geotools.feature.FeatureCollection}. * <p> * The available properties can be determined with {@linkplain FeatureSource#getSchema()}. * If properties that are not part of the source's schema are requested * an exception will be thrown. * * @param propNames the names of the properties to retrieve or * {@linkplain #ALL_NAMES}; an empty List can be passed in to * indicate that only feature IDs should be retrieved * * @task REVISIT: This syntax is really obscure. Consider having an fid or * featureID propertyName that datasource implementors look for * instead of looking to see if the list size is 0. */ public void setPropertyNames(List<String> propNames) { if (propNames == null) { this.properties = ALL_PROPERTIES; return; } final FilterFactory ff = CommonFactoryFinder.getFilterFactory(null); properties = new ArrayList<PropertyName>(propNames.size()); for (int i=0; i< propNames.size(); i++) { String xpath = propNames.get(i); if(xpath != null ){ properties.add(ff.property(xpath)); } } } /** * Convenience method to determine if the query should retrieve all * properties defined in the schema of the feature data source. This * is equivalent to testing if {@linkplain #getPropertyNames()} returns * {@linkplain #ALL_NAMES}. * * @return true if all properties will be retrieved by this Query; false * otherwise */ public boolean retrieveAllProperties() { return properties == null; } /** * Get the maximum number of features that will be retrieved by this * Query. * <p> * Note: This is the only method that is not directly out of the Query element in * the WFS specification. It is instead a part of a GetFeature request, which can * hold one or more queries. But each of those in turn will need a * maxFeatures, so it is needed here. * </p> * <p> * If the value returned here is max integer then the number of features * should not be limited. * * @return the maximum number of features that will be retrieved by * this query */ public int getMaxFeatures() { return this.maxFeatures; } /** * Check if this query allows an unlimited number of features to be returned. * <p> * @return true maxFeatures is less then zero, or equal to Integer.MAX_VALUE. */ public boolean isMaxFeaturesUnlimited(){ return maxFeatures < 0 || maxFeatures == Integer.MAX_VALUE; } /** * Sets the maximum number of features that should be retrieved by this query. * The default is to retrieve all features. * * @param maxFeatures the maximum number of features to retrieve */ public void setMaxFeatures(int maxFeatures) { this.maxFeatures = maxFeatures; } /** * Get the index of the first feature to retrieve. * * @return the index of the first feature to retrieve or {@code null} * if no start index is defined. */ public Integer getStartIndex(){ return this.startIndex; } /** * Set the index of the first feature to retrieve. This can be used in * conjuction with {@linkplain #setMaxFeatures(int) } to 'page' through * a feature data source. * * @param startIndex index of the first feature to retrieve or {@code null} * to indicate no start index * * @throws IllegalArgumentException if startIndex is less than 0 */ public void setStartIndex(Integer startIndex){ if(startIndex != null && startIndex.intValue() < 0){ throw new IllegalArgumentException("startIndex shall be a positive integer: " + startIndex); } this.startIndex = startIndex; } /** * Gets the filter used to define constraints on the features that will be * retrieved by this Query. * * @return The filter that defines constraints on the query. */ public Filter getFilter() { return this.filter; } /** * Sets the filter to constrain the features that will be retrieved by * this Query. If no filter is set all features will be retrieved (taking * into account any bounds set via {@linkplain #setMaxFeatures(int) } and * {@linkplain #setStartIndex(java.lang.Integer) }). * <p> * The default is {@linkplain Filter#INCLUDE}. * * @param filter the OGC filter which features must pass through to * be retrieved by this Query. */ public void setFilter(Filter filter) { this.filter = filter; } /** * Get the name of the feature type to be queried. * * @return the name of the feature type to be returned with this query. */ public String getTypeName() { return this.typeName; } /** * Sets the name of the feature type to be queried. If no typename is specified, * then the data source's default type will be used. When working with sources * such as shapefiles that only support one feature type this method can be ignored. * * @param typeName the name of the featureType to retrieve. */ public void setTypeName(String typeName) { this.typeName = typeName; } /** * Get the namespace of the feature type to be queried. * * @return the gml namespace of the feature type to be returned with this * query */ public URI getNamespace() { return namespace; } /** * Set the namespace of the feature type to be queried. * * @return the gml namespace of the feature type to be returned with this * query */ public void setNamespace(URI namespace) { this.namespace = namespace; } /** * Get the handle (mnemonic name) that will be associated with this Query. * The handle is used in logging and error reporting. * * @return the name to refer to this query. */ public String getHandle() { return this.handle; } /** * Set the handle (mnemonic name) that will be associated with this Query. * The handle is used in logging and error reporting. * * @param handle the name to refer to this query. */ public void setHandle(String handle) { this.handle = handle; } /** * From WFS Spec: The version attribute is included in order to * accommodate systems that support feature versioning. A value of {@linkplain #ALL} * indicates that all versions of a feature should be fetched. Otherwise * an integer, n, can be specified to return the n th version of a * feature. The version numbers start at '1' which is the oldest version. * If a version value larger than the largest version is specified then * the latest version is return. The default action shall be for the query * to return the latest version. Systems that do not support versioning * can ignore the parameter and return the only version that they have. * * @return the version of the feature to return, or null for latest. */ public String getVersion() { return version; } /** * Set the version of features to retrieve where this is supported by the * data source being queried. * @param version * @see #getVersion() getVersion() for explanation * @since 2.4 */ public void setVersion(String version) { this.version = version; } /** * Get the coordinate system that applies to features retrieved by this Query. * By default this is the coordinate system of the features in the data source * but this can be overriden via {@linkplain #setCoordinateSystem( CoordinateReferenceSystem )}. * * @return The coordinate system to be returned for Features from this * Query (override the set coordinate system). */ public CoordinateReferenceSystem getCoordinateSystem() { return coordinateSystem; } /** * Set the coordinate system to apply to features retrieved by this Query. * <p> * This denotes a request to <b>temporarily</b> override the coordinate system * contained in the feature data source being queried. The same coordinate * values will be used, but the features retrieved will appear in this * Coordinate System. * * <p> * This change is not persistant and only applies to the features * returned by this Query. If used in conjunction with {@link #getCoordinateSystemReproject()} * the reprojection will occur from {@link #getCoordinateSystem()} to * {@link #getCoordinateSystemReproject()}. * </p> * * @param system the coordinate system to apply to features retrieved by this Query */ public void setCoordinateSystem(CoordinateReferenceSystem system) { coordinateSystem = system; } /** * If reprojection has been requested, this returns the coordinate system * that features retrieved by this Query will be reprojected into. * * @return the coordinate system that features will be reprojected into (if set) * * @see #setCoordinateSystemReproject( CoordinateReferenceSystem ) */ public CoordinateReferenceSystem getCoordinateSystemReproject() { return coordinateSystemReproject; } /** * Request that features retrieved by this Query be reprojected into the * given coordinate system. * <p> * If used in conjunction with {@link #setCoordinateSystem(CoordinateReferenceSystem)} * the reprojection will occur from the overridden coordinate system to the system * specified here. * * @return the coordinate system that features should be reprojected into */ public void setCoordinateSystemReproject(CoordinateReferenceSystem system) { coordinateSystemReproject = system; } /** * SortBy results according to indicated property and order. * <p> * SortBy is part of the Filter 1.1 specification, it is referenced * by WFS1.1 and Catalog 2.0.x specifications and is used to organize * results. * </p> * The SortBy's are ment to be applied in order: * <ul> * <li>SortBy( year, ascending ) * <li>SortBy( month, decsending ) * </ul> * Would produce something like: <pre><code> * [year=2002 month=4],[year=2002 month=3],[year=2002 month=2], * [year=2002 month=1],[year=2003 month=12],[year=2002 month=4], * </code></pre> * </p> * <p> * * SortBy should be considered at the same level of abstraction as Filter, * and like Filter you may sort using properties not listed in * getPropertyNames. * </p> * * <p> * At a technical level the interface SortBy2 is used to indicate the * additional requirements of a GeoTools implementation. The pure * WFS 1.1 specification itself is limited to SortBy. * </p> * * @return SortBy array or order of application */ public SortBy[] getSortBy() { return sortBy; } /** * Sets the sort by information. * */ public void setSortBy(SortBy[] sortBy) { this.sortBy = sortBy; } /** * Get hints that have been set to control the query execution. * * @return hints that are set (may be empty) * * @see #setHints(Hints) setHints(Hints) for more explanation */ public Hints getHints() { if(hints == null){ hints = new Hints(); } return hints; } /** * Set hints to control the query execution. * <p> * Hints can control such things as: * <ul> * <li> the GeometryFactory to be used * <li> a generalization distance to be applied * <li> the fetch size to be used in JDBC queries * </ul> * The set of hints supported can be found by calling * {@linkplain org.geotools.data.FeatureSource#getSupportedHints() }. * <p> * Note: Data sources may ignore hints (depending on their values) and no * mechanism currently exists to discover which hints where actually used * during the query's execution. * @see Hints#FEATURE_DETACHED * @see Hints#JTS_GEOMETRY_FACTORY * @see Hints#JTS_COORDINATE_SEQUENCE_FACTORY * @see Hints#JTS_PRECISION_MODEL * @see Hints#JTS_SRID * @see Hints#GEOMETRY_DISTANCE * @see Hints#FEATURE_2D * * @param hints the hints to apply */ public void setHints(Hints hints) { this.hints = hints; } /** * Hashcode based on all parameters other than the handle. * * @return hascode for this Query */ @Override public int hashCode() { String[] n = getPropertyNames(); return ((n == null) ? (-1) : ((n.length == 0) ? 0 : (n.length | n[0].hashCode()))) | getMaxFeatures() | ((getFilter() == null) ? 0 : getFilter().hashCode()) | ((getTypeName() == null) ? 0 : getTypeName().hashCode()) | ((getVersion() == null) ? 0 : getVersion().hashCode()) | ((getCoordinateSystem() == null) ? 0 : getCoordinateSystem().hashCode()) | ((getCoordinateSystemReproject() == null) ? 0 : getCoordinateSystemReproject().hashCode()) | getStartIndex(); } /** * Equality based on all query parameters other than the handle. * * @param obj Other object to compare against * * @return true if this Query matches the other object; false otherwise */ @Override public boolean equals(Object obj) { if ((obj == null) || !(obj instanceof Query)) { return false; } if (this == obj) return true; Query other = (Query) obj; return Arrays.equals(getPropertyNames(), other.getPropertyNames()) && (retrieveAllProperties() == other.retrieveAllProperties()) && (getMaxFeatures() == other.getMaxFeatures()) && ((getFilter() == null) ? (other.getFilter() == null) : getFilter().equals(other.getFilter())) && ((getTypeName() == null) ? (other.getTypeName() == null) : getTypeName().equals(other.getTypeName())) && ((getVersion() == null) ? (other.getVersion() == null) : getVersion().equals(other.getVersion())) && ((getCoordinateSystem() == null) ? (other.getCoordinateSystem() == null) : getCoordinateSystem().equals(other.getCoordinateSystem())) && ((getCoordinateSystemReproject() == null) ? (other.getCoordinateSystemReproject() == null) : getCoordinateSystemReproject().equals(other.getCoordinateSystemReproject())) && (getStartIndex() == other.getStartIndex()) && (getHints() == null ? (other.getHints() == null) : getHints().equals(other.getHints())); } /** * Return a string representation of this Query. * * @return a string representation of this Query */ @Override public String toString() { StringBuffer returnString = new StringBuffer("Query:"); if (handle != null) { returnString.append(" [" + handle + "]"); } returnString.append("\n feature type: " + typeName); if (filter != null) { returnString.append("\n filter: " + filter.toString()); } returnString.append("\n [properties: "); if ((properties == null) || (properties.size() == 0)) { returnString.append(" ALL ]"); } else { for (int i = 0; i < properties.size(); i++) { returnString.append(properties.get(i)); if (i < (properties.size() - 1)) { returnString.append(", "); } } returnString.append("]"); } if(sortBy != null && sortBy.length > 0) { returnString.append("\n [sort by: "); for (int i = 0; i < sortBy.length; i++) { returnString.append(sortBy[i].getPropertyName().getPropertyName()); returnString.append(" "); returnString.append(sortBy[i].getSortOrder().name()); if (i < (sortBy.length - 1)) { returnString.append(", "); } } returnString.append("]"); } return returnString.toString(); } }