WFSRequestObjectHandler.java

/* (c) 2014 Open Source Geospatial Foundation - all rights reserved
 * (c) 2001 - 2013 OpenPlans
 * This code is licensed under the GPL 2.0 license, available at the root
 * application directory.
 */
package org.geoserver.monitor.ows.wfs;

import java.util.List;
import java.util.logging.Logger;

import javax.xml.namespace.QName;

import org.geoserver.catalog.Catalog;
import org.geoserver.catalog.FeatureTypeInfo;
import org.geoserver.monitor.ows.RequestObjectHandler;
import org.geoserver.monitor.MonitorConfig;
import org.geoserver.ows.util.OwsUtils;
import org.geotools.filter.visitor.ExtractBoundsFilterVisitor;
import org.geotools.geometry.jts.ReferencedEnvelope;
import org.geotools.util.logging.Logging;
import org.opengis.filter.Filter;
import org.opengis.filter.spatial.BBOX;
import org.opengis.geometry.BoundingBox;
import org.opengis.referencing.crs.CoordinateReferenceSystem;
import org.opengis.referencing.operation.TransformException;

public abstract class WFSRequestObjectHandler extends RequestObjectHandler {

    static final Logger LOGGER = Logging.getLogger(WFSRequestObjectHandler.class);
    
    // TODO: this should probably be handled as an update or extension to ExtractBoundsFilterVisitor
    ExtractBoundsFilterVisitor visitor = new ExtractBoundsFilterVisitor() {
        public Object visit( BBOX filter, Object data ) {
            if(data == null) {
                return null;
            }
            
            BoundingBox bbox = (BoundingBox) data;
                    
            BoundingBox bounds;
            try {
                bounds = filter.getBounds();
                if(bounds.getCoordinateReferenceSystem()==null){
                    bounds = ReferencedEnvelope.create(bounds, bbox.getCoordinateReferenceSystem());
                }
                bounds.toBounds(monitorConfig.getBboxCrs());
            } catch (TransformException ex) {
                // We're stuck so give up.
                return null;
            }
            
            bbox.include(bounds);
            return bbox;
        }

    };

    Catalog catalog;
    protected WFSRequestObjectHandler(String reqObjClassName, MonitorConfig config, Catalog catalog) {
        super(reqObjClassName, config);
        this.catalog = catalog;
    }

    protected String toString(Object name) {
        if (name instanceof QName) {
            QName qName = (QName) name;
            String prefix = qName.getPrefix();
            if (prefix == null || "".equals(prefix)) {
                prefix = qName.getNamespaceURI();
            }
            if (prefix == null || "".equals(prefix)) {
                prefix = null;
            }

            return prefix != null ? prefix + ":" + qName.getLocalPart() : qName.getLocalPart();
        }
        else {
            return name.toString();
        }
         
    }
    
    /**
     * Look up the CRS of the specified FeatureType
     */
    protected CoordinateReferenceSystem crsFromTypeName(QName typeName) {
            FeatureTypeInfo featureType = catalog.getFeatureTypeByName(typeName.getNamespaceURI(), typeName.getLocalPart());
            
            return featureType.getCRS();
    }
    
    // There are two slight differences between the different WFS requests in how they store
    // their filters.  These methods are overridden to regularize these differences.
    protected abstract List<Object> getElements(Object request);
    
    protected Object unwrapElement(Object element){
        return element;
    }
    protected CoordinateReferenceSystem getCrsFromElement(Object element) {
        if (OwsUtils.has(element, "typeName")) {
            return crsFromTypeName((QName) OwsUtils.get(element, "typeName"));
        }
        return null;
    }

    protected ReferencedEnvelope getBBoxFromElement(Object element) {
        return null;
    }

    @Override
    protected BoundingBox getBBox(Object request) {
        if(monitorConfig.getBboxMode()!=MonitorConfig.BboxMode.FULL){
            return null;
        }

        List<Object> elements = getElements(request);
        if (elements==null) return null;

        try {
            BoundingBox result = new ReferencedEnvelope(monitorConfig.getBboxCrs());
            for(Object e : elements){
                e = unwrapElement(e);

                //first ask for a bounding box directly
                ReferencedEnvelope bbox = getBBoxFromElement(e);
                if (bbox == null) {
                    // try to infer it from a filter of the request
                    // This is the default CRS for the layer being queried
                    CoordinateReferenceSystem defaultCrs = getCrsFromElement(e);
                    if (defaultCrs == null) {
                        continue;
                    }

                    Filter f = OwsUtils.has(e, "filter") ? (Filter) OwsUtils.get(e, "filter") : null;
                    if(f != null) {
                        ReferencedEnvelope startingBbox = new ReferencedEnvelope(defaultCrs);
                        bbox = (ReferencedEnvelope) f.accept(visitor, startingBbox);
                    }
                }

                if (bbox != null) {
                    result.include(bbox.toBounds(monitorConfig.getBboxCrs()));
                }
            }
            return result;
        } catch (TransformException ex) {
            LOGGER.warning("Could not Transform bounds to desired CRS");
            return null;
        }
    }
}