getfeatureinfokvpreader.java

电子地图服务器,搭建自己的地图服务

/* Copyright (c) 2001 - 2007 TOPP - www.openplans.org.  All rights reserved.
 * This code is licensed under the GPL 2.0 license, availible at the root
 * application directory.
 */
package org.vfny.geoserver.wms.requests;

import org.vfny.geoserver.Request;
import org.vfny.geoserver.ServiceException;
import org.vfny.geoserver.global.Data;
import org.vfny.geoserver.global.FeatureTypeInfo;
import org.vfny.geoserver.global.WMS;
import org.vfny.geoserver.wms.WmsException;
import org.vfny.geoserver.wms.servlets.WMService;

import java.util.Iterator;
import java.util.List;
import java.util.Map;
import java.util.NoSuchElementException;
import java.util.Set;
import java.util.logging.Logger;
import javax.servlet.http.HttpServletRequest;


/**
 * Builds a GetFeatureInfo request object given by a set of CGI parameters
 * supplied in the constructor.
 *
 * <p>
 * Request parameters:
 * </p>
 *
 * @author Gabriel Roldan, Axios Engineering
 * @version $Id: GetFeatureInfoKvpReader.java 7746 2007-11-13 15:38:35Z aaime $
 */
public class GetFeatureInfoKvpReader extends WmsKvpRequestReader {
    /** DOCUMENT ME! */
    private static final Logger LOGGER = org.geotools.util.logging.Logging.getLogger("org.vfny.geoserver.requests.readers.wms");

    /** the request wich will be built by getRequest method */
    private GetFeatureInfoRequest request;

    /** GetMap request reader used to parse the map context parameters needed. */
    private GetMapKvpReader getMapReader;

    /**
     * Creates a new GetMapKvpReader object.
     * @param kvpPairs Key Values pairs of the request
     * @param service The service handling the request
     */
    public GetFeatureInfoKvpReader(Map kvpPairs, WMService service) {
        super(kvpPairs, service);
        getMapReader = new GetMapKvpReader(kvpPairs, service);
    }

    /**
     * Produces a <code>GetMapRequest</code> instance by parsing the GetMap
     * mandatory, optional and custom parameters.
     *
     * @param httpRequest the servlet request who's application object holds
     *        the server configuration
     *
     * @return a <code>GetMapRequest</code> completely setted up upon the
     *         parameters passed to this reader
     *
     * @throws ServiceException DOCUMENT ME!
     * @throws WmsException DOCUMENT ME!
     */
    public Request getRequest(HttpServletRequest httpRequest)
        throws ServiceException {
        WMService service = (WMService) getServiceRef();
        WMS wms = service.getWMS();
        request = new GetFeatureInfoRequest(service);
        request.setHttpServletRequest(httpRequest);

        String version = getRequestVersion();
        request.setVersion(version);

        getMapReader.setStylesRequired(false);

        GetMapRequest getMapPart = (GetMapRequest) getMapReader.getRequest(httpRequest);
        request.setGetMapRequest(getMapPart);

        FeatureTypeInfo[] layers = parseLayers(wms);
        request.setQueryLayers(layers);

        String format = getValue("INFO_FORMAT");

        if (format == null) {
            //HACK: how we define the default info format?
            //Not sure I understand the question.  If we don't like it here
            //then put it as the default in the FeatureInfoRequest.  If
            //we want to allow users to be able to set it then we can put
            //it as a config parameter in the WMS service section. -ch
            format = "text/plain";
        }

        request.setInfoFormat(format);

        request.setFeatureCount(1); // DJB: according to the WMS spec (7.3.3.7 FEATURE_COUNT) this should be 1.  also tested for by cite

        try {
            int maxFeatures = Integer.parseInt(getValue("FEATURE_COUNT"));
            request.setFeatureCount(maxFeatures);
        } catch (NumberFormatException ex) {
            //do nothing, FEATURE_COUNT is optional
        }

        try {
            int x = Integer.parseInt(getValue("X"));
            int y = Integer.parseInt(getValue("Y"));
            request.setXPixel(x);
            request.setYPixel(y);
        } catch (NumberFormatException ex) {
            throw new WmsException("X and Y incorrectly specified");
        }

        String exceptionsFormat = getValue("EXCEPTIONS");
        request.setExeptionFormat(exceptionsFormat);

        return request;
    }

    /**
     * Obtains the FeatureTypeInfo objects of the layers to query
     * given by the <code>QUERY_LAYERS</code>parameter.
     *
     * @return the list of layers to query.
     *
     * @throws WmsException if the parameter <code>QUERY_LAYERS</code> does not
     * exists, has no layer names, or has at least an invalid layer name.
     */
    private FeatureTypeInfo[] parseLayers(WMS wms) throws WmsException {
        List layers = readFlat(getValue("QUERY_LAYERS"), INNER_DELIMETER);
        
        // expand base layers, if there is any
        if(wms.getBaseMapLayers() != null) {
            for (int i = 0; i < layers.size(); i++) {
                String layerGroup = (String) wms.getBaseMapLayers().get(layers.get(i));
                if(layerGroup != null) {
                    List layerGroupExpanded = readFlat(layerGroup, INNER_DELIMETER);
                    layers.remove(i);
                    layers.addAll(i, layerGroupExpanded);
                }
            }
        }
        
        // remove coverage layers, we cannot query them
        Data catalog = request.getWMS().getData();
        for (Iterator it = layers.iterator(); it.hasNext();) {
            String layerName = (String) it.next();
            if(catalog.getLayerType(layerName) != Data.TYPE_VECTOR)
                it.remove();
        }
        
        
        int layerCount = layers.size();
        if (layerCount == 0) {
            throw new WmsException("No QUERY_LAYERS has been requested, or no queriable layer in the request anyways", getClass().getName());
        }
        FeatureTypeInfo[] featureTypes = new FeatureTypeInfo[layerCount];
        

        String layerName = null;
        FeatureTypeInfo ftype = null;

        try {
            for (int i = 0; i < layerCount; i++) {
                layerName = (String) layers.get(i);
                ftype = catalog.getFeatureTypeInfo(layerName);
                featureTypes[i] = ftype;
            }
        } catch (NoSuchElementException ex) {
            throw new WmsException(ex, layerName + ": no such layer on this server",
                getClass().getName());
        }

        return featureTypes;
    }
}