wmsdispatcher.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.servlets;

import org.vfny.geoserver.servlets.Dispatcher;
import org.vfny.geoserver.util.requests.readers.DispatcherKvpReader;
import org.vfny.geoserver.util.requests.readers.KvpRequestReader;
import java.io.IOException;
import java.util.Map;
import java.util.logging.Logger;
import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;


/**
 * Routes requests made at the top-level URI to appropriate interface servlet.
 * Note that the logic of this method could be generously described as
 * 'loose.' It is not checking for request validity in any way (this is done
 * by the reqeust- specific servlets).  Rather, it is attempting to make a
 * reasonable guess as to what servlet to call, given that the client is
 * routing to the top level URI as opposed to the request-specific URI, as
 * specified in the GetCapabilities response. Thus, this is a convenience
 * method, which allows for some slight client laziness and helps explain to
 * lost souls/spiders what lives at the URL. Due to the string parsing, it is
 * much faster (and recommended) to use the URIs specified in the
 * GetCapabablities response.  Currently does not support post requests, but
 * most requests for this will likely come with get.
 *
 * @author Chris Holmes, TOPP
 * @version $Id: WmsDispatcher.java 7746 2007-11-13 15:38:35Z aaime $
 *
 * @task TODO: rework to work too for WMS servlets, and to get the servlets
 *       from ServletContext instead of having them hardcoded
 */

//JD: kill this class
public class WmsDispatcher extends Dispatcher {
    /** Class logger */
    private static Logger LOGGER = org.geotools.util.logging.Logging.getLogger("org.vfny.geoserver.servlets.wms");

    /**
     * Passes the Post method to the Get method, with no modifications.
     *
     * @param request The servlet request object.
     * @param response The servlet response object.
     *
     * @throws ServletException For any servlet problems.
     * @throws IOException For any io problems.
     *
     * @task REVISIT: This is not working yet, as we can't seem to figure out
     *       how to read the reader twice.  It must be read once to see what
     *       the request type is,  and again to actually analyze it.  But we
     *       haven't yet found the way  to read it twice.  There should be
     *       some way to do this, but it doesn't seem that important, as users
     *       who use post should be able to figure out which servlet to send
     *       it to. I'm removing DispatcherReaderXml and DispatcherHandler
     *       from cvs, so that they don't get in the 1.0 release.  If anyone
     *       attempts to implement this there are deleted versions in cvs.
     *       Check the attic on the webcvs, or just do a checkout with the
     *       rel_0_98 tag.
     */
    public void doPost(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        //BufferedReader tempReader = request.getReader();
        //String tempResponse = new String();
        //int targetRequest = 0;
        LOGGER.finer("got to post request");

        //DJB: adding parital POST support for SLD-POST.
        //     currently the only type of POST request we support is GetMap
        //     So chris' comments above dont apply - we just assume its GetMap and we dont have to read twice.
        // 
        int targetRequest = Dispatcher.GET_MAP_REQUEST;
        doResponse(true, request, response, targetRequest);
    }

    /**
     * Handles all Get requests.  This method implements the main matching
     * logic for the class.
     *
     * @param request The servlet request object.
     * @param response The servlet response object.
     *
     * @throws ServletException For any servlet problems.
     * @throws IOException For any io problems.
     */
    public void doGet(HttpServletRequest request, HttpServletResponse response)
        throws ServletException, IOException {
        int targetRequest = 0;

        // Examine the incoming request and create appropriate server objects
        //  to deal with each request
        //              try { 
        if (request.getQueryString() != null) {
            Map kvPairs = KvpRequestReader.parseKvpSet(request.getQueryString());
            targetRequest = DispatcherKvpReader.getRequestType(kvPairs);
        } else {
            targetRequest = UNKNOWN;

            //throw exception
        }

        doResponse(false, request, response, targetRequest);
    }

    protected void doResponse(boolean isPost, HttpServletRequest request,
        HttpServletResponse response, int req_type) throws ServletException, IOException {
        HttpServlet dispatched;
        LOGGER.finer("req_type is " + req_type);

        //JD: kill this
        //        switch (req_type) {
        //        case GET_CAPABILITIES_REQUEST:
        //            dispatched = new Capabilities();
        //
        //            break;
        //
        //        case GET_MAP_REQUEST:
        //            dispatched = new GetMap();
        //
        //            break;
        //            
        //        case GET_FEATURE_INFO_REQUEST:
        //            dispatched = new GetFeatureInfo();
        //
        //            break;   
        //
        //        case DESCRIBE_LAYER_REQUEST:
        //            dispatched = new DescribeLayer();
        //
        //            break;   
        //
        //        case GET_LEGEND_GRAPHIC_REQUEST:
        //            dispatched = new GetLegendGraphic();
        //
        //            break;   
        //        default:
        //            dispatched = null;
        //        }
        //
        //        if ((dispatched != null))  //DJB: removed "&& !isPost" because we are partially supportin POST now
        //        {
        //            dispatched.init(servletConfig); //only needed for init hack, see
        //            dispatched.service(request, response);
        //        } else 
        //        {
        //            String message;
        //
        //            if (isPost) {
        //                message = "Post requests are not supported with the dispatcher "
        //                    + "servlet.  Please try the request using the appropriate "
        //                    + "request servlet, such as GetCapabilities or GetFeature";
        //            } else {
        //                message = "No wms kvp request recognized.  The REQUEST parameter"
        //                    + " must be one of GetMap or GetCapabilities";
        //            }
        //            
        //            HttpSession session = request.getSession();
        //            ServletContext context = session.getServletContext();
        //
        //            GeoServer geoServer = (GeoServer) context.getAttribute(GeoServer.WEB_CONTAINER_KEY);
        //            
        //            WmsException wmse = new WmsException(message);
        //            String tempResponse = wmse.getXmlResponse(geoServer.isVerboseExceptions(), request);
        //
        //            response.setContentType(geoServer.getCharSet().toString());
        //            response.getWriter().write(tempResponse);
        //        }
    }
}