wmsplugin.java

openmap java写的开源数字地图程序. 用applet实现,可以像google map 那样放大缩小地图.

/* **********************************************************************
 * $Source: /cvs/distapps/openmap/src/openmap/com/bbn/openmap/plugin/wms/WMSPlugIn.java,v $
 * $Revision: 1.3.2.2 $
 * $Date: 2006/01/13 21:04:22 $
 * $Author: dietrick $
 *
 * Code provided by Raj Singh, [e-mail]
 * Updates provided by Holger Kohler, [e-mail]
 * Raj Singh updates in July 2002 to:
 *   - support WMS versions 1.0.8, 1.1.0 and 1.1.1
 *   - make JPEG image quality setting adjustable
 * *********************************************************************
 */

package com.bbn.openmap.plugin.wms;

import java.util.NoSuchElementException;
import java.util.Properties;
import java.util.StringTokenizer;

import com.bbn.openmap.image.ImageServerConstants;
import com.bbn.openmap.image.WMTConstants;
import com.bbn.openmap.plugin.WebImagePlugIn;
import com.bbn.openmap.proj.Projection;
import com.bbn.openmap.util.Debug;
import com.bbn.openmap.util.PropUtils;

/**
 * This class asks for an image from an OpenGIS compliant Web Map Server (WMS).
 * Make sure that OpenMap is using the LLXY projection, because this plugin is
 * only asking for images that are in the Spatial Reference System EPS 4326
 * projection, and anything else won't match up. This class will be growing to
 * be more interactive with the WMS.
 * 
 * It has some properties that you can set in the openmap.properties file:
 * 
 * <pre>
 *    
 *     #For the plugin layer, add wms_plugin to openmap.layers list
 *     wms_plugin=com.bbn.openmap.plugin.wms.WMSPlugIn
 *     wms_plugin.wmsserver=A URL for the WMS server (eg. http://host.domain.name/servlet/com.esri.wms.Esrimap)
 *     wms_plugin.wmsversion=OpenGIS WMS version number (eg. 1.1.0)
 *     wms_plugin.format=image format (eg. JPEG, GIF, PNG from WMTConstants.java)
 *     wms_plugin.transparent=true or false, depends on imageformat
 *     wms_plugin.backgroundcolor=RGB hex string (RRGGBB)
 *     wms_plugin.layers=comma separated list of map layer names (eg. SDE.SASAUS_BND_COASTL,SDE.SASAUS_BND_POLBNDL)
 *     wms_plugin.styles=comma separated list of layer rendering styles corresponding to the layers listed
 *     wms_plugin.vendorspecificnames=comma separated list of vendor specific parameter names in order (eg. SERVICENAME)
 *     wms_plugin.vendorspecificvalues=comma separated list of vendor specific parameter values in order (eg. default)
 *     
 * </pre>
 * 
 * <p>
 * One of the best demo WMS servers can be found at:
 * http://demo.cubewerx.com/demo/cubeserv/cubeserv.cgi
 */
public class WMSPlugIn extends WebImagePlugIn implements ImageServerConstants {

    /** URL to the server script that responds to WMS map requests */
    protected String wmsServer = null;
    /** GIF, PNG, JPEG, etc. (anything the server supports) */
    protected String imageFormat = null;
    /**
     * If using a lossy image format, such as jpeg, set this to high, medium or
     * low
     */
    protected String imageQuality = "MEDIUM";
    /** Specify the color for non-data areas of the image in r,g,b */
    protected String backgroundColor = null;
    /** true=make the backgroundColor transparent */
    protected String transparent = null;
    /** version of the Web map server spec the server supports */
    protected String wmsVersion = null;
    /** Comma-separated list of layer names */
    protected String layers = null;
    /** Comma-separated list of style names */
    protected String styles = null;
    /** Comma-separated list of vendor specific parameter names */
    protected String vendorSpecificNames = null;
    /** Comma-separated list of vendor specific parameter values */
    protected String vendorSpecificValues = null;
    /** Same as wmsServer */
    protected String queryHeader = null;
    /** Keyword for map request. Changes to MAP for WMS version 1.0.0 */
    protected String mapRequestName = WMTConstants.GETMAP;
    /**
     * Keyword for error handling. Changes to INIMAGE for WMS version under
     * 1.1.0. Changes to application/vnd.ogc.se+inimage for versions greater
     * than 1.1.1
     */
    protected String errorHandling = "application/vnd.ogc.se_inimage";

    public final static String WMSNameProperty = "wmsname";
    public final static String WMSServerProperty = "wmsserver";
    public final static String ImageFormatProperty = "format";
    public final static String BackgroundColorProperty = "backgroundcolor";
    public final static String TransparentProperty = "transparent";
    public static final String WMSVersionProperty = "wmsversion";
    public static final String LayersProperty = "layers";
    public static final String StylesProperty = "styles";
    public static final String VendorSpecificNamesProperty = "vendorspecificnames";
    public static final String VendorSpecificValuesProperty = "vendorspecificvalues";
    /** integer identifier for high image quality */
    public static final int LOSSY_IMAGE_QUALITY_HIGH = 2;
    /** integer identifier for medium image quality */
    public static final int LOSSY_IMAGE_QUALITY_MEDIUM = 1;
    /** integer identifier for low image quality */
    public static final int LOSSY_IMAGE_QUALITY_LOW = 0;

    public WMSPlugIn() {}

    /**
     * Add new layers to the server request, using the default style.
     */
    public void addLayers(String[] ls) {
        addLayers(ls, null);
    }

    /**
     * Add new layers to the server request, using specified styles.
     */
    public void addLayers(String[] ls, String[] st) {

        // DFD - do they have to be the same length? How about we just
        // use the styles we have for that number of layers, and let
        // the defaults take over for the rest.

        // if (ls.length != st.length) {
        // return null;
        // }

        for (int j = 0; j < ls.length; j++) {
            layers += "," + ls[j];

            // Put some other checks in here instead of the length
            // check above.
            if (st == null || j >= st.length || st[j] == null) {
                styles += ",";
            } else {
                styles += "," + st[j];
            }
        }
    }

    /**
     * Create the query to be sent to the server, based on current settings.
     */
    public String createQueryString(Projection p) {

        if (queryHeader == null) {
            return null;
        }

        String bbox = "undefined";
        String height = "undefined";
        String width = "undefined";

        if (p != null) {
            bbox = Double.toString(p.getUpperLeft().getLongitude()) + ","
                    + Double.toString(p.getLowerRight().getLatitude()) + ","
                    + Double.toString(p.getLowerRight().getLongitude()) + ","
                    + Double.toString(p.getUpperLeft().getLatitude());
            height = Integer.toString(p.getHeight());
            width = Integer.toString(p.getWidth());
        }

        StringBuffer buf = new StringBuffer(queryHeader);
        buf.append("?" + "VERSION" + "=" + wmsVersion + "&"
                + WMTConstants.REQUEST + "=" + mapRequestName + "&"
                + WMTConstants.SRS + "=" + "EPSG:4326" + "&"
                + WMTConstants.BBOX + "=" + bbox + "&" + WMTConstants.HEIGHT
                + "=" + height + "&" + WMTConstants.WIDTH + "=" + width + "&"
                + WMTConstants.EXCEPTIONS + "=" + errorHandling);

        if (imageFormat != null) {
            buf.append("&" + FORMAT + "=" + imageFormat);

            String baseImageFormat = imageFormat;
            if (baseImageFormat.indexOf('/') > 0)
                baseImageFormat = baseImageFormat.substring(baseImageFormat.indexOf('/'));
            if (baseImageFormat.equals(WMTConstants.IMAGEFORMAT_JPEG)) {
                buf.append("&quality=" + imageQuality);
            }
        }

        if (transparent != null) {
            buf.append("&" + TRANSPARENT + "=" + transparent);
        }

        if (backgroundColor != null) {
            buf.append("&" + BGCOLOR + "=" + backgroundColor);
        }

        if (layers != null) {
            buf.append("&" + LAYERS + "=" + layers);
        }

        if (styles != null) {
            buf.append("&" + STYLES + "=" + styles);
        }

        if (Debug.debugging("wms")) {
            Debug.output("query string: " + buf);
        }

        /*
         * Included to allow for one or more vendor specific parameters to be
         * specified such as ESRI's ArcIMS's "ServiceName" parameter.
         */
        if (vendorSpecificNames != null) {
            if (vendorSpecificValues != null) {
                StringTokenizer nameTokenizer = new StringTokenizer(vendorSpecificNames, ",");
                StringTokenizer valueTokenizer = new StringTokenizer(vendorSpecificValues, ",");
                String paramName = null;
                String paramValue = null;
                while (nameTokenizer.hasMoreTokens()) {
                    try {
                        paramName = nameTokenizer.nextToken();
                        paramValue = valueTokenizer.nextToken();
                        buf.append("&" + paramName + "=" + paramValue);
                    } catch (NoSuchElementException e) {
                        if (Debug.debugging("wms")) {
                            Debug.output("WMSPlugIn.getRectangle(): "
                                    + "parameter \"" + paramName
                                    + "\" has no value");
                        }
                    }
                }
            }
        }
        return buf.toString();
    }

    /**
     * Method to set the properties in the PropertyConsumer. The prefix is a
     * string that should be prepended to each property key (in addition to a
     * separating '.') in order for the PropertyConsumer to uniquely identify
     * properies meant for it, in the midst of Properties meant for several
     * objects.
     * 
     * @param prefix a String used by the PropertyConsumer to prepend to each
     *        property value it wants to look up -
     *        setList.getProperty(prefix.propertyKey). If the prefix had already
     *        been set, then the prefix passed in should replace that previous
     *        value.
     * 
     * @param setList a Properties object that the PropertyConsumer can use to
     *        retrieve expected properties it can use for configuration.
     */
    public void setProperties(String prefix, Properties setList) {
        super.setProperties(prefix, setList);
        prefix = PropUtils.getScopedPropertyPrefix(prefix);