mapinformationrenderer.java

esri的ArcGIS Server超级学习模板程序（for java）

package com.esri.solutions.jitk.web.faces.renderkit.xml.ajax;

import java.text.DecimalFormat;
import org.apache.log4j.Logger;

import javax.faces.component.UIComponent;
import javax.faces.context.FacesContext;

import org.w3c.dom.Element;

import com.esri.adf.web.data.WebContext;
import com.esri.adf.web.data.WebMap;
import com.esri.adf.web.faces.component.MapControl;
import com.esri.adf.web.faces.renderkit.xml.ajax.AJAXRenderer;
import com.esri.adf.web.util.XMLUtil;

/**
 * AJAXRenderer to render current extent & scale of map
 */
public class MapInformationRenderer implements AJAXRenderer {
	private static Logger _logger = Logger.getLogger(MapInformationRenderer.class.getName());
  
	@SuppressWarnings("unchecked")
	public Class getControlClass() {
		return MapControl.class;
	}
  
	public Object getOriginalState(UIComponent component) {
		MapControl mapControl = (MapControl) component;
		WebMap webMap = mapControl.getWebMap();
		return webMap.getCurrentExtent();
	}
  
	private String convertScale(double scale){
		DecimalFormat df = new DecimalFormat("###,###,###,###");
		String str = df.format(scale);

		String scaleStr = "1:" + str;

		if ((scale < 1) && (scale != 0.0)) {
			scale = 1 / scale;
			str = df.format(scale);
			scaleStr = df.format(str) + ":1";
		} else if (scale == 0.0) {
			_logger.error("Map scale reported as zero");
		}

		return scaleStr;
	}

	private String getDescription(String disp){
		try {
			String vstart = "\"";
			String[] vs = disp.split(vstart);
			return vs[1];
		} catch(Exception e) {
			_logger.error("Not a jitk task element", e);
		}
	
		return null;
	}  
  
	public void renderAjaxResponse(FacesContext facesContext, UIComponent component, Object state, boolean isEventSource, Element parentElement) {
		MapControl mapControl = (MapControl) component;

		WebMap webMap = mapControl.getWebMap();

		try {
			WebContext webContext = webMap.getWebContext();
      
			//render jitk-map-information tag
			Element rootElement = XMLUtil.createElement("jitk-map-information", null, parentElement);

			//render information about map's extent
			String def = webContext.getSpatialReferenceDefinitionString().replaceAll("_", " ");
			String desc = getDescription(def);
			XMLUtil.createElement("map-id", mapControl.getClientId(facesContext), rootElement);
			XMLUtil.createElement("map-projection", def, rootElement);
			XMLUtil.createElement("map-projection-name", desc, rootElement);
			XMLUtil.createElement("map-scale", convertScale(webMap.getMapScale()), rootElement);
		} catch (Exception e) {
			_logger.warn("Unable to encode xml.", e);
		}
	}
}