/*
* This is part of Geomajas, a GIS framework, http://www.geomajas.org/.
*
* Copyright 2008-2011 Geosparc nv, http://www.geosparc.com/, Belgium.
*
* The program is available in open source according to the GNU Affero
* General Public License. All contributions in this program are covered
* by the Geomajas Contributors License Agreement. For full licensing
* details, see LICENSE.txt in the project root.
*/
package org.geomajas.layer.wms.mvc;
import javax.imageio.ImageIO;
import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import org.geomajas.configuration.RasterLayerInfo;
import org.geomajas.global.ExceptionCode;
import org.geomajas.layer.LayerException;
import org.geomajas.layer.RasterLayer;
import org.geomajas.layer.wms.WmsHttpService;
import org.geomajas.layer.wms.WmsLayer;
import org.geomajas.service.ConfigurationService;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Controller;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RequestMethod;
import java.awt.Color;
import java.awt.Graphics2D;
import java.awt.image.BufferedImage;
import java.io.ByteArrayOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import java.util.StringTokenizer;
/**
* Spring MVC controller that maps a WMS request so it can be proxied to the real URL with authentication parameters.
*
* @author Pieter De Graef
*/
@Controller("/wms/**")
public class WmsController {
private final Logger log = LoggerFactory.getLogger(WmsController.class);
@Autowired
private ConfigurationService configurationService;
@Autowired
private WmsHttpService httpService;
// method provided for testing
protected void setHttpService(WmsHttpService httpService) {
this.httpService = httpService;
}
@RequestMapping(value = "/wms/**", method = RequestMethod.GET)
public void getWms(HttpServletRequest request, HttpServletResponse response) throws Exception {
// Search for the WMS layer:
String layerId = parseLayerId(request);
WmsLayer layer = getLayer(layerId);
if (layer == null) {
throw new LayerException(ExceptionCode.LAYER_NOT_FOUND, layerId);
}
RasterLayerInfo layerInfo = layer.getLayerInfo();
String url = layer.getBaseWmsUrl() + "?" + request.getQueryString();
InputStream stream = null;
try {
response.setContentType(layer.getFormat());
stream = httpService.getStream(url, layer.getAuthentication());
ServletOutputStream out = response.getOutputStream();
int b;
while ((b = stream.read()) >= 0 ) {
out.write(b);
}
} catch (Exception e) {
log.error("Cannot get original WMS image", e);
// Create an error image to make the reason for the error visible:
byte[] b = createErrorImage(layerInfo.getTileWidth(), layerInfo.getTileHeight(), e);
response.setContentType("image/png");
response.getOutputStream().write(b);
} finally {
if (null != stream) {
try {
stream.close();
} catch (IOException ioe) {
// ignore, closing anyway
}
}
}
}
// ------------------------------------------------------------------------
// Private methods:
// ------------------------------------------------------------------------
/** Get the layer ID out of the request URL.
*
* @param request servlet request
* @return layer id
*/
private String parseLayerId(HttpServletRequest request) {
StringTokenizer tokenizer = new StringTokenizer(request.getRequestURI(), "/");
String token = "";
while (tokenizer.hasMoreTokens()) {
token = tokenizer.nextToken();
}
return token;
}
/**
* Given a layer ID, search for the WMS layer.
*
* @param layerId layer id
* @return WMS layer or null if layer is not a WMS layer
*/
private WmsLayer getLayer(String layerId) {
RasterLayer layer = configurationService.getRasterLayer(layerId);
if (layer instanceof WmsLayer) {
return (WmsLayer) layer;
}
return null;
}
/**
* Create an error image should an error occur while fetching a WMS map.
*
* @param width image width
* @param height image height
* @param e exception
* @return error image
* @throws java.io.IOException oops
*/
private byte[] createErrorImage(int width, int height, Exception e) throws IOException {
String error = e.getMessage();
if (null == error) {
Writer result = new StringWriter();
PrintWriter printWriter = new PrintWriter(result);
e.printStackTrace(printWriter);
error = result.toString();
}
BufferedImage image = new BufferedImage(width, height, BufferedImage.TYPE_4BYTE_ABGR);
Graphics2D g = (Graphics2D) image.getGraphics();
g.setColor(Color.RED);
g.drawString(error, 10, height / 2);
ByteArrayOutputStream out = new ByteArrayOutputStream();
ImageIO.write(image, "PNG", out);
out.flush();
byte[] result = out.toByteArray();
out.close();
return result;
}
}