GeoTools是一个Java软件包地理实现。
WMS是一种服务设计理念。
由上图可见，后端一共有三个函数GetCapabilities、GetMap和GetFeatureInfo，根据接收到的客户端的参数来分别进行调用。并将结果返回给客户端，WMS一般是返回图像格式的文件。
基于GeoTools的WMS的设计与实现，可以直接看GeoServer，它就是基于GeoTools的WMS实现。而且还包含了Jetty服务器，可以直接使用。当然也可以使用War包版本，放在Tomcat服务器下面。
第一步：拦截请求参数
public void doService(HttpServletRequest request, HttpServletResponse response) throws IOException { Map map = request.getParameterMap(); Map param = new HashMap(); for (String k : map.keySet()) { String s1 = ""; if (param.containsKey(k.toUpperCase())) { s1 = param.get(k.toUpperCase()) + ","; } String[] s2 = (String[]) map.get(k); for (int i = 0; i < s2.length; i++) { s1 += s2[i] + (i == 0 ? "" : ","); } param.put(k.toUpperCase(), s1); } if (!param.containsKey("REQUEST")) { WMSException.exception(response); } else { String wmsRequest = param.get("REQUEST"); if (wmsRequest.equals("GetCapabilities")) { GetCapabilitiesRequest gcr = new GetCapabilitiesRequest(param); doGetCapabilities(gcr, response); } else if (wmsRequest.equals("GetMap")) { GetMapRequest gmr = new GetMapRequest(param); doGetMap(gmr, response); } else if (wmsRequest.equals("GetFeatureInfo")) { GetFeatureInfoRequest gfr = new GetFeatureInfoRequest(param); doGetFeatureInfo(gfr, response); } else { WMSException.exception(response); } } }
第二步：
private static void addShapeLayer(String name) throws Exception { File file = new File("C:\data\" + name + ".shp"); File sldFile = new File("C:\data\" + name + ".sld"); FileDataStore store = FileDataStoreFinder.getDataStore(file); ((ShapefileDataStore) store).setStringCharset(Charset.forName("GB2312")); FeatureSource featureSource = store .getFeatureSource(); Configuration config = new SLDConfiguration(); Parser parser = new Parser(config); InputStream sld = new FileInputStream(sldFile); StyledLayerDescriptor styleSLD = (StyledLayerDescriptor) parser.parse(sld); Style style = SLD.defaultStyle(styleSLD); map.addLayer(featureSource, style); }
第三步：
private void doGetMap(GetMapRequest gmr, HttpServletResponse response) throws IOException { double x1, y1, x2, y2; int width, height; try { x1 = Double.parseDouble(gmr.getBBOX()[0]); y1 = Double.parseDouble(gmr.getBBOX()[1]); x2 = Double.parseDouble(gmr.getBBOX()[2]); y2 = Double.parseDouble(gmr.getBBOX()[3]); width = Integer.parseInt(gmr.getWidth()); height = Integer.parseInt(gmr.getHeight()); } catch (Exception e) { WMSException.exception(response); return; } // 设置输出范围 ReferencedEnvelope mapArea = new ReferencedEnvelope(x1, x2, y1, y2, crs); // 初始化渲染器 StreamingRenderer sr = new StreamingRenderer(); sr.setContext(map); // 初始化输出图像 BufferedImage bi = new BufferedImage(width, height, BufferedImage.TYPE_INT_ARGB); Graphics g = bi.getGraphics(); ((Graphics2D) g).setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON); ((Graphics2D) g).setRenderingHint(RenderingHints.KEY_TEXT_ANTIALIASING, RenderingHints.VALUE_TEXT_ANTIALIAS_ON); Rectangle rect = new Rectangle(0, 0, width, height); // 绘制地图 sr.paint((Graphics2D) g, rect, mapArea); // 编码图像 PNGEncodeParam encodeParam = PNGEncodeParam.getDefaultEncodeParam(bi); if (encodeParam instanceof PNGEncodeParam.Palette) { PNGEncodeParam.Palette p = (PNGEncodeParam.Palette) encodeParam; byte[] b = new byte[] { -127 }; p.setPaletteTransparency(b); } //将图像数据输出到Servlet相应中 response.setContentType("image/png"); ServletOutputStream out = response.getOutputStream(); com.sun.media.jai.codec.ImageEncoder encoder = ImageCodec .createImageEncoder("PNG", out, encodeParam); encoder.encode(bi.getData(), bi.getColorModel()); bi.flush(); }
第四步：
private void doGetFeatureInfo(GetFeatureInfoRequest gfr, HttpServletResponse response) throws IOException { double x1, y1, x2, y2; int width, height, i, j; try { x1 = Double.parseDouble(gfr.getBBOX()[0]); y1 = Double.parseDouble(gfr.getBBOX()[1]); x2 = Double.parseDouble(gfr.getBBOX()[2]); y2 = Double.parseDouble(gfr.getBBOX()[3]); width = Integer.parseInt(gfr.getWidth()); height = Integer.parseInt(gfr.getHeight()); i = Integer.parseInt(gfr.getI()); j = Integer.parseInt(gfr.getJ()); } catch (Exception e) { WMSException.exception(response); return; } // 计算点选范围的地图坐标 double cx1, cy1, cx2, cy2; cx1 = x1 * (width - i + 0.5 + GET_FEATURE_INFO_BUFFUR) / width + x2 * (i - 0.5 - GET_FEATURE_INFO_BUFFUR) / width; cx2 = x1 * (width - i + 0.5 - GET_FEATURE_INFO_BUFFUR) / width + x2 * (i - 0.5 + GET_FEATURE_INFO_BUFFUR) / width; cy1 = y1 * (j - 0.5 + GET_FEATURE_INFO_BUFFUR) / height + y2 * (height - j + 0.5 - GET_FEATURE_INFO_BUFFUR) / height; cy2 = y1 * (j - 0.5 - GET_FEATURE_INFO_BUFFUR) / height + y2 * (height - j + 0.5 + GET_FEATURE_INFO_BUFFUR) / height; ReferencedEnvelope clickArea = new ReferencedEnvelope(cx1, cx2, cy1, cy2, crs); MapLayer[] maplayers = map.getLayers(); FilterFactory2 ff = CommonFactoryFinder.getFilterFactory2(null); response.setContentType("text/html"); response.setCharacterEncoding("GBK"); PrintWriter out = response.getWriter(); out.println("location: " + ((cx1 + cx2) / 2.0) + ", " + ((cy1 + cy2) / 2.0) + "<br/>"); // 分别在每个图层中查找点选范围内的对象 for (int k = 0; k < maplayers.length; k++) { FeatureSource fs = (FeatureSource) maplayers[k].getFeatureSource(); String geometryPropertyName = fs.getSchema().getGeometryDescriptor().getLocalName(); Filter filter = ff.bbox(ff.property(geometryPropertyName), clickArea); FeatureCollection fc = fs.getFeatures(filter); SimpleFeatureType schema = fc.getSchema(); FeatureIterator fi = fc.features(); if (fi.hasNext()) { out.println("Selected feature(s) in layer ["+schema.getTypeName()+"]:<br/>"); while (fi.hasNext()) { SimpleFeature f = fi.next(); out.println("id:" + f.getID() + "<br/>"); for (AttributeDescriptor type : schema .getAttributeDescriptors()) { String name = type.getLocalName(); if (!name.equals(geometryPropertyName)) out.println(name + ":" + f.getProperty(name).getValue().toString() + "<br/>"); } out.println("<br/>"); } } } out.flush(); out.close(); }
>>geotools实现wmts服务：https://blog.csdn.net/weixin_43031156/article/details/131803424
