java查询WFS服务

在我们访问wfs服务时候，有时候会遇到前台访问时候的跨域问题。这里给出java访问的一个小例子。

 import java.io.BufferedReader;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.InputStreamReader;
 import java.io.UnsupportedEncodingException;
 import java.util.List;

 import org.apache.commons.httpclient.HttpClient;
 import org.apache.commons.httpclient.HttpException;
 import org.apache.commons.httpclient.methods.PostMethod;
 import org.apache.commons.httpclient.methods.StringRequestEntity;
 import org.apache.commons.httpclient.params.HttpMethodParams;
 import org.dom4j.Document;
 import org.dom4j.DocumentException;
 import org.dom4j.DocumentHelper;
 import org.dom4j.Element;
 import org.dom4j.QName;

 public class WFSUtil
 {

     /**
      * 得到过滤结果。名字默认是Poi
      *
      * @param keyWords
      * @param wfsUrl
      * @return
      * @throws HttpException
      * @throws IOException
      */
     public String findPointsXmlByKeywords(String[] keyWords, String wfsUrl,
             String wfsTitle, String layerName) throws HttpException,
             IOException
     {
         if (keyWords.length==0)
         {
             return "<root/>";
         }

         if (wfsTitle == null)
         {
             wfsTitle = "ST";
         }
         if (layerName == null)
         {
             layerName = "POI";
         }
         StringBuffer buffer = new StringBuffer(
                 "<?xml version='1.0' encoding='UTF-8'?>"
                         + "<wfs:GetFeature maxFeatures='100' service='WFS' version='1.1.0' "
                         + "xmlns:wfs='http://www.opengis.net/wfs' "
                         + "xmlns:gml='http://www.opengis.net/gml' "
                         + "xmlns:ogc='http://www.opengis.net/ogc' "
                         + "xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' "
                         + "xsi:schemaLocation='http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.1.0/wfs.xsd'>"
                         + "<wfs:Query typeName='" + layerName
                         + "' srsName='EPSG:4326'>"
                         + "<ogc:Filter xmlns:ogc='http://www.opengis.net/ogc'>");

         if (keyWords.length > 1)
         {
             buffer.append("<ogc:Or>");
             for (int i = 0; i < keyWords.length; i++)
             {
                 buffer.append(addPropertyIsLike(keyWords[i]));
             }
             buffer.append("</ogc:Or>");
         }
         else if (keyWords.length == 1)
         {
             buffer.append(addPropertyIsLike(keyWords[0]));
         }
         else
         {
             return null;
         }

         buffer.append("</ogc:Filter></wfs:Query></wfs:GetFeature>");
         PostMethod post = new PostMethod(wfsUrl);
         post.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET,
                 "utf-8");
         post.setRequestEntity(new StringRequestEntity(buffer.toString(),
                 "application/xml", "UTF-8"));
         HttpClient httpclient = new HttpClient();

         httpclient.executeMethod(post);

         InputStream xmlis = post.getResponseBodyAsStream();
         //确定读取编码为utf-8，不设置的话会用系统默认编码，例如在tomcat容器中，就可能乱码。
         BufferedReader br = new BufferedReader(new InputStreamReader(xmlis,"utf-8"));

         String tempbf;
         StringBuffer html = new StringBuffer(100);
         while ((tempbf = br.readLine()) != null)
         {
             html.append(tempbf);
         }
         // System.out.println(html.toString());
         return formatPoint(html.toString(),keyWords[0]);
     }

     private String addPropertyIsLike(String word)
     {
         String result = "";
         if (word != null && (!word.trim().isEmpty()))
         {
             result += "<ogc:PropertyIsLike wildCard='*' singleChar='.' escape='!'><ogc:PropertyName>POI_NAME</ogc:PropertyName><ogc:Literal>*"
                     + word + "*</ogc:Literal></ogc:PropertyIsLike>";
         }
         return result;
     }

     private String formatPoint(String xml,String keyWord)
     {
         try
         {
             Document doc = DocumentHelper.parseText(xml);

             Element root = doc.getRootElement();

             Element newRoot = DocumentHelper.createElement("root");
             newRoot.addAttribute("keyword", keyWord);

             List<Element> list = root.elements("featureMember");

             for (Element e : list)
             {
                 Element point = newRoot.addElement("point");
                 Element xs = e.element("Poi").element("X");
                 Element ys = e.element("Poi").element("Y");
                 if (xs != null&&ys!=null)
                 {
                     String text=xs.getText()+","+ys.getText();
                     point.addElement("xys").setText(text);
                     point.addElement("type").setText("point");
                     //point.addElement("x").setText(xs.getText());
                     //point.addElement("y").setText(ys.getText());
                 }
                 point.addElement("name").setText(
                         e.element("Poi").element("POI_NAME").getText());
                 point.addElement("address").setText(
                         e.element("Poi").element("ADDRESS").getText());
             }
             return newRoot.asXML();
             // throw new Exception("formatPoint is fail");
         }
         catch (DocumentException e)
         {
             // TODO Auto-generated catch block
             System.out.println("格式化失败！");
             e.printStackTrace();
         }

         return null;
     }

 }

这里面用到了commons.HttpClientj-3.1.jar和dom4j这两个jar包,如果是不同版本的jar包，写法可能略有不同。

欢迎交流：http://www.cnblogs.com/shizhongtao/p/3468664.html

有时间再整理下……