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。

  1 import java.io.BufferedReader;

  2 import java.io.IOException;

  3 import java.io.InputStream;

  4 import java.io.InputStreamReader;

  5 import java.io.UnsupportedEncodingException;

  6 import java.util.List;

  7 

  8 import org.apache.commons.httpclient.HttpClient;

  9 import org.apache.commons.httpclient.HttpException;

 10 import org.apache.commons.httpclient.methods.PostMethod;

 11 import org.apache.commons.httpclient.methods.StringRequestEntity;

 12 import org.apache.commons.httpclient.params.HttpMethodParams;

 13 import org.dom4j.Document;

 14 import org.dom4j.DocumentException;

 15 import org.dom4j.DocumentHelper;

 16 import org.dom4j.Element;

 17 import org.dom4j.QName;

 18 

 19 public class WFSUtil

 20 {

 21     

 22     /**

 23      * 得到过滤结果。名字默认是Poi

 24      * 

 25      * @param keyWords

 26      * @param wfsUrl

 27      * @return

 28      * @throws HttpException

 29      * @throws IOException

 30      */

 31     public String findPointsXmlByKeywords(String[] keyWords, String wfsUrl,

 32             String wfsTitle, String layerName) throws HttpException,

 33             IOException

 34     {

 35         if (keyWords.length==0)

 36         {

 37             return "<root/>";

 38         }

 39 

 40         if (wfsTitle == null)

 41         {

 42             wfsTitle = "ST";

 43         }

 44         if (layerName == null)

 45         {

 46             layerName = "POI";

 47         }

 48         StringBuffer buffer = new StringBuffer(

 49                 "<?xml version='1.0' encoding='UTF-8'?>"

 50                         + "<wfs:GetFeature maxFeatures='100' service='WFS' version='1.1.0' "

 51                         + "xmlns:wfs='http://www.opengis.net/wfs' "

 52                         + "xmlns:gml='http://www.opengis.net/gml' "

 53                         + "xmlns:ogc='http://www.opengis.net/ogc' "

 54                         + "xmlns:xsi='http://www.w3.org/2001/XMLSchema-instance' "

 55                         + "xsi:schemaLocation='http://www.opengis.net/wfs http://schemas.opengis.net/wfs/1.1.0/wfs.xsd'>"

 56                         + "<wfs:Query typeName='" + layerName

 57                         + "' srsName='EPSG:4326'>"

 58                         + "<ogc:Filter xmlns:ogc='http://www.opengis.net/ogc'>");

 59 

 60         if (keyWords.length > 1)

 61         {

 62             buffer.append("<ogc:Or>");

 63             for (int i = 0; i < keyWords.length; i++)

 64             {

 65                 buffer.append(addPropertyIsLike(keyWords[i]));

 66             }

 67             buffer.append("</ogc:Or>");

 68         }

 69         else if (keyWords.length == 1)

 70         {

 71             buffer.append(addPropertyIsLike(keyWords[0]));

 72         }

 73         else

 74         {

 75             return null;

 76         }

 77 

 78         buffer.append("</ogc:Filter></wfs:Query></wfs:GetFeature>");

 79         PostMethod post = new PostMethod(wfsUrl);

 80         post.getParams().setParameter(HttpMethodParams.HTTP_CONTENT_CHARSET,

 81                 "utf-8");

 82         post.setRequestEntity(new StringRequestEntity(buffer.toString(),

 83                 "application/xml", "UTF-8"));

 84         HttpClient httpclient = new HttpClient();

 85 

 86         httpclient.executeMethod(post);

 87 

 88         InputStream xmlis = post.getResponseBodyAsStream();

 89         //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。

 90         BufferedReader br = new BufferedReader(new InputStreamReader(xmlis,"utf-8"));

 91 

 92         String tempbf;

 93         StringBuffer html = new StringBuffer(100);

 94         while ((tempbf = br.readLine()) != null)

 95         {

 96             html.append(tempbf);

 97         }

 98         // System.out.println(html.toString());

 99         return formatPoint(html.toString(),keyWords[0]);

100     }

101 

102     private String addPropertyIsLike(String word)

103     {

104         String result = "";

105         if (word != null && (!word.trim().isEmpty()))

106         {

107             result += "<ogc:PropertyIsLike wildCard='*' singleChar='.' escape='!'><ogc:PropertyName>POI_NAME</ogc:PropertyName><ogc:Literal>*"

108                     + word + "*</ogc:Literal></ogc:PropertyIsLike>";

109         }

110         return result;

111     }

112 

113     private String formatPoint(String xml,String keyWord)

114     {

115         try

116         {

117             Document doc = DocumentHelper.parseText(xml);

118             

119             Element root = doc.getRootElement();

120             

121             Element newRoot = DocumentHelper.createElement("root");

122             newRoot.addAttribute("keyword", keyWord);

123         

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

125             

126             for (Element e : list)

127             {

128                 Element point = newRoot.addElement("point");

129                 Element xs = e.element("Poi").element("X");

130                 Element ys = e.element("Poi").element("Y");

131                 if (xs != null&&ys!=null)

132                 {

133                     String text=xs.getText()+","+ys.getText();

134                     point.addElement("xys").setText(text);

135                     point.addElement("type").setText("point");

136                     //point.addElement("x").setText(xs.getText());

137                     //point.addElement("y").setText(ys.getText());

138                 }

139                 point.addElement("name").setText(

140                         e.element("Poi").element("POI_NAME").getText());

141                 point.addElement("address").setText(

142                         e.element("Poi").element("ADDRESS").getText());

143             }

144             return newRoot.asXML();

145             // throw new Exception("formatPoint is fail");

146         }

147         catch (DocumentException e)

148         {

149             // TODO Auto-generated catch block

150             System.out.println("格式化失败！");

151             e.printStackTrace();

152         }

153 

154         return null;

155     }

156 

157     

158 }

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……