一个servlet实现GPS坐标偏移接口功能

这两天写了一个servlet，用于实现GPS坐标偏移接口功能。大概就是，我需要首先接收一个经纬度串数组，然后用json解析，给URL服务发送请求，服务器返回json格式的数组.

1 需要引入json-simple-1.1的类库。

2 web.xml配置

<?xml version="1.0" encoding="UTF-8"?><web-app version="2.5"  xmlns="http://java.sun.com/xml/ns/javaee"  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"  xsi:schemaLocation="http://java.sun.com/xml/ns/javaee  http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd">       <welcome-file-list>         <welcome-file>index.jsp</welcome-file>    </welcome-file-list>     <servlet>    <servlet-name>GPSConventCoordinateServlet</servlet-name>    <servlet-class>com.tm.gpsController.GPSConventCoordinateServlet</servlet-class>  </servlet>   <servlet-mapping>    <servlet-name>GPSConventCoordinateServlet</servlet-name>    <url-pattern>/GPSConventCoordinateServlet</url-pattern>  </servlet-mapping>    </web-app>

3 参照GPS坐标偏移接口文档，具体servlet代码如下：

package com.tm.gpsController;import java.io.BufferedOutputStream;import java.io.BufferedReader;import java.io.IOException;import java.io.InputStreamReader;import java.io.OutputStreamWriter;import java.net.HttpURLConnection;import java.net.URL;import java.net.URLConnection;import javax.servlet.ServletException;import javax.servlet.http.HttpServlet;import javax.servlet.http.HttpServletRequest;import javax.servlet.http.HttpServletResponse;import org.json.simple.JSONArray;import org.json.simple.JSONObject;import org.json.simple.parser.JSONParser;import org.json.simple.parser.ParseException;public class GPSConventCoordinateServlet extends HttpServlet { private static final long serialVersionUID = 3018725984829044717L; protected void doGet(HttpServletRequest req, HttpServletResponse resp)   throws ServletException, IOException {  // 我申请的key  String a_k = "XXXXXX";  String coors = req.getParameter("lonLatStr");  JSONParser parser = new JSONParser();  Object obj = "";  try {   obj = parser.parse(coors);  } catch (ParseException e) {   e.printStackTrace();  }  String lonLatStr = "";  JSONArray array = (JSONArray) obj;  for (Object j : array) {   //   lonLatStr = lonLatStr + ((JSONObject) j).get("lon") + ","     + ((JSONObject) j).get("lat") + ";";  }  lonLatStr = lonLatStr.substring(0, lonLatStr.length() - 1);  String postParam = "config=RGC&flag=true&resType=json&cr=0&coors="    + lonLatStr + "&a_k=" + a_k;  System.out.println(postParam);  // 服务地址  String urlString = "XXXXXX";  URL url = new URL(urlString);  URLConnection urlc = url.openConnection();  HttpURLConnection httpConnection = (HttpURLConnection) urlc;  httpConnection.setRequestMethod("POST");  httpConnection.setDoInput(true);  httpConnection.setDoOutput(true);  httpConnection.connect();  OutputStreamWriter osw = new OutputStreamWriter(    new BufferedOutputStream(httpConnection.getOutputStream()));  osw.write(postParam);  osw.flush();  System.out.println();  osw.close();  BufferedReader br = new BufferedReader(new InputStreamReader(    httpConnection.getInputStream()));  String line;  StringBuffer sbuffB = new StringBuffer();  while ((line = br.readLine()) != null) {   sbuffB.append(line + "\n");   System.out.println(line);  }  br.close();  httpConnection.disconnect(); } @Override protected void doPost(HttpServletRequest req, HttpServletResponse resp)   throws ServletException, IOException {  doGet(req, resp); }}

 

4    启动tomcat，部署一下，运行。

5    在浏览器中输入

http://localhost:8080/gpsCoordinateConvent/GPSConventCoordinateServlet?lonLatStr=[{"lon":133.34,"lat":35.33},{"lon":134.33,"lat":34.33]进行测试。

6    在控制台输出返回的信息{"message":"ok","list":[{"gridcode":"873482645301","y":"582.5422219509549","x":"582.5422219509549"},{"gridcode":"873482645301","y":"582.5422219509549","x":"582.5422219509549"}]}　就对了。

 

注意　在浏览器中输入的参数lonLatStr=[{"lon":133.34,"lat":35.33},{"lon":134.33,"lat":34.33]　参数格式有时候输入的特殊，服务器端就会返回一个默认的返回的结果。"[{"gridcode":"873482645301","y":"582.5422219509549","x":"582.5422219509549"}，这时候，其实程序是没有问题的，只需要改一下参数，就可以了。