Spring MVC+JQuery+Google Map打造IP位置查找应用

在本文中，读者将学习到如何使用Spring MVC框架和jQuery及Google Map,制作一个简单的根据IP位置查找应用。用户可以在页面中输入一个IP地址，然后通过Google Map显示该IP所在的大概地理位置.

我们将用到如下技术：

1. Spring MVC frameworks
2. jQuery(Ajax Request)
3. GeoLite 数据库
4. Google Map

5. 其中用户的操作步骤如下：

   1. 用户输入IP地址,然后点提交按钮
   2. jQuery发出Ajax请求到Spring MVC中的控制器
   3. 在Spring MVC控制器中处理并返回JSON格式数据
   4. jQuery处理返回的json数据并通过Google Map展示给用户

      Spring MVC+Geo Lite

      下面首先编写根据IP查找地理位置的接口,命名为ServerLocationBo.java,代码为：

      package com.mkyong.web.location;
      
      ublic interface ServerLocationBo {
      
      ServerLocation getLocation(String ipAddress);

      其实现类的代码为：

      package com.mkyong.web.location;
      
      import java.io.IOException;
      import java.net.URL;
      import org.springframework.stereotype.Component;
      import com.maxmind.geoip.Location;
      import com.maxmind.geoip.LookupService;
      import com.maxmind.geoip.regionName;
      
      @Component
      public class ServerLocationBoImpl implements ServerLocationBo {
      
          @Override
          public ServerLocation getLocation(String ipAddress) {
      
              String dataFile = "location/GeoLiteCity.dat";
              return getLocation(ipAddress, dataFile);
      
          }
      
          private ServerLocation getLocation(String ipAddress, String locationDataFile) {
      
            ServerLocation serverLocation = null;
      
            URL url = getClass().getClassLoader().getResource(locationDataFile);
      
            if (url == null) {
              System.err.println("location database is not found - "
                  + locationDataFile);
            } else {
      
            try {
      
              serverLocation = new ServerLocation();
      
              LookupService lookup = new LookupService(url.getPath(),
                      LookupService.GEOIP_MEMORY_CACHE);
              Location locationServices = lookup.getLocation(ipAddress);
      
              serverLocation.setCountryCode(locationServices.countryCode);
              serverLocation.setCountryName(locationServices.countryName);
              serverLocation.setRegion(locationServices.region);
              serverLocation.setRegionName(regionName.regionNameByCode(
                  locationServices.countryCode, locationServices.region));
              serverLocation.setCity(locationServices.city);
              serverLocation.setPostalCode(locationServices.postalCode);
              serverLocation.setLatitude(
                                      String.valueOf(locationServices.latitude));
              serverLocation.setLongitude(
                                      String.valueOf(locationServices.longitude));
      
            } catch (IOException e) {
      
              System.err.println(e.getMessage());
      
            }
      
           }
      
           return serverLocation;
      
          }
      }

      在上面的这个方法中,在getLocations方法中,加载了GeoLite格式的IP地址库文件GeoLiteCity.dat,并且调用getLocation方法进行IP的查找,.在getLocation方法中,通过GeoLite创建一个LookupService类的实例，其中传入要查询的IP地址库文件，然后再调用其getLocation方法进行查询，这里查询出来的结果构造成serverLocation对象，下面来看下其serverlocation对象的代码：

      package com.mkyong.web.location;
      
      public class ServerLocation {
      
          private String countryCode;
          private String countryName;
          private String region;
          private String regionName;
          private String city;
          private String postalCode;
          private String latitude;
          private String longitude;
      
          //getter and setter methods
      
      }

      然后我们使用Spring MVC框架中的Jackson对结果进行转换，转换为json，代码如下：

      package com.mkyong.web.controller;
      
      import org.codehaus.jackson.map.ObjectMapper;
      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 org.springframework.web.bind.annotation.RequestParam;
      import org.springframework.web.bind.annotation.ResponseBody;
      import org.springframework.web.servlet.ModelAndView;
      
      import com.mkyong.web.location.ServerLocation;
      import com.mkyong.web.location.ServerLocationBo;
      
      @Controller
      public class MapController {
      
          @Autowired
          ServerLocationBo serverLocationBo;
      
          @RequestMapping(value = "/", method = RequestMethod.GET)
          public ModelAndView getPages() {
      
              ModelAndView model = new ModelAndView("map");
              return model;
      
          }
      
          //return back json string
          @RequestMapping(value = "/getLocationByIpAddress", method = RequestMethod.GET)
          public @ResponseBody
          String getDomainInJsonFormat(@RequestParam String ipAddress) {
      
              ObjectMapper mapper = new ObjectMapper();
      
              ServerLocation location = serverLocationBo.getLocation(ipAddress);
      
              String result = "";
      
              try {
                  result = mapper.writeValueAsString(location);
              } catch (Exception e) {
      
                  e.printStackTrace();
              }
      
              return result;
      
          }
      
      }