获取IP的地理位置

最近写一个博客，获取IP的地理位置。查看了几个博客感觉比较复杂，下面是自己实现的一个：

package com.mo.util;

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.URL;
import java.net.URLConnection;
import java.util.Map;

import com.alibaba.fastjson.JSON;

public class IpAddress {

  /**
   * 传人一个ip返回一个地理位置
   * @param ip
   * @return
   */
  public static String changeIpToAddress(String ip) {
    Map<String, String> map = changeJsonToMap(getAddressByIp(ip));
    String country = revert(map.get("country"));
    String province = revert(map.get("province"));
    String city = revert(map.get("city"));
    return country + " " + province + "省 " + city + "市";
  }
  
  /**
   * 传人一个ip返回一个地理位置(只有省市)
   * @param ip
   * @return
   */
  public static String changeIpToAddressOnlyProAndCity(String ip) {
    Map<String, String> map = changeJsonToMap(getAddressByIp(ip));
    String province = revert(map.get("province"));
    String city = revert(map.get("city"));
    return province + " " + city;
  }
  
  /**
   * 传人ip地址，出来的是unicode编码的json数据
   * @return json字符串
   * @throws IOException
   */
  private static String getAddressByIp(String ip) {
    StringBuffer result;
    try {
      URL url = new URL("http://int.dpool.sina.com.cn/iplookup/iplookup.php?format=json&ip=" + ip);
      URLConnection conn = url.openConnection();
      BufferedReader reader = new BufferedReader(new InputStreamReader(conn.getInputStream(),"UTF-8"));
      String line = null;
      result = new StringBuffer();
      while((line = reader.readLine()) != null) {
        result.append(line);
      } 
      reader.close();
      return result.toString();
    } catch (IOException e) {
      System.out.println("ip没有找到");
    }
    return "无法找到ip地址";
  }


  /**
   * 将传人的JSON字符串封装为Map
   * @param json字符串
   * @return 封装了map的json的数据
   */
  private static Map<String, String> changeJsonToMap(String address) {
    Map maps = (Map)JSON.parse(address);  
    return maps;
  }

  /**
   * 将unicode转换为文字
   * @param 传人一个unicode编码
   * @return 返回一个汉字
   */
  private static String revert(String str) 
  { 
    str = (str == null ? "" : str); 
    if (str.indexOf("\\u") == -1)//如果不是unicode码则原样返回 
      return str; 

    StringBuffer sb = new StringBuffer(1000); 

    for (int i = 0; i < str.length() - 6;) 
    { 
      String strTemp = str.substring(i, i + 6); 
      String value = strTemp.substring(2); 
      int c = 0; 
      for (int j = 0; j < value.length(); j++) 
      { 
        char tempChar = value.charAt(j); 
        int t = 0; 
        switch (tempChar) 
        { 
        case 'a': 
          t = 10; 
          break; 
        case 'b': 
          t = 11; 
          break; 
        case 'c': 
          t = 12; 
          break; 
        case 'd': 
          t = 13; 
          break; 
        case 'e': 
          t = 14; 
          break; 
        case 'f': 
          t = 15; 
          break; 
        default: 
          t = tempChar - 48; 
          break; 
        } 

        c += t * ((int) Math.pow(16, (value.length() - j - 1))); 
      } 
      sb.append((char) c); 
      i = i + 6; 
    } 
    return sb.toString(); 
  }
}