/**
     * 获取当前的网络状态 ：没有网络-0：WIFI网络1：4G网络-4：3G网络-3：2G网络-2
     * 自定义
     *
     * @param context
     * @return
     */
    public static int getAPNType(Context context) {
        //结果返回值
        int netType = 0;
        //获取手机所有连接管理对象
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        //获取NetworkInfo对象
        NetworkInfo networkInfo = manager.getActiveNetworkInfo();
        //NetworkInfo对象为空 则代表没有网络
        if (networkInfo == null) {
            return netType;
        }
        //否则 NetworkInfo对象不为空 则获取该networkInfo的类型
        int nType = networkInfo.getType();
        if (nType == ConnectivityManager.TYPE_WIFI) {
            //WIFI
            netType = 1;
        } else if (nType == ConnectivityManager.TYPE_MOBILE) {
            int nSubType = networkInfo.getSubtype();
            TelephonyManager telephonyManager = (TelephonyManager) context.getSystemService(Context.TELEPHONY_SERVICE);
            //3G   联通的3G为UMTS或HSDPA 电信的3G为EVDO
            if (nSubType == TelephonyManager.NETWORK_TYPE_LTE
                    && !telephonyManager.isNetworkRoaming()) {
                netType = 4;
            } else if (nSubType == TelephonyManager.NETWORK_TYPE_UMTS
                    || nSubType == TelephonyManager.NETWORK_TYPE_HSDPA
                    || nSubType == TelephonyManager.NETWORK_TYPE_EVDO_0
                    && !telephonyManager.isNetworkRoaming()) {
                netType = 3;
                //2G 移动和联通的2G为GPRS或EGDE，电信的2G为CDMA
            } else if (nSubType == TelephonyManager.NETWORK_TYPE_GPRS
                    || nSubType == TelephonyManager.NETWORK_TYPE_EDGE
                    || nSubType == TelephonyManager.NETWORK_TYPE_CDMA
                    && !telephonyManager.isNetworkRoaming()) {
                netType = 2;
            } else {
                netType = 2;
            }
        }
        return netType;
    }

/* 
 * @category 判断是否有外网连接（普通方法不能判断外网的网络是否连接，比如连接上局域网）
 * @return
 */ 
public static final boolean ping() { 
  String result = null; 
  try { 
      String ip = "www.baidu.com";// ping 的地址，可以换成任何一种可靠的外网 
      Process p = Runtime.getRuntime().exec("ping -c 3 -w 100 " + ip);// ping网址3次 
      // 读取ping的内容，可以不加 
      InputStream input = p.getInputStream(); 
      BufferedReader in = new BufferedReader(new InputStreamReader(input)); 
      StringBuffer stringBuffer = new StringBuffer(); 
      String content = ""; 
      while ((content = in.readLine()) != null) { 
          stringBuffer.append(content); 
      } 
      Log.d("------ping-----", "result content : " + stringBuffer.toString()); 
      // ping的状态 
      int status = p.waitFor(); 
      if (status == 0) { 
          result = "success"; 
          return true; 
      } else { 
          result = "failed"; 
      } 
  } catch (IOException e) { 
      result = "IOException"; 
  } catch (InterruptedException e) { 
      result = "InterruptedException"; 
  } finally { 
      Log.d("----result---", "result = " + result); 
  } 
  return false;
}