/**
     * 检测网络是否可用
     *
     * @return
     */
    public boolean isNetworkConnected() {
        ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo ni = cm.getActiveNetworkInfo();
        return ni != null && ni.isConnectedOrConnecting();
    }

    /**
     * 获取当前网络类型
     *
     * @return 0：没有网络 1：WIFI网络 2：WAP网络 3：NET网络
     */
    public int getNetworkType() {
        int netType = 0;
        ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo networkInfo = connectivityManager.getActiveNetworkInfo();
        if (networkInfo == null) {
            return netType;
        }
        int nType = networkInfo.getType();
        if (nType == ConnectivityManager.TYPE_MOBILE) {
            String extraInfo = networkInfo.getExtraInfo();
            if (!StringUtils.isEmpty(extraInfo)) {
                if (extraInfo.toLowerCase().equals("cmnet")) {
                    netType = NETTYPE_CMNET;
                } else {
                    netType = NETTYPE_CMWAP;
                }
            }
        } else if (nType == ConnectivityManager.TYPE_WIFI) {
            netType = NETTYPE_WIFI;
        }
        return netType;
    }

android 检测网络是否可用