Android 获取网络链接类型

	/**
	 * 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;
	}