判断安卓设备是否连接网络

当一个程序需要联网进行请求数据时， 如何判断一个设备是否连接网络？

<span style="font-size:24px;">/** * 判断设备是否连接网络 * @return */public boolean isConnectedNet() {ConnectivityManager con = (ConnectivityManager) getSystemService(Activity.CONNECTIVITY_SERVICE);boolean wifi = con.getNetworkInfo(ConnectivityManager.TYPE_WIFI).isConnectedOrConnecting();boolean internet = false;if (con.getNetworkInfo(ConnectivityManager.TYPE_MOBILE) != null) {internet = con.getNetworkInfo(ConnectivityManager.TYPE_MOBILE).isConnectedOrConnecting();}return wifi | internet;}</span>