Android 跟網絡連接相關的工具類

public class NetUtils {
    private NetUtils() {
        /** cannot be instantiated **/
        throw new UnsupportedOperationException("cannot be instantiated");
    }

    /**
     * 判斷網絡是否連接
     *
     * @param context
     * @return
     */

    public static boolean isConnected(Context context) {

        ConnectivityManager connectivity = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        if (null != connectivity) {

            NetworkInfo info = connectivity.getActiveNetworkInfo();
            if (null != info && info.isConnected()) {
                if (info.getState() == NetworkInfo.State.CONNECTED) {
                    return true;
                }
            }
        }
        return false;
    }

    /**
     * 判斷是否是wifi連接
     */

    public static boolean isWifi(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);

        if (cm == null)
            return false;
        return cm.getActiveNetworkInfo().getType() == ConnectivityManager.TYPE_WIFI;

    }

    /**
     * 打開網絡設置界面
     */

    public static void openSetting(Activity activity) {
        Intent intent = new Intent("/");
        ComponentName cm = new ComponentName("com.android.settings",
                "com.android.settings.WirelessSettings");
        intent.setComponent(cm);
        intent.setAction("android.intent.action.VIEW");
        activity.startActivityForResult(intent, 0);
    }

}