检查当前网络状态工具类

/**
 * @Description:检查当前网络状态
 * @Author:chen
 */
public class NetStatusUtil {

    /**
     * 检测当前打开的网络类型是否WIFI
     *
     * @param context 上下文
     * @return 是否是Wifi上网
     */
    public static boolean isWifi(Context context) {
        ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context
                .CONNECTIVITY_SERVICE);
        NetworkInfo activeNetInfo = connectivityManager.getActiveNetworkInfo();
        return activeNetInfo != null && activeNetInfo.getType() == ConnectivityManager.TYPE_WIFI;
    }

    /**
     * 是否有网
     */
    public static boolean isConnected(Context context) {
        return netStatus(context) != NetState.NET_NO;
    }

    /**
     * 枚举网络状态 NET_NO：没有网络 NET_2G:2g网络 NET_3G：3g网络 NET_4G：4g网络 NET_WIFI：wifi
     * NET_UNKNOWN：未知网络
     */
    public enum NetState {
        //没有网络
        NET_NO,
        //2g
        NET_2G,
        //3g
        NET_3G,
        //4g
        NET_4G,
        //wifi
        NET_WIFI,
        //未知网络
        NET_UNKNOWN
    }

    /**
     * 判断当前是否网络连接
     *
     * @param context 上下文
     * @return 状态码
     */
    public static NetState netStatus(Context context) {
        NetState stateCode = NetState.NET_NO;
        ConnectivityManager cm = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo ni = cm.getActiveNetworkInfo();
        if (ni != null && ni.isConnectedOrConnecting()) {
            switch (ni.getType()) {
                case ConnectivityManager.TYPE_WIFI:
                    stateCode = NetState.NET_WIFI;
                    break;
                case ConnectivityManager.TYPE_MOBILE:
                    switch (ni.getSubtype()) {
                        // 联通2g 电信2g 移动2g
                        case TelephonyManager.NETWORK_TYPE_GPRS:
                        case TelephonyManager.NETWORK_TYPE_CDMA:
                        case TelephonyManager.NETWORK_TYPE_EDGE:
                        case TelephonyManager.NETWORK_TYPE_1xRTT:
                        case TelephonyManager.NETWORK_TYPE_IDEN:
                            stateCode = NetState.NET_2G;
                            break;
                        // 电信3g
                        case TelephonyManager.NETWORK_TYPE_EVDO_A:
                        case TelephonyManager.NETWORK_TYPE_UMTS:
                        case TelephonyManager.NETWORK_TYPE_EVDO_0:
                        case TelephonyManager.NETWORK_TYPE_HSDPA:
                        case TelephonyManager.NETWORK_TYPE_HSUPA:
                        case TelephonyManager.NETWORK_TYPE_HSPA:
                        case TelephonyManager.NETWORK_TYPE_EVDO_B:
                        case TelephonyManager.NETWORK_TYPE_EHRPD:
                        case TelephonyManager.NETWORK_TYPE_HSPAP:
                            stateCode = NetState.NET_3G;
                            break;
                        case TelephonyManager.NETWORK_TYPE_LTE:
                            stateCode = NetState.NET_4G;
                            break;
                        default:
                            stateCode = NetState.NET_UNKNOWN;
                    }
                    break;
                default:
                    stateCode = NetState.NET_UNKNOWN;
            }

        }
        return stateCode;
    }
}