Android
インターネット接続を確認する

前書き

構文

• isNetworkAvailable（）：デバイスでインターネットが利用可能かどうかを確認する

パラメーター

備考

デバイスにインターネット接続があるかどうかを確認する

アプリケーションマニフェストファイルに必要なネットワークアクセス許可を追加します。

<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />

/**
 * If network connectivity is available, will return true
 *
 * @param context the current context
 * @return boolean true if a network connection is available
 */
public static boolean isNetworkAvailable(Context context) {
    ConnectivityManager connectivity = (ConnectivityManager) context
            .getSystemService(Context.CONNECTIVITY_SERVICE);
    if (connectivity == null) {
        Log.d("NetworkCheck", "isNetworkAvailable: No");
        return false;
    }

    // get network info for all of the data interfaces (e.g. WiFi, 3G, LTE, etc.)
    NetworkInfo[] info = connectivity.getAllNetworkInfo();

    // make sure that there is at least one interface to test against
    if (info != null) {
        // iterate through the interfaces
        for (int i = 0; i < info.length; i++) {
            // check this interface for a connected state
            if (info[i].getState() == NetworkInfo.State.CONNECTED) {
                Log.d("NetworkCheck", "isNetworkAvailable: Yes");
                return true;
            }
        }
    }
    return false;
}

どのようにアンドロイドでネットワークの強さを確認するには？

        ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo Info = cm.getActiveNetworkInfo();
        if (Info == null || !Info.isConnectedOrConnecting()) {
            Log.i(TAG, "No connection");
        } else {
            int netType = Info.getType();
            int netSubtype = Info.getSubtype();

            if (netType == ConnectivityManager.TYPE_WIFI) {
                Log.i(TAG, "Wifi connection");
                WifiManager wifiManager = (WifiManager) getApplication().getSystemService(Context.WIFI_SERVICE);
                List<ScanResult> scanResult = wifiManager.getScanResults();
                for (int i = 0; i < scanResult.size(); i++) {
                    Log.d("scanResult", "Speed of wifi"+scanResult.get(i).level);//The db level of signal 
                }
                
                
                // Need to get wifi strength
            } else if (netType == ConnectivityManager.TYPE_MOBILE) {
                Log.i(TAG, "GPRS/3G connection");
                // Need to get differentiate between 3G/GPRS
            }
        }

ネットワークの強さをチェックする方法

正確な強度をデシベル単位で確認するには、

ConnectivityManager cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
    NetworkInfo Info = cm.getActiveNetworkInfo();
    if (Info == null || !Info.isConnectedOrConnecting()) {
        Log.i(TAG, "No connection");
    } else {
        int netType = Info.getType();
        int netSubtype = Info.getSubtype();

        if (netType == ConnectivityManager.TYPE_WIFI) {
            Log.i(TAG, "Wifi connection");
            WifiManager wifiManager = (WifiManager) getApplication().getSystemService(Context.WIFI_SERVICE);
            List<ScanResult> scanResult = wifiManager.getScanResults();
            for (int i = 0; i < scanResult.size(); i++) {
                Log.d("scanResult", "Speed of wifi"+scanResult.get(i).level);//The db level of signal 
            }


            // Need to get wifi strength
        } else if (netType == ConnectivityManager.TYPE_MOBILE) {
            Log.i(TAG, "GPRS/3G connection");
            // Need to get differentiate between 3G/GPRS
        }
    }

ネットワークタイプをチェックするには、このClass-

 public class Connectivity {
        /*
         * These constants aren't yet available in my API level (7), but I need to
         * handle these cases if they come up, on newer versions
         */
        public static final int NETWORK_TYPE_EHRPD = 14; // Level 11
        public static final int NETWORK_TYPE_EVDO_B = 12; // Level 9
        public static final int NETWORK_TYPE_HSPAP = 15; // Level 13
        public static final int NETWORK_TYPE_IDEN = 11; // Level 8
        public static final int NETWORK_TYPE_LTE = 13; // Level 11

    /**
     * Check if there is any connectivity
     * 
     * @param context
     * @return
     */
    public static boolean isConnected(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = cm.getActiveNetworkInfo();
        return (info != null && info.isConnected());
    }

    /**
     * Check if there is fast connectivity
     * 
     * @param context
     * @return
     */
    public static String isConnectedFast(Context context) {
        ConnectivityManager cm = (ConnectivityManager) context
                .getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo info = cm.getActiveNetworkInfo();

        if ((info != null && info.isConnected())) {
            return Connectivity.isConnectionFast(info.getType(),
                    info.getSubtype());
        } else
            return "No NetWork Access";

    }

    /**
     * Check if the connection is fast
     * 
     * @param type
     * @param subType
     * @return
     */
    public static String isConnectionFast(int type, int subType) {
        if (type == ConnectivityManager.TYPE_WIFI) {
            System.out.println("CONNECTED VIA WIFI");
            return "CONNECTED VIA WIFI";
        } else if (type == ConnectivityManager.TYPE_MOBILE) {
            switch (subType) {
            case TelephonyManager.NETWORK_TYPE_1xRTT:
                return "NETWORK TYPE 1xRTT"; // ~ 50-100 kbps
            case TelephonyManager.NETWORK_TYPE_CDMA:
                return "NETWORK TYPE CDMA (3G) Speed: 2 Mbps"; // ~ 14-64 kbps
            case TelephonyManager.NETWORK_TYPE_EDGE:

                return "NETWORK TYPE EDGE (2.75G) Speed: 100-120 Kbps"; // ~
                                                                        // 50-100
                                                                        // kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_0:
                return "NETWORK TYPE EVDO_0"; // ~ 400-1000 kbps
            case TelephonyManager.NETWORK_TYPE_EVDO_A:
                return "NETWORK TYPE EVDO_A"; // ~ 600-1400 kbps
            case TelephonyManager.NETWORK_TYPE_GPRS:
                return "NETWORK TYPE GPRS (2.5G) Speed: 40-50 Kbps"; // ~ 100
                                                                        // kbps
            case TelephonyManager.NETWORK_TYPE_HSDPA:
                return "NETWORK TYPE HSDPA (4G) Speed: 2-14 Mbps"; // ~ 2-14
                                                                    // Mbps
            case TelephonyManager.NETWORK_TYPE_HSPA:
                return "NETWORK TYPE HSPA (4G) Speed: 0.7-1.7 Mbps"; // ~
                                                                        // 700-1700
                                                                        // kbps
            case TelephonyManager.NETWORK_TYPE_HSUPA:
                return "NETWORK TYPE HSUPA (3G) Speed: 1-23 Mbps"; // ~ 1-23
                                                                    // Mbps
            case TelephonyManager.NETWORK_TYPE_UMTS:
                return "NETWORK TYPE UMTS (3G) Speed: 0.4-7 Mbps"; // ~ 400-7000
                                                                    // kbps
                // NOT AVAILABLE YET IN API LEVEL 7
            case Connectivity.NETWORK_TYPE_EHRPD:
                return "NETWORK TYPE EHRPD"; // ~ 1-2 Mbps
            case Connectivity.NETWORK_TYPE_EVDO_B:
                return "NETWORK_TYPE_EVDO_B"; // ~ 5 Mbps
            case Connectivity.NETWORK_TYPE_HSPAP:
                return "NETWORK TYPE HSPA+ (4G) Speed: 10-20 Mbps"; // ~ 10-20
                                                                    // Mbps
            case Connectivity.NETWORK_TYPE_IDEN:
                return "NETWORK TYPE IDEN"; // ~25 kbps
            case Connectivity.NETWORK_TYPE_LTE:
                return "NETWORK TYPE LTE (4G) Speed: 10+ Mbps"; // ~ 10+ Mbps
                // Unknown
            case TelephonyManager.NETWORK_TYPE_UNKNOWN:
                return "NETWORK TYPE UNKNOWN";
            default:
                return "";
            }
        } else {
            return "";
        }
    }

}