如何在Android应用程序中使用3G连接而不是Wi-Fi？

Question

如何在Android应用程序中使用3G连接而不是Wi-Fi？

我想连接3G连接,是否有任何示例代码连接到3G而不是Wi-Fi？

Answer 1

/**
 * Enable mobile connection for a specific address
 * @param context a Context (application or activity)
 * @param address the address to enable
 * @return true for success, else false
 */
private boolean forceMobileConnectionForAddress(Context context, String address) {
    ConnectivityManager connectivityManager = (ConnectivityManager) context.getSystemService(Context.CONNECTIVITY_SERVICE);
    if (null == connectivityManager) {
        Log.debug(TAG_LOG, "ConnectivityManager is null, cannot try to force a mobile connection");
        return false;
    }

    //check if mobile connection is available and connected
    State state = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE_HIPRI).getState();
    Log.debug(TAG_LOG, "TYPE_MOBILE_HIPRI network state: " + state);
    if (0 == state.compareTo(State.CONNECTED) || 0 == state.compareTo(State.CONNECTING)) {
        return true;
    }

    //activate mobile connection in addition to other connection already activated
    int resultInt = connectivityManager.startUsingNetworkFeature(ConnectivityManager.TYPE_MOBILE, "enableHIPRI");
    Log.debug(TAG_LOG, "startUsingNetworkFeature for enableHIPRI result: " + resultInt);

    //-1 means errors
    // 0 means already enabled
    // 1 means enabled
    // other values can be returned, because this method is vendor specific
    if (-1 == resultInt) {
        Log.error(TAG_LOG, "Wrong result of startUsingNetworkFeature, maybe problems");
        return false;
    }
    if (0 == resultInt) {
        Log.debug(TAG_LOG, "No need to perform additional network settings");
        return true;
    }

    //find the host name to route
    String hostName = StringUtil.extractAddressFromUrl(address);
    Log.debug(TAG_LOG, "Source address: " + address);
    Log.debug(TAG_LOG, "Destination host address to route: " + hostName);
    if (TextUtils.isEmpty(hostName)) hostName = address;

    //create a route for the specified address
    int hostAddress = lookupHost(hostName);
    if (-1 == hostAddress) {
        Log.error(TAG_LOG, "Wrong host address transformation, result was -1");
        return false;
    }
    //wait some time needed to connection manager for waking up
    try {
        for (int counter=0; counter<30; counter++) {
            State checkState = connectivityManager.getNetworkInfo(ConnectivityManager.TYPE_MOBILE_HIPRI).getState();
            if (0 == checkState.compareTo(State.CONNECTED))
                break;
            Thread.sleep(1000);
        }
    } catch (InterruptedException e) {
        //nothing to do
    }
    boolean resultBool = connectivityManager.requestRouteToHost(ConnectivityManager.TYPE_MOBILE_HIPRI, hostAddress);
    Log.debug(TAG_LOG, "requestRouteToHost result: " + resultBool);
    if (!resultBool)
        Log.error(TAG_LOG, "Wrong requestRouteToHost result: expected true, but was false");

    return resultBool;
}

这用于计算主机地址:

/**
 * This method extracts from address the hostname
 * @param url eg. http://some.where.com:8080/sync
 * @return some.where.com
 */
public static String extractAddressFromUrl(String url) {
    String urlToProcess = null;

    //find protocol
    int protocolEndIndex = url.indexOf("://");
    if(protocolEndIndex>0) {
        urlToProcess = url.substring(protocolEndIndex + 3);
    } else {
        urlToProcess = url;
    }

    // If we have port number in the address we strip everything
    // after the port number
    int pos = urlToProcess.indexOf(':');
    if (pos >= 0) {
        urlToProcess = urlToProcess.substring(0, pos);
    }

    // If we have resource location in the address then we strip
    // everything after the '/'
    pos = urlToProcess.indexOf('/');
    if (pos >= 0) {
        urlToProcess = urlToProcess.substring(0, pos);
    }

    // If we have ? in the address then we strip
    // everything after the '?'
    pos = urlToProcess.indexOf('?');
    if (pos >= 0) {
        urlToProcess = urlToProcess.substring(0, pos);
    }
    return urlToProcess;
}

/**
 * Transform host name in int value used by {@link ConnectivityManager.requestRouteToHost}
 * method
 *
 * @param hostname
 * @return -1 if the host doesn't exists, elsewhere its translation
 * to an integer
 */
private static int lookupHost(String hostname) {
    InetAddress inetAddress;
    try {
        inetAddress = InetAddress.getByName(hostname);
    } catch (UnknownHostException e) {
        return -1;
    }
    byte[] addrBytes;
    int addr;
    addrBytes = inetAddress.getAddress();
    addr = ((addrBytes[3] & 0xff) << 24)
            | ((addrBytes[2] & 0xff) << 16)
            | ((addrBytes[1] & 0xff) << 8 )
            |  (addrBytes[0] & 0xff);
    return addr;
}

并且必须将以下权限添加到AndroidManifest.xml

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

它仅适用于Android 2.2及更高版本,在Nexus One和LG Optimus上测试,其他手机我不知道,因为ConnectivityMananger的某些方法是特定于供应商的.在15-20秒不活动后,移动网络将自动断开连接.

Answer 2

T-Mobile"我的帐户"应用程序执行此操作,如果您连接到WiFi连接,它会告诉您他们的程序无法通过WiFi工作,然后询问用户是否要关闭WiFi连接.如果您选择"没有"然后应用程序退出,如果您选择"是",则应用程序将关闭您的WiFi连接,然后继续启动.

我认为这是一个很好的模型,它将确保您的应用程序不通过WiFi运行,并允许用户决定是否要关闭WiFi.这种模式的改进是当用户离开你的应用程序时重新打开wifi.

我没有测试过以下代码,但它看起来应该可以工作(从这里修改)

在清单中使用以下权限

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

这里有一些实际的代码来打开/关闭wifi

private WifiManager wifiManager;

@Override 
public void onCreate(Bundle icicle)
{
    ....................

    wifiManager = (WifiManager) this.getSystemService(Context.WIFI_SERVICE);

    if(wifiManager.isWifiEnabled())
    {
        wifiManager.setWifiEnabled(false);
    }
    else
    {
        wifiManager.setWifiEnabled(true);
    }
}

如果您不想沿着这条路走下去,看起来您可能会告诉手机您更愿意使用移动数据网络而不是wifi网络.

Android ConnectivityManager提供了一个功能setNetworkPreference.如果您单击该链接,则无法记录此功能.我会讨论它,因为定义的常量似乎暗示你可以将它设置为TYPE_MOBILE或TYPE_WIFI,并且还有一个DEFAULT_NETWORK_PREFERENCE常量定义为0x00000001,它与TYPE_WIFI相同.因此,请尝试通过调用访问ConnectivityManager

Context.getSystemService(Context.CONNECTIVITY_SERVICE);

然后尝试使用setNetworkPreference()函数.

它似乎不需要清单中的任何权限,但它可能需要CHANGE_NETWORK_STATE权限或沿着这些行.

如果您使用setNetworkPreference函数,最好也将网络首选项设置回其原始值(从getNetworkPreference接收)

我希望这有帮助.

Answer 3

我认为这不可能来自Java.如果连接到无线网络,系统将关闭所有基于移动网络的通信.我认为您不能从您的程序启动3G连接.

Answer 4

这是适用于 API 21+（棒棒糖、棉花糖 ..）的代码。我更喜欢将 OkHttp 与Network.getSocketFactory()一起使用，但Network.openURLConnection()也可以正常工作。

private void doTest()
{
    display("Requesting CELLULAR network connectivity...");
    ConnectivityManager connectivityManager = (ConnectivityManager) getSystemService(CONNECTIVITY_SERVICE);

    NetworkRequest request = new NetworkRequest.Builder()
            .addTransportType(NetworkCapabilities.TRANSPORT_CELLULAR)
            .addCapability(NetworkCapabilities.NET_CAPABILITY_INTERNET).build();

    connectivityManager.requestNetwork(request, new ConnectivityManager.NetworkCallback()
    {
        /**
         * Called when the framework connects and has declared a new network ready for use.
         * This callback may be called more than once if the {@link Network} that is
         * satisfying the request changes.
         *
         * This method will be called on non-UI thread, so beware not to use any UI updates directly.
         *
         * @param network The {@link Network} of the satisfying network.
         */
        @Override
        public void onAvailable(final Network network)
        {
            display("Got available network: " + network.toString());

            try
            {
                final InetAddress address = network.getByName("navalclash.com");
                display("Resolved host2ip: " + address.getHostName() + " -> " +  address.getHostAddress());
            }
            catch (UnknownHostException e)
            {
                e.printStackTrace();
            }

            display("Do request test page from remote http server...");

            if(okHttpClient == null)
            {
                okHttpClient = new OkHttpClient.Builder().socketFactory(network.getSocketFactory()).build();
            }

            Request request = new Request.Builder()
                    .url("http://navalclash.com")
                    .build();
            try (Response response = okHttpClient.newCall(request).execute())
            {
                display("RESULT:\n" + response.body().string());
            }
            catch (Exception ex)
            {
                ex.printStackTrace();
            }
        }
    });
}