如何在Android上获取本地网络中所有设备的IP地址和名称 [英] How to get IP address and names of all devices in local network on Android

问题描述

我想用java看到我网络上的所有连接设备，但是我无法使用它。我在下面附上了一些截图，说明我希望如何输出。我想要这个名字（例如TP Link Router或Nexus 5X）和IP地址。

I want to see all the connected devices on my network with java, but I can't get it working. I have attached some screenshots below of how I want it to be output. I would like to have the name (for example "TP Link Router" or "Nexus 5X") and the IP address.

我在google和stackoverflow上搜索了很多，但似乎没有什么对我有用。即使是GitHub也没有有效的代码。我尝试搜索UPnP，局域网，子网等，但一无所获。

I have searched a lot on google and stackoverflow, but nothing seemed to work for me. Even GitHub has no effective code. I tried searching for UPnP, Local Area Network, subnets, etc, but found nothing.

InetAddress localhost = InetAddress.getLocalHost();
byte[] ip = localhost.getAddress();
for (int i = 1; i <= 254; i++) {
    ip[3] = (byte)i;
    InetAddress address = InetAddress.getByAddress(ip);
    if (address.isReachable(1000)) {
        System.out.println(address + address.getHostAddress() + address.getAddress() + address.getHostName() + address.getCanonicalHostName());
    }
}

我确实发现了一个重复（某种）问题，但一年多来都没有回答。 来源

I did in fact find a duplicate (sort of) question, but it hasn't been answered for over a year. Source

推荐答案

主要问题是您正在抓取错误的IP地址。 InetAddress.getLocalHost（）返回127.0.0.1，这只是你的设备。

The main problem is that you're grabbing the wrong IP address. InetAddress.getLocalHost() is returning 127.0.0.1 and that's just your device.

改为使用Wifi IP地址：

Use the Wifi IP address in instead:

ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
WifiManager wm = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);

WifiInfo connectionInfo = wm.getConnectionInfo();
int ipAddress = connectionInfo.getIpAddress();
String ipString = Formatter.formatIpAddress(ipAddress);

这是一个快速而又脏的AsyncTask：

Here is a quick and dirty AsyncTask that does that:

static class NetworkSniffTask extends AsyncTask<Void, Void, Void> {

  private static final String TAG = Constants.TAG + "nstask";

  private WeakReference<Context> mContextRef;

  public NetworkSniffTask(Context context) {
    mContextRef = new WeakReference<Context>(context);
  }

  @Override
  protected Void doInBackground(Void... voids) {
    Log.d(TAG, "Let's sniff the network");

    try {
      Context context = mContextRef.get();

      if (context != null) {

        ConnectivityManager cm = (ConnectivityManager)context.getSystemService(Context.CONNECTIVITY_SERVICE);
        NetworkInfo activeNetwork = cm.getActiveNetworkInfo();
        WifiManager wm = (WifiManager)context.getSystemService(Context.WIFI_SERVICE);

        WifiInfo connectionInfo = wm.getConnectionInfo();
        int ipAddress = connectionInfo.getIpAddress();
        String ipString = Formatter.formatIpAddress(ipAddress);


        Log.d(TAG, "activeNetwork: " + String.valueOf(activeNetwork));
        Log.d(TAG, "ipString: " + String.valueOf(ipString));

        String prefix = ipString.substring(0, ipString.lastIndexOf(".") + 1);
        Log.d(TAG, "prefix: " + prefix);

        for (int i = 0; i < 255; i++) {
          String testIp = prefix + String.valueOf(i);

          InetAddress address = InetAddress.getByName(testIp);
          boolean reachable = address.isReachable(1000);
          String hostName = address.getCanonicalHostName();

          if (reachable)
            Log.i(TAG, "Host: " + String.valueOf(hostName) + "(" + String.valueOf(testIp) + ") is reachable!");
        }
      }
    } catch (Throwable t) {
      Log.e(TAG, "Well that's not good.", t);
    }

  return null;
}

以下是权限：

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

并非所有路由器都允许这样做，所以以其他方式获取名称就是发送mac地址到api并获得品牌名称作为回报。

Not all routers allow this, so to get the names in a other way is to send the mac adress to an api and get the brand name back in return.

String macAdress = "5caafd1b0019";
String dataUrl = "http://api.macvendors.com/" + macAdress;
HttpURLConnection connection = null;
try {
    URL url = new URL(dataUrl);
    connection = (HttpURLConnection) url.openConnection();
    connection.setRequestMethod("POST");
    connection.setRequestProperty("Content-Type", "application/x-www-form-urlencoded");
    connection.setDoInput(true);
    connection.setDoOutput(true);
    DataOutputStream wr = new DataOutputStream(connection.getOutputStream());
    wr.flush();
    wr.close();
    InputStream is = connection.getInputStream();
    BufferedReader rd = new BufferedReader(new InputStreamReader(is));
    StringBuffer response = new StringBuffer();
    String line;
    while ((line = rd.readLine()) != null) {response.append(line);response.append('\r');}
    rd.close();
    String responseStr = response.toString();
    Log.d("Server response", responseStr);
} catch (Exception e) {e.printStackTrace();} finally {if (connection != null) {connection.disconnect();}}

这篇关于如何在Android上获取本地网络中所有设备的IP地址和名称的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！