java - isReachable()在Android中返回false

好吧，当我的手机作为热点工作时，我需要检测所有与手机连接的设备并找到其MAC地址。我写了这样的东西：

public void getListOfConnectedDevice() {
    Thread thread = new Thread(new Runnable() {

        @Override
        public void run() {
            BufferedReader br = null;
            boolean isFirstLine = true;

            try {
                br = new BufferedReader(new FileReader("/proc/net/arp"));
                String line;

                while ((line = br.readLine()) != null) {
                    if (isFirstLine) {
                        isFirstLine = false;
                        continue;
                    }

                    String[] splitted = line.split(" +");

                    if (splitted != null && splitted.length >= 4) {

                        String ipAddress = splitted[0];
                        String macAddress = splitted[3];

                       boolean isReachable = InetAddress.getByName(
                                splitted[0]).isReachable(300);// this is network call so we cant do that on UI thread, so i take background thread.
                        Log.d(TAG, "ip: " + splitted[0]);
                        Log.d(TAG, "isReachable: " + isReachable);
                        if (isReachable) {
                            Log.d("Device Information", ipAddress + " : "
                                    + macAddress);
                            macAddresses.add(macAddress); //My List<String>
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    });
    thread.start();
}

但是boolean isReachable = InetAddress.getByName( splitted[0]).isReachable(300);仅在连接或断开设备时返回false。而且我找不到任何信息来查找解决方案。还是有其他解决方案？ （适用于没有根目录的电话）。

最佳答案

好吧，我发现android将设备的MAC地址保留了大约10分钟（在不同的设备上-不同的时间），这是唯一的方法-使用ADB shell命令清除该列表，但是！它仅适用于有根设备。

但是此代码可以为您提供帮助（不适用于所有设备）：

public void getListOfConnectedDevice() {
    final Thread thread = new Thread(new Runnable() {

        @Override
        public void run() {
            macAddresses.clear();
            BufferedReader br = null;
            boolean isFirstLine = true;
            try {

                br = new BufferedReader(new FileReader("/proc/net/arp"));
                String line;

                while ((line = br.readLine()) != null) {
                    if (isFirstLine) {
                        isFirstLine = false;
                        continue;
                    }

                    String[] splitted = line.split(" +");

                    if (splitted != null && splitted.length >= 4) {

                        String ipAddress = splitted[0];
                        String macAddress = splitted[3];

                        Node node = new Node(ipAddress, macAddress);
                        boolean isReachable = node.isReachable;
                        Log.d(TAG, "isReachable: " + isReachable);
                        if (isReachable) {
                            Log.d("Device Information", ipAddress + " : "
                                    + macAddress);
                            macAddresses.add(macAddress);
                        }
                    }
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                try {
                    br.close();
                } catch (IOException e) {
                    e.printStackTrace();
                }
            }
        }
    });
    thread.start();
}