Wifi BSSID获取

代码很简单，通过wifiManager 获取wifiinfo，从而获取bssid，

  public static String getWifiSSID(Context context) {
        String bssid = "";
        ConnectivityManager manager = (ConnectivityManager) context.getSystemService(CONNECTIVITY_SERVICE);
        if (manager == null) {
            return bssid;
        }

        NetworkInfo activeNetworkInfo = manager.getActiveNetworkInfo();
        if (activeNetworkInfo != null && activeNetworkInfo.isConnectedOrConnecting() && activeNetworkInfo.getType() == TYPE_WIFI) {
            WifiManager wifiManager = (WifiManager) context.getApplicationContext().getSystemService(WIFI_SERVICE);
            if (wifiManager == null) {
                return bssid;
            }
            WifiInfo connectionInfo = wifiManager.getConnectionInfo();
            bssid = connectionInfo.getBSSID();
        }
        return bssid;
    }

几个注意的地方吧：

1：getActiveNetworkInfo方法时需要添加权限

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

2：直接通过上述方法执行时，会抛出RuntimeException：

  java.lang.RuntimeException: Unable to start activity ComponentInfo{com.zh.wifiinfotest/com.zh.wifiinfotest.MainActivity}: java.lang.SecurityException: WifiService: Neither user 10138 nor current process has android.permission.ACCESS_WIFI_STATE.
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3915)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4098)
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91)
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149)
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103)
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2475)
        at android.os.Handler.dispatchMessage(Handler.java:110)
        at android.os.Looper.loop(Looper.java:219)
        at android.app.ActivityThread.main(ActivityThread.java:8401)
        at java.lang.reflect.Method.invoke(Native Method)
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513)
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1087)
     Caused by: java.lang.SecurityException: WifiService: Neither user 10138 nor current process has android.permission.ACCESS_WIFI_STATE.
        at android.os.Parcel.createException(Parcel.java:2082)
        at android.os.Parcel.readException(Parcel.java:2050)
        at android.os.Parcel.readException(Parcel.java:1998)
        at android.net.wifi.IWifiManager$Stub$Proxy.getConnectionInfo(IWifiManager.java:2374)
        at android.net.wifi.WifiManager.getConnectionInfo(WifiManager.java:2338)
        at com.zh.wifiinfotest.MainActivity.getWifiSSID(MainActivity.java:39)
        at com.zh.wifiinfotest.MainActivity.onCreate(MainActivity.java:23)
        at android.app.Activity.performCreate(Activity.java:8121)
        at android.app.Activity.performCreate(Activity.java:8109)
        at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1320)
        at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3888)
        at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:4098) 
        at android.app.servertransaction.LaunchActivityItem.execute(LaunchActivityItem.java:91) 
        at android.app.servertransaction.TransactionExecutor.executeCallbacks(TransactionExecutor.java:149) 
        at android.app.servertransaction.TransactionExecutor.execute(TransactionExecutor.java:103) 
        at android.app.ActivityThread$H.handleMessage(ActivityThread.java:2475) 
        at android.os.Handler.dispatchMessage(Handler.java:110) 
        at android.os.Looper.loop(Looper.java:219) 
        at android.app.ActivityThread.main(ActivityThread.java:8401) 
        at java.lang.reflect.Method.invoke(Native Method) 
        at com.android.internal.os.RuntimeInit$MethodAndArgsCaller.run(RuntimeInit.java:513) 
        at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1087) 
     Caused by: android.os.RemoteException: Remote stack trace:
        at android.app.ContextImpl.enforce(ContextImpl.java:2025)
        at android.app.ContextImpl.enforceCallingOrSelfPermission(ContextImpl.java:2053)
        at com.android.server.wifi.WifiServiceImpl.enforceAccessPermission(WifiServiceImpl.java:1130)
        at com.android.server.wifi.WifiServiceImpl.getConnectionInfo(WifiServiceImpl.java:2740)
        at android.net.wifi.IWifiManager$Stub.onTransact(IWifiManager.java:1047)
    callee: null 4649/12306

添加权限android.permission.ACCESS_WIFI_STATE。

3：继续执行。这次获取到了bssid，但是取得的值却是默认值：02:00:00:00:00:00。

这是什么问题？

我们看下获取wifiInfo的方法：

    /**
     * Return dynamic information about the current Wi-Fi connection, if any is active.
     * <p>
     * In the connected state, access to the SSID and BSSID requires
     * the same permissions as {@link #getScanResults}. If such access is not allowed,
     * {@link WifiInfo#getSSID} will return {@link #UNKNOWN_SSID} and
     * {@link WifiInfo#getBSSID} will return {@code "02:00:00:00:00:00"}.
     * {@link WifiInfo#getPasspointFqdn()} will return null.
     * {@link WifiInfo#getPasspointProviderFriendlyName()} will return null.
     *
     * @return the Wi-Fi information, contained in {@link WifiInfo}.
     */
    public WifiInfo getConnectionInfo() {
        try {
            return mService.getConnectionInfo(mContext.getOpPackageName(),
                    mContext.getAttributionTag());
        } catch (RemoteException e) {
            throw e.rethrowFromSystemServer();
        }
    }

可以看到注释中有这么一句话，获取bssid和ssid需要getScanResults相同的权限。

   /**
     * Return the results of the latest access point scan.
     * @return the list of access points found in the most recent scan. An app must hold
     * {@link android.Manifest.permission#ACCESS_FINE_LOCATION ACCESS_FINE_LOCATION} permission
     * in order to get valid results.
     */
    public List<ScanResult> getScanResults() {
        try {
            return mService.getScanResults(mContext.getOpPackageName(),
                    mContext.getAttributionTag());
        } catch (RemoteException e) {
            throw e.rethrowFromSystemServer();
        }
    }

好吧，需要ACCESS_FINE_LOCATION权限。

添加权限后，获得bssid.