Android 默认AP名字，以及AP名字存储路径

最近在修改Settings.apk，其中有一条需求是修改默认的ap名字。于是我们跟踪一下源码来解决一下困扰我的问题。

首先在Settings\src\com\android\settings\TetherSettings.java的代码中

private void initWifiTethering() {
final Activity activity = getActivity();
mWifiManager = (WifiManager) getSystemService(Context.WIFI_SERVICE);
mWifiConfig = mWifiManager.getWifiApConfiguration();
mSecurityType = getResources().getStringArray(R.array.wifi_ap_security);

mCreateNetwork = findPreference(WIFI_AP_SSID_AND_SECURITY);

if (mWifiConfig == null) {
final String s = activity.getString(
com.android.internal.R.string.wifi_tether_configure_ssid_default);
mCreateNetwork.setSummary(String.format(activity.getString(CONFIG_SUBTEXT),
s, mSecurityType[WifiApDialog.OPEN_INDEX]));
} else {
int index = WifiApDialog.getSecurityTypeIndex(mWifiConfig);
mCreateNetwork.setSummary(String.format(activity.getString(CONFIG_SUBTEXT),
mWifiConfig.SSID,
mSecurityType[index]));
}
}

WifiManager的getWifiApConfiguration可以获取ap相关信息。进入getWifiApConfiguration查看可以得知该类是调用WifiService，WifiService是调用WifiServiceImpl的getWifiApConfiguration。

/**
* see {@link WifiManager#getWifiApConfiguration()}
* @return soft access point configuration
*/
public WifiConfiguration getWifiApConfiguration() {
enforceAccessPermission();
return mWifiStateMachine.syncGetWifiApConfiguration();
}

在WifiStateMachine.java中

public WifiConfiguration syncGetWifiApConfiguration() {
Message resultMsg = mWifiApConfigChannel.sendMessageSynchronously(CMD_REQUEST_AP_CONFIG);
WifiConfiguration ret = (WifiConfiguration) resultMsg.obj;
resultMsg.recycle();
return ret;
}

其中针对mWifiApConfigChannel的定义如下：

class InitialState extends State {
@Override
public void enter() {
mWifiNative.unloadDriver();
if (mWifiP2pChannel == null) {
mWifiP2pChannel = new AsyncChannel();
mWifiP2pChannel.connect(mContext, getHandler(),
mWifiP2pServiceImpl.getP2pStateMachineMessenger());
}
if (mWifiApConfigChannel == null) {
mWifiApConfigChannel = new AsyncChannel();
WifiApConfigStore wifiApConfigStore = WifiApConfigStore.makeWifiApConfigStore(
mContext, getHandler());
wifiApConfigStore.loadApConfiguration();
mWifiApConfigChannel.connectSync(mContext, getHandler(),
wifiApConfigStore.getMessenger());
}
}

其中WifiApConfigStore wifiApConfigStore = WifiApConfigStore.makeWifiApConfigStore(

mContext, getHandler());就是我们最后所有问题的答案。在WifiApConfigStore.java这个类中：

class WifiApConfigStore extends StateMachine {
private Context mContext;
private static final String TAG = "WifiApConfigStore";
private static final String AP_CONFIG_FILE = Environment.getDataDirectory() +
"/misc/wifi/softap.conf";

这个文件就是存放修改ap名字的文件。而：

/* Generate a default WPA2 based configuration with a random password.
We are changing the Wifi Ap configuration storage from secure settings to a
flat file accessible only by the system. A WPA2 based default configuration
will keep the device secure after the update */
private void setDefaultApConfiguration() {
WifiConfiguration config = new WifiConfiguration();
config.SSID = mContext.getString(R.string.wifi_tether_configure_ssid_default);
config.allowedKeyManagement.set(KeyMgmt.WPA2_PSK);
String randomUUID = UUID.randomUUID().toString();
//first 12 chars from xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx
config.preSharedKey = randomUUID.substring(0, 8) + randomUUID.substring(9,13);
sendMessage(WifiStateMachine.CMD_SET_AP_CONFIG, config);
}

也就是获取默认ap名字和密码的代码。