【发布时间】：2015-02-20 11:30:01
【问题描述】：
我在这里阅读了大量关于使用 WakeLock 和 WifiLock 的教程和帖子，但仍然没有解决我的问题。
我正在编写一个应用程序，当您启动它时，它的唯一效果是创建和启动（前台）服务。该服务运行两个线程，即一个 UDP 广播侦听器（使用 java.io）和一个 TCP 服务器（使用 java.nio）。在服务的 onCreate 中，我获取了一个唤醒锁和一个 wifilock，并在 onDestroy 中释放它们。
只要手机处于唤醒状态，一切正常，但是当显示屏关闭时，UDP 广播接收器停止接收广播消息，并且在我再次打开显示屏之前不会收到任何消息。实际上，锁根本不起作用，放它们没有区别……我哪里错了？我确定我在某处做了一些愚蠢的事情，但我自己找不到。
这里有一些代码：
这是 Activity 的作用：
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
onlyStartService = true;
}@Override
protected void onStart() {
super.onStart();
Intent bIntent = new Intent(this, FatLinkService.class);
getApplicationContext().startService(bIntent);
getApplicationContext().bindService(bIntent, flConnection, BIND_AUTO_CREATE);
}
// service connection to bind idle service
private ServiceConnection flConnection = new ServiceConnection() {
public void onServiceConnected(ComponentName className, IBinder binder) {
linkService.MyLinkBinder flBinder = (LinkService.MylinkBinder) binder;
flServiceInstance = flBinder.getService();
if (onlyStartService) {
condLog("Service bound and finishing activity...");
finish();
}
}
public void onServiceDisconnected(ComponentName className) {
flServiceInstance = null;
}
};
@Override
protected void onStop() {
super.onStop();
if (fatFinish) {
Intent bIntent = new Intent(this, FatLinkService.class);
flServiceInstance.stopServices();
flServiceInstance.stopForeground(true);
flServiceInstance.stopService(bIntent);
condLog("Service stop and unbound");
flServiceInstance = null;
}
getApplicationContext().unbindService(flConnection);
}
服务是这样的：
public class LinkService extends Service {
InetAddress iaIpAddr, iaNetMask, iaBroadcast;
private final IBinder mBinder = new MyLinkBinder();
private linklistenBroadcast flBroadServer = null;
private linkTCPServer flTCPServer = null;
private linkUDPClient flBroadClient = null;
List<String> tokens = new ArrayList<String>();
private PowerManager.WakeLock wakeLock;
private WifiManager.WifiLock wifiLock;
public class MylLinkBinder extends Binder {
lLinkService getService() { return LinkService.this; }
}
@Override
public IBinder onBind(Intent intent) {
return mBinder;
}
@Override
public void onCreate() {
super.onCreate();
getLocks();
}
@Override
public int onStartCommand(Intent intent, int flags, int startId)
{
instantiateServices();
// notifies presence to other fat devices
condLog("Service notifying fat presence...");
flBroadClient = new LinkUDPClient();
flBroadClient.startSending(LinkProtocolConstants.BRCMD_PRESENCE + String.valueOf(LinkProtocolConstants.tcpPort), iaBroadcast, LinkProtocolConstants.brPort);
return START_STICKY;
}
public void getLocks() {
// acquire a WakeLock to keep the CPU running
condLog("Acquiring power lock");
WifiManager wm = (WifiManager) getApplicationContext().getSystemService(Context.WIFI_SERVICE);
wifiLock = wm.createWifiLock(WifiManager.WIFI_MODE_FULL , "MyWifiLock");
wifiLock.acquire();
PowerManager pm = (PowerManager) getApplicationContext().getSystemService(Context.POWER_SERVICE);
wakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, "MyWakeLock");
wakeLock.acquire();
}
public void stopServices() {
if (flTCPServer != null)
flTCPServer.stopServer();
if (flBroadServer != null)
flBroadServer.stopSelf();
}
private void instantiateServices() {
populateAddresses(); // just obtain iaIpAddr
if (flTCPServer == null) {
condLog("Instantiating TCP server");
flTCPServer = new LinkTCPServer(iaIpAddr, FatLinkProtocolConstants.tcpPort);
flTCPServer.execute();
}
if (flBroadServer == null) {
condLog("Instantiating UDP broadcast server");
Intent notifyIntent = new Intent(this, LinkMain.class); // this is the main Activity class
notifyIntent.setFlags(Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP);
notifyIntent.setAction("FROM_NOTIFICATION");
PendingIntent notifyPIntent = PendingIntent.getActivity(this, 0, notifyIntent, 0);
Notification fixNotification = new Notification.Builder(getApplicationContext())
.setContentTitle("Link")
.setSmallIcon(R.mipmap.imgLink)
.setContentIntent(notifyPIntent)
.build();
startForeground(1234, fixNotification);
flBroadServer = new LinklistenBroadcast();
flBroadServer.start();
}
}
private final class LinklistenBroadcast extends Thread {
private boolean bStopSelf = false;
DatagramSocket socket;
public void stopSelf() {
bStopSelf = true;
socket.close();
}
@Override
public void run() {
condLog( "Listening broadcast thread started");
bStopSelf = false;
try {
//Keep a socket open to listen to all the UDP trafic that is destinated for this port
socket = new DatagramSocket(null);
socket.setReuseAddress(true);
socket.setSoTimeout(LinkGeneric.BR_SOTIMEOUT_MILS);
socket.setBroadcast(true);
socket.bind(new InetSocketAddress(InetAddress.getByName("0.0.0.0"), FatLinkProtocolConstants.brPort));
while (true) {
condLog("Ready to receive broadcast packets...");
//Receive a packet
byte[] recvBuf = new byte[1500];
DatagramPacket packet = new DatagramPacket(recvBuf, recvBuf.length);
try {
socket.receive(packet);
} catch (InterruptedIOException sException) {
condLog(sockExcept.toString());
break;
} catch (SocketException sockExcept) {
condLog(sockExcept.toString());
}
if (bStopSelf) {
condLog("Broadcast server stopped...");
break;
}
int len = packet.getLength();
String datarecvd = new String(packet.getData()).trim();
//datarecvd = datarecvd.substring(0, len);
//Packet received
String message = new String(packet.getData()).trim();
condLog("<<< broadcast packet received from: " + packet.getAddress().getHostAddress() + " on port: " + packet.getPort() + ", message: " + message);
if (packet.getAddress().equals(iaIpAddr)) {
condLog("Ooops, it's me! discarding packet...");
continue;
}
else
condLog("<<< Packet received; data size: " + len + " bytes, data: " + datarecvd);
//See if the packet holds the right command (message)
// protocol decode
// here do some tuff
} catch (IOException ex) {
condLog(ex.toString());
}
if (socket.isBound()) {
condLog( "Closing socket");
socket.close();
}
condLog( "UDP server thread end.");
flTCPServer = null;
flBroadServer = null;
}
public boolean isThreadRunning() {
return !bStopSelf;
};
}
// Utility functions
public boolean checkBroadcastConnection (DatagramSocket socket, int timeOutcycles) {
int tries = 0;
while (!socket.isConnected()) {
tries++;
if (tries >= timeOutcycles)
return false;
}
return true;
}
@Override
public void onDestroy() {
super.onDestroy();
if (wakeLock != null) {
if (wakeLock.isHeld()) {
wakeLock.release();
}
}
if (wifiLock != null) {
if (wifiLock.isHeld()) {
wifiLock.release();
}
}
}
}
最后，这是清单：
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
package="xxxxxx.ink" >
<uses-permission android:name="android.permission.ACCESS_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_WIFI_STATE" />
<uses-permission android:name="android.permission.CHANGE_NETWORK_STATE" />
<uses-permission android:name="android.permission.INTERNET" />
<uses-permission android:name="android.permission.ACCESS_NETWORK_STATE" />
<uses-permission android:name="android.permission.WAKE_LOCK" />
<uses-permission android:name="android.permission.WRITE_SETTINGS" />
<application
android:allowBackup="true"
android:icon="@mipmap/imgLinkmascotte"
android:label="@string/app_name"
android:theme="@style/AppTheme" >
<activity
android:name=".LinkMain"
android:label="@string/app_name"
android:theme="@android:style/Theme.Translucent.NoTitleBar.Fullscreen">
<intent-filter>
<action android:name="android.intent.action.MAIN" />
<category android:name="android.intent.category.LAUNCHER" />
</intent-filter>
</activity>
<service android:name=".LinkService" />
</application>
</manifest>
我已阅读 this，我怀疑问题是否相同，但它实际上发生在我尝试过的所有手机上（galaxy Tab 7.1、galaxy tag 10、Galaxy SIII、Galaxy Note 3 Neo, Galaxy SIII mini) 安卓版本从 4.0 到 4.4。
我已经尝试过here 发布的解决方案，但一切都发生了变化（再次……有点令人沮丧）。
我什至尝试在我尝试过的所有手机中将“保持 wifi 选项处于待机状态”设置为“始终”，但仍然没有。
我研究了 WakeFulIntentService 类，它应该像每个人所说的那样工作，但我看不出我的代码有任何显着不同。
我真的希望有人能帮助我，从上周开始我就一直坚持这个。
编辑：按照 waqaslam 的回答，我检查了在 Wifi-Advaced 设置中具有“Wifi 优化”选项的设备，一旦我取消该选项，它实际上就可以工作。所以，现在，问题变成了：我可以在高级菜单中没有显示该选项的设备中禁用 Wifi 优化吗？正如我在下面的评论中所写，这似乎与 android 版本无关，因为我有两台设备（均为三星）4.4.2 并且它们没有显示该选项。
新编辑：从编辑的 waqaslam 答案中，我尝试将多播锁添加到我的服务中，但再次发生任何变化。这越来越烦人了，android 几乎没有什么简单明了的东西。
非常感谢 C.
【问题讨论】：
-
你的安卓版本和设备是什么？
-
感谢您的评论。我把它们写在了文章的最后。更准确地说，我已经尝试过 4.0.x（现在不记得了）、4.1.2 和 4.4.2。
-
我也遇到了同样烦人的问题。你找到解决办法了吗？
-
没办法。广播对我来说根本不可能。
标签： java android android-wifi wakelock