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Ich schreibe eine App, die über WLAN eine Verbindung zu einem Telnet-Server herstellt. Ich habe einen Dienst, der die Socket-Verbindung verwaltet. Es funktioniert alles gut, aber wenn das Telefon schläft, trennt es das WiFi-Radio, was dazu führt, dass die Socket-Verbindung bricht (und eine SocketException auslöst).Wie wird über die Änderung des WLAN-Netzwerkstatus benachrichtigt?
Ich glaube, ich sollte in der Lage sein, einen Broadcast-Empfänger einzurichten, dessen onResume() -Methode aufgerufen wird, wenn die WLAN-Netzwerkverbindung verloren geht, und das würde mir erlauben, den Socket ordnungsgemäß herunterzufahren und wieder zu öffnen Das Netzwerk wird sofort wieder verbunden. Aber ich kann im Doc oder über die Suche nichts dergleichen finden.
Service-Code ist hier, wenn Sie es wollen, danke für die Hilfe, ich schätze es wirklich!
package com.wingedvictorydesign.LightfactoryRemote;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.OutputStream;
import java.net.InetSocketAddress;
import java.net.Socket;
import java.net.SocketException;
import java.net.SocketTimeoutException;
import android.app.Notification;
import android.app.NotificationManager;
import android.app.PendingIntent;
import android.app.Service;
import android.content.Intent;
import android.os.IBinder;
import android.os.RemoteCallbackList;
import android.os.RemoteException;
import android.text.Editable;
import android.util.Log;
import android.widget.Toast;
import android.os.Debug;
/**
* @author Max
*/
public class TelnetService extends Service {
private final int DISCONNECTED = 0;
private final int CONNECTED = 1;
// place notifications in the notification bar
NotificationManager mNM;
protected InputStream in;
protected OutputStream out;
protected Socket socket;
// the socket timeout, to prevent blocking if the server connection is lost.
protected final int SO_TIMEOUT = 250;
// holds the incoming stream from socket until it is ready to be read.
BufferedReader inputBuffer;
final RemoteCallbackList<TelnetServiceCallback> mCallbacks =
new RemoteCallbackList<TelnetServiceCallback>();
@Override
public void onCreate() {
super.onCreate();
Log.d("LightfactoryRemote", "TelnetService onCreate()");
mNM = (NotificationManager) getSystemService(NOTIFICATION_SERVICE);
}// end onCreate()
@Override
public void onDestroy() {
super.onDestroy();
Log.d("LightfactoryRemote", "TelnetService onDestroy()");
// Cancel the persistent notification, if it hasn't been already.
mNM.cancel(R.string.telnet_service_connected);
}// end onDestroy()
@Override
public IBinder onBind(Intent intent) {
Log.d("LightfactoryRemote", "TelnetService onBind()");
return mBinder;
}
@Override
public boolean onUnbind(Intent intent) {
super.onUnbind(intent);
Log.d("LightfactoryRemote", "TelnetService onUnBind()");
return true;
}
@Override
public void onStart(Intent intent, int startId) {
super.onStart(intent, startId);
Log.d("TelnetService", "TelnetService onStart()");
}
private final TelnetServiceInterface.Stub mBinder =
new TelnetServiceInterface.Stub() {
public void registerCallback(TelnetServiceCallback cb) {
if (cb != null) mCallbacks.register(cb);
}
public void unregisterCallback(TelnetServiceCallback cb) {
if (cb != null) mCallbacks.unregister(cb);
}
public String connectToTelnet(String Host, int Port)
throws RemoteException {
// android.os.Debug.waitForDebugger();
String hostInfo = null;
try {
socket = new java.net.Socket();
socket.setSoTimeout(SO_TIMEOUT);
socket.connect(new InetSocketAddress(Host, Port), 10000); //setup
// the port with a timeout of 10sec.
out = socket.getOutputStream();
/*
* in is wrapped in a reader, then in a Buffered reader. This is
* supposedly better for performance, and allows us to read a
* line at a time using the readLine() method.
*/
inputBuffer = new BufferedReader(new InputStreamReader(
socket.getInputStream()));
} catch (java.io.IOException e) {
Log.d("TelnetService.java", "Connection failed! " + e);
/*
* if the connection fails, return null for serverResponse,
* which will be handled appropriately on the client side.
*/
return hostInfo;
}
// now that the command has been sent, read the response.
hostInfo = readBuffer();
Log.d("TelnetService.java", hostInfo);
// notify the user that we are connected
showNotification(CONNECTED, Host, Port);
return hostInfo;
}// end connectToTelnet
/**
* Tests for a currently active connection. Three cases must be
* distinguished. 1. A connection attempt has not been made. Return
* false. 2. A connection attempt has been made, and socket is
* initialized, but no connection is active. isConnected() returns
* false. 3. A connection is active. isConnected() returns true.
*/
public boolean areYouThere() {
if (socket != null) {
boolean connectStatus = socket.isConnected();
return connectStatus;
} else {
return false;
}
}// end areYouThere
public void disconnect() {
try {
if (inputBuffer != null) {
inputBuffer.close();
}
if (socket != null) {
socket.close();
}
} catch (IOException e) {}
// Cancel the persistent notification.
mNM.cancel(R.string.telnet_service_connected);
}// end disconnect()
/**
* send the string to the telnet server, and return the response from
* server If the connection is lost, an IOException results, so return
* null to be handled appropriately on the client-side.
*
* @throws RemoteException
*/
public String sendToTelnet(String toTelnet) throws RemoteException {
if (out == null) {
/*
* if out is still null, no connection has been made. Throw
* RemoteException to be handled on the client side.
*/
throw new RemoteException();
} else {
byte arr[];
arr = (toTelnet + "\r" + "\n").getBytes();
try {
out.write(arr);
// now that the command has been sent, read the response.
String serverResponse = readBuffer();
return serverResponse;
} catch (IOException e) {
/*
* if a connection was made, but then lost, we end up here.
* throw a Remoteexception for handling by the client.
*/
Log.d("TelnetService", "IO exception" + e);
disconnect();
throw new RemoteException();
}
}// end else
}// end sendToTelnet
};// end ConnectService.Stub class
public String readBuffer() {
StringBuilder serverResponse = new StringBuilder();
int character;
try {
// keep reading new lines into line until there are none left.
while (inputBuffer.ready()) {
/*
* as each character is read, append it to serverResponse,
* throwing away the carriage returns (which read as glyphs),
* and the ">" prompt symbols.
*/
character = inputBuffer.read();
if ((character != 13) && (character != 62)) {
serverResponse.append((char) character);
}
}
}// end try
catch (SocketTimeoutException e) {
Log.d("TelnetService read()", "SocketTimeoutException");
} catch (IOException e) {
Log.d("TelnetService read()", "read() IO exception" + e);
}
return serverResponse.toString();
}
/**
* Show a notification while this service is running.
*/
private void showNotification(int event, String Host, int Port) {
// In this sample, we'll use the same text for the ticker and the
// expanded notification
CharSequence notificationText = "Connected to " + Host + " : " + Port;
// Set the icon, scrolling text and timestamp
Notification notification = new Notification(
R.drawable.notbar_connected, notificationText,
System.currentTimeMillis());
// set the notification not to clear when the user hits
// "Clear All Notifications"
notification.flags |= Notification.FLAG_NO_CLEAR;
// The PendingIntent to launch our activity if the user selects this
// notification
PendingIntent contentIntent = PendingIntent.getActivity(this, 0,
new Intent(this, LightfactoryRemote.class), 0);
// Set the info for the views that show in the notification panel.
notification.setLatestEventInfo(this,
getText(R.string.telnet_service_connected), notificationText,
contentIntent);
// Send the notification.
// We use a string id because it is a unique number. We use it later to
// cancel.
mNM.notify(R.string.telnet_service_connected, notification);
}// end showNotification()
} // end TelnetConnection
[Benachrichtigen, wenn Android-Gerät Netzwerkstatusänderungen] (http://www.singhajit.com/notify-android-device-network-status-changes/) –