Databases
StackOverflow2013
Postsdbo
POHow to be notified on wifi network status change?
 

Note that there are some explanatory texts on larger screens.

plurals
  1. POHow to be notified on wifi network status change?
    primarykey
    data
    text
    <p>I am writing an app that connects to a telnet server via wifi. I have a service that manages the socket connection. It all works fine, but when the phone sleeps it disconnects the wifi radio, which causes the socket connection to break (and throws a SocketException).</p> <p>I feel like I should be able to set up a a broadcast receiver whose onResume() method is called when the wifi network connection is lost, and that would allow me to gracefully shut down the socket, and re-open it if the network is immediately re-connected. But I can't find anything like that in the doc or via searching.</p> <p>Service code is here if you want it, thanks for the help, I really appreciate it!</p> <pre><code>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&lt;TelnetServiceCallback&gt; mCallbacks = new RemoteCallbackList&lt;TelnetServiceCallback&gt;(); @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 "&gt;" prompt symbols. */ character = inputBuffer.read(); if ((character != 13) &amp;&amp; (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 </code></pre>
    singulars
    1. This table or related slice is empty.
    1. This table or related slice is empty.
    1. PTQuestion
    1. USMr_and_Mrs_D
    1. UScatdotgif
    plurals
    1. This table or related slice is empty.
    1. PL
      singulars
      1. LTLinked
    2. PL
      singulars
      1. LTLinked
    1. This table or related slice is empty.
    1. PO
      singulars
      1. PTAnswer
    2. PO
      singulars
      1. PTAnswer
    3. PO
      singulars
      1. PTAnswer
    1. VO
      singulars
      1. POHow to be notified on wifi network status change?
      1. This table or related slice is empty.
      1. VTUpMod
    2. VO
      singulars
      1. POHow to be notified on wifi network status change?
      1. USMitul Nakum
      1. VTFavorite
    3. VO
      singulars
      1. POHow to be notified on wifi network status change?
      1. USLance Lefebure
      1. VTFavorite
    1. This table or related slice is empty.
 

Querying!

 
Guidance
A row detail

Detail views are divided into sections. All the information in the data section comes from columns in the selected row. The other sections display data from other, related rows.

Related data can be related in a to-one or a to-many fashion. Captions of data related in a to-many fashion link to a list view showing a filtered view of the table.

Try moving around until you find a non-empty to-many entry and click on the label to get to one. You can move back to the root by clicking on the database name in the header.

SQuiL has stopped working due to an internal error.

If you are curious you may find further information in the browser console, which is accessible through the devtools (F12).

Reload