我正在编写一个通过wifi连接到telnet服务器的应用程序.我有一个管理套接字连接的服务.一切正常,但是当手机休眠时,它会断开wifi无线电,导致套接字连接中断(并抛出SocketException).

我觉得我应该能够设置一个广播接收器,当wifi网络连接丢失时调用onResume()方法,这将允许我优雅地关闭套接字,并在网络立即重新打开它重新连接.但我在文档或搜索中找不到类似的东西.

服务代码在这里,如果你需要它,感谢您的帮助,我真的很感激！

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 mCallbacks =

new RemoteCallbackList();

@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 + "" + "

").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