I have an Activity which calls an Async task to accept socket connections through a predefined InetAddress.
The Async task calls another Async task to listen for messages in. but it hangs on the get input stream
I have been racking my brain for hours and cannot work out why it is hanging...any help please.
public void startSocketListener(InetAddress groupOwnerAddress) {
// TODO Auto-generated method stub
AcceptClientThread accept;
try {
accept = new AcceptClientThread();
accept.execute();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public class AcceptClientThread extends AsyncTask<Void, String, String>{
public AcceptClientThread() throws IOException{
}
#Override
protected void onCancelled() {
// TODO Auto-generated method stub
try {
serverSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
Log.e("CONNECTION ERR", "Could not close serverSocket " + e.toString());
}
super.onCancelled();
}
#Override
protected String doInBackground(Void... params) {
try {
serverSocket = new ServerSocket(port);
} catch (IOException e) {
Log.e("CONNECTION ERR","Could not listen on port: " + port);
onCancelled();
}
while (listening){
try {
Log.i("CONNECTION", "AWAITING CONNECTION TO CLIENT");
Socket newSocket = serverSocket.accept();
Log.i("CONNECTION", "CONNECTED TO CLIENT");
ListenerThread lThread = new ListenerThread(newSocket);
lThread.execute("Do it");
Log.i("CONNECTION", "ACCEPTED CLIENT");
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
onProgressUpdate("could not accept client");
}
}
Log.i("CONNECTION", "close socket");
try {
serverSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return "table connected";
}
#Override
protected void onProgressUpdate(String... values) {
super.onProgressUpdate(values);
// received data is first element in the String
//Toast.makeText(KitchenActivity.this, values[0], Toast.LENGTH_SHORT).show();
}
}
public class ListenerThread extends AsyncTask<String, Order, Void> {
private Socket socket;
ObjectInputStream ois;
public ListenerThread(Socket socket){
this.socket = socket;
try {
ois = new ObjectInputStream(this.socket.getInputStream()); //hangs here
} catch (StreamCorruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
According to The Docs
Threading rules
There are a few threading rules that must be followed
for this class to work properly:
The AsyncTask class must be loaded on the UI thread. This is done
automatically as of JELLY_BEAN. The task instance must be created on
the UI thread.
You can handle this by calling your new Thread in the onPostExecute() of your first AsyncTask after your accept() is successful, as onPostExecute() runs on the UI
Also, without looking at it more, I believe that you would want to break out of your while loop in the first task after it accepts the request. Then when you need to make another connection you create a new instance of this task in your UI and execute it again. I'm not positive about that last part without looking at it longer but that seems right
I'm not sure, but I guess you only can call AsyncTask.execute() from UI-thread, and you are trying to do it from doInBackground(), which runs in separate thread.
Related
I need to limit the number of client that can connect to the server . I only want 3 clients that can connect not more.
I tried if else conditions. and some loops.
public class server {
ServerSocket ss;
boolean quite=false;
ArrayList<MultiServerConnection> OurDomainsConnections=new ArrayList<MultiServerConnection>();
public static void main(String[] args) {
new server();
}
public server() {
try {
//TODO use method to take this as an input from user)
ss=new ServerSocket(3333);//here we are using connection 3333 (change as you want
while(!quite)
{
Socket s=ss.accept();//when a connection to the domain is found we accept it
MultiServerConnection OurConnection = new MultiServerConnection(s,this);
OurConnection.start();//Start Thread
OurDomainsConnections.add(OurConnection);//add connection to our Domain Connection
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//make sure its bloody same with client it took my 15 min to realize that XD
}
}
public class MultiServerConnection extends Thread {
Socket s;
DataInputStream din;
DataOutputStream dout;
server ss;
boolean quite=false;
public MultiServerConnection(Socket OurSocket,server OurServer)
{
super("MultiServerConnection");//server connection thread
this.s=OurSocket;
this.ss=OurServer;
}
public void ServerOutClientIn(String OutText)
{
try {
long ThreadID=this.getId();
dout.writeUTF(OutText);
dout.flush();//this is because of a buffer error :<
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void ServerOutAllClientIn(String OutText)
{
for(int i=0;i<ss.OurDomainsConnections.size();i++)
{
MultiServerConnection Connection=ss.OurDomainsConnections.get(i);
Connection.ServerOutClientIn(OutText);
}
}
public void run()
{
try {
din=new DataInputStream(s.getInputStream());
dout=new DataOutputStream(s.getOutputStream());
while(!quite)
{
while(din.available()==0)
{
try {
Thread.sleep(1);//sleep if there is not data coming
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String ComingText=din.readUTF();
ServerOutAllClientIn(ComingText);
}
din.close();
dout.close();
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
public class MultiClients extends Thread {
Socket s;
DataInputStream din;
DataOutputStream dout;
boolean quite=false;
public ClientData c;
public interface1 GUI;
public MultiClients(Socket OurMultiSocket, interface1 gui)
{
s=OurMultiSocket;
c=new ClientData();
GUI=gui;
}
public void ClientOutServerIn(String Text)
{
//write the line from console to server
try {
if(Text.equals("change channel"))
{
System.out.print("sending changing channel: "+Text+"\n");
dout.writeUTF(Text);
dout.flush();
}
else if(Text.equals("new user"))
{
System.out.print("sending new user: "+ Text+"\n");
dout.writeUTF(Text+":"+c.GetName()+"="+c.GetChannel());
dout.flush();
}
else
{
dout.writeUTF(c.GetChannel()+"="+this.getName()+": "+Text);
dout.flush();
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void SetClient(String channel,String Name)
{
c.SetName(Name);
c.SetChannel(channel);
}
public void run()
{
try {
din=new DataInputStream(s.getInputStream());
dout=new DataOutputStream(s.getOutputStream());
while(!quite)
{
try {
while(din.available()==0)
{
try {
Thread.sleep(1);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
//if there is something just show it on console
//and then go back and do the same
String reply=din.readUTF();
String Chan=ExtractChannel(reply);
String name=ExtractName(reply);
/*if (reply.equals("change channel"))
{
System.out.print("changing channel in body: "+reply+"\n");
//GUI.ClearDisplay();
setChangedChannel();
}*/
if(name.equals("new user"))
{
System.out.print("new user in body: "+reply+"\n");
//GUI.ClearDisplay();
setChannel(reply);
}
else
{
PrintReply(Chan,reply);
}
//System.out.println(reply);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
try {
din.close();
dout.close();
s.close();
} catch (IOException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
try {
din.close();
dout.close();
s.close();
} catch (IOException x) {
// TODO Auto-generated catch block
x.printStackTrace();
}
}
}
public void CloseClient()
{
try {
din.close();
dout.close();
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public String ExtractName(String x)
{
String[]Y=x.split(":");
return Y[0];
}
public String ExtractChannel(String X)
{
String[]Y=X.split("=");
return Y[0];
}
public void PrintReply(String Chan,String Rep)
{
if(c.GetChannel().equals(Chan))
{
String []Y=Rep.split("=");
GUI.setDisplay(Y[1]);
//System.out.println(Y[1]+"\n \n \n \n");
}
}
public void setChannel(String x)
{
String []Y=x.split(":");
String []Z=Y[1].split("=");
System.out.print("setting "+Z[0]+" channel to "+Z[1]+"\n");
GUI.setUserInChannel(Z[0]);
}
public void setChangedChannel()
{
GUI.setUserInChannel(c.GetName()+": "+c.GetChannel());
}
class ClientData
{
public String ClientName;
public String channel;
public void SetChannel(String Chan)
{
channel=Chan;
}
public void SetName(String name)
{
ClientName=name;
}
public String GetChannel()
{
return channel;
}
public String GetName()
{
return ClientName;
}
}
}
in this code. more than 5 user can can chat together. i only want to allow 3 user to connect and to chat.
You can use AtomicInteger as a counter to check how many clients you have already connected:
import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.util.ArrayList;
import java.util.concurrent.atomic.AtomicInteger;
public class server {
ServerSocket ss;
boolean quite=false;
ArrayList<MultiServerConnection> OurDomainsConnections=new ArrayList<MultiServerConnection>();
final AtomicInteger runningCount = new AtomicInteger(0);
final Integer limit = 3;
public static void main(String[] args) {
new server();
}
public server() {
try {
//TODO use method to take this as an input from user)
ss=new ServerSocket(3333);//here we are using connection 3333 (change as you want
while(!quite)
{
Socket s=ss.accept();//when a connection to the domain is found we accept it
if (runningCount.incrementAndGet() < limit){ //increment number of clients and check
MultiServerConnection OurConnection = new MultiServerConnection(s,this, runningCount::decrementAndGet);
OurConnection.start();//Start Thread
OurDomainsConnections.add(OurConnection);//add connection to our Domain Connection
} else {
runningCount.decrementAndGet();
s.close();
System.out.println("limit exceeded");
}
}
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}//make sure its bloody same with client it took my 15 min to realize that XD
}
}
interface Callback {
void call();
}
class MultiServerConnection extends Thread {
Socket s;
DataInputStream din;
DataOutputStream dout;
server ss;
boolean quite=false;
final Callback callbackOnFinish;
public MultiServerConnection(Socket OurSocket,server OurServer, Callback callbackOnFinish)
{
super("MultiServerConnection");//server connection thread
this.s=OurSocket;
this.ss=OurServer;
this.callbackOnFinish = callbackOnFinish;
}
public void ServerOutClientIn(String OutText)
{
try {
long ThreadID=this.getId();
dout.writeUTF(OutText);
dout.flush();//this is because of a buffer error :<
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void ServerOutAllClientIn(String OutText)
{
for(int i=0;i<ss.OurDomainsConnections.size();i++)
{
MultiServerConnection Connection=ss.OurDomainsConnections.get(i);
Connection.ServerOutClientIn(OutText);
}
}
public void run()
{
try {
din=new DataInputStream(s.getInputStream());
dout=new DataOutputStream(s.getOutputStream());
while(!quite)
{
while(din.available()==0)
{
try {
Thread.sleep(1);//sleep if there is not data coming
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
String ComingText=din.readUTF();
ServerOutAllClientIn(ComingText);
}
din.close();
dout.close();
s.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} finally {
callbackOnFinish.call();
}
}
}
When a new connection is accepted runningCount is atomically increased and value is got by runningCount.incrementAndGet(). Then if value below the limit - new MultiServerConnection is created with a callback. The callback is used for decrementing a counter on exit. If counter equal or above the limit => socket will be closed and error message printed. It is good to have a message passed to the socket.
P.S. I have not reviewed your solution. I've just added the feture you requested.
Hello dear programmers ,
I am trying to make a tic tac toe game using android, my android application contains several activities, one of these activities can the allows client to send a message to the server asking if X user wants to challenge, if the user accepts the challenge the server messages me and we both move forward to another activity.
My server is running as a regular java code on my PC, this is my server code :
public class Server {
ServerSocket serverSocket;
ArrayList<ServerThread> allClients = new ArrayList<ServerThread>();
public static void main(String[] args) {
new Server();
}
public Server() {
// ServerSocket is only opened once !!!
try {
serverSocket = new ServerSocket(6000);
System.out.println("Waiting on port 6000...");
boolean connected = true;
// this method will block until a client will call me
while (connected) {
Socket singleClient = serverSocket.accept();
// add to the list
ServerThread myThread = new ServerThread(singleClient);
allClients.add(myThread);
myThread.start();
}
// here we also close the main server socket
serverSocket.close();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
class ServerThread extends Thread {
Socket threadSocket;
String userName;
boolean isClientConnected;
InputStream input;
ObjectInputStream ois;
OutputStream output;
ObjectOutputStream oos; // ObjectOutputStream
public ServerThread(Socket s) {
threadSocket = s;
}
public void sendText(String text) {
try {
oos.writeObject(text);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
try {
input = threadSocket.getInputStream();
ois = new ObjectInputStream(input);
output = threadSocket.getOutputStream();
oos = new ObjectOutputStream(output);
userName = (String) ois.readObject();
isClientConnected = true;
System.out.println("User " + userName + " has connected");
while (isClientConnected) {
String singleText = (String) ois.readObject();
System.out.println(singleText);
for (ServerThread t : allClients)
t.sendText(singleText);
// oos.writeObject(singleText);
}
// close all resources (streams and sockets)
ois.close();
oos.close();
threadSocket.close();
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
I use the communication between clients in only two activies, both activites contain the same connectUser() code :
public class MenuActivity extends Activity {
public static final String HOST = "10.0.2.2";
public static final int PORT = 6000;
static ConnectThread clientThread;
boolean isConnected;
static boolean isOnline = false;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_menu);
runOnUiThread(new Runnable() {
public void run() {
connectUser();
}
});
}
#Override
public boolean onCreateOptionsMenu(Menu menu) {
// Inflate the menu; this adds items to the action bar if it is present.
getMenuInflater().inflate(R.menu.main, menu);
return true;
}
public void connectUser() {
clientThread = new ConnectThread();
clientThread.start();
}
class ConnectThread extends Thread {
InputStream input;
OutputStream output;
ObjectOutputStream oos;
Socket s;
public void sendText(String text) {
try {
oos.writeObject(text);
System.out.println(text);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
try {
s = new Socket(HOST, PORT);
output = s.getOutputStream();
oos = new ObjectOutputStream(output);
oos.writeObject(un);
isOnline = true;
isConnected = true;
new ListenThread(s).start();
} catch (UnknownHostException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
class ListenThread extends Thread {
Socket s;
InputStream input;
ObjectInputStream ois;
public ListenThread(Socket s) {
this.s = s;
try {
input = s.getInputStream();
ois = new ObjectInputStream(input);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public void run() {
while (isConnected) {
try {
final String inputMessage = (String) ois.readObject();
//do something with the message }
} catch (Exception e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
}
}
}
I use this code this code to send message to the server :
clientThread.sendText(user + " " + opponent + " play");
The problem is that when I create the connection at the first activity, then move to the second activity I create another connection , which means so far I am having two connections, same with other clients and then the server seems to return a timed out error.
My question is how to do a global client variable that is created once and can be used in each activity. I saw many suggestions like socket service or asyntask , but I need more direction and help
Thanks in advance.
Add a sub class of Application to your project and update application tag and add this class as android:name:
<application
android:name="com.your.app.MyApplication"
...
and then create a static reference to your Socket connection in MyApplication class:
private static Socket connection;
and then add a static method to access this object:
public static Socket getConnection() {
if( connection == null) {
// initialize connection object here
}
return connection;
}
Now you have a global object!
I have implemented a Steaming API for twitter. I get the streams perfectly. However, My program never ends. I have tried many combinations but can't figure out why. I am suing Apache AsyncHttpClient in java. My goal is to start the stream for example for 10 seconds, get the streams, and gracefully close the stream and exit the application (I am expecting this to happen when my Main method ends naturally). This is the code below:
public static void main(String[] args) throws Exception
{
TwitterStreamingHttpClient client = new TwitterStreamingHttpClient();
Executor ex = Executors.newSingleThreadExecutor();
ex.execute(client);
Thread.sleep(5000);
client.ceaseStream();
LOG.debug("Keeps running");
}
and this:
public class TwitterStreamingHttpClient extends DefaultHttpAsyncClient implements Runnable
{
private final static Logger LOG = LoggerFactory.getLogger(TwitterStreamingHttpClient.class);
/**
* #throws IOReactorException
*/
public TwitterStreamingHttpClient() throws IOReactorException
{
super();
// TODO: parametrize it, load from config file, spring config file?
this.getCredentialsProvider().setCredentials(new AuthScope("stream.twitter.com", 80),
new UsernamePasswordCredentials("username", "password"));
this.start();
}
public void initiateStream() throws UnsupportedEncodingException, InterruptedException, ExecutionException
{
String requestContent = new String();
requestContent = "track=NothingFeelsBetterThan";
Future future = this.execute(HttpAsyncMethods.createPost(
"https://stream.twitter.com/1.1/statuses/filter.json", requestContent,
ContentType.APPLICATION_FORM_URLENCODED), new TwitConsumer(), null);
Boolean result = future.get();
if(result==null)
{
LOG.error("Requested to close stream!");
return;
}
}
public void ceaseStream()
{
try
{
this.shutdown();
LOG.info("Shutting down the stream");
}
catch (InterruptedException e)
{
LOG.debug("InterruptedException {}", e);
}
}
/*
* (non-Javadoc)
*
* #see java.lang.Runnable#run()
*/
public void run()
{
Thread.currentThread().setName("initiateSTream Thread");
try
{
initiateStream();
Thread.currentThread().interrupt();
}
catch (UnsupportedEncodingException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (InterruptedException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
catch (ExecutionException e)
{
// TODO Auto-generated catch block
e.printStackTrace();
}
}
I tried to add a return whereever I though it mightbe helpful. but no luck. Can someone help me with this?
Edit 1: When I use the debug mode, I can see that the "initiateSTream Thread" thread. is still running while the main thread is gone!
Edit 2 (Solution): In the main method, I replaced:
Executor ex = Executors.newSingleThreadExecutor();
ex.execute(client);
with:
Thread thread = new Thread(client);
thread.start();
Now my programs ends after the designated time of streaming. But why? What is the difference between the two approaches?!
My Android App needs some basic data to run. This data is downloaded from a server using JSON. In Xcode I simply used the sendsynchronous request but I noticed that Eclipse gives me a error when i do networking on the main ui.
Found a lot of stuff on asynctask but i want my app to wait till the required data is downloaded (synchronous?).
I tried using asynctask .execute().get() and setting the variables in onPostExecute but when I return the variable I get a NullPointerException. Does someone know how to make this work? I really need this data before the app can run so I want my app to wait till the data is downloaded.
MainActivity calls this:
SingletonClass appIDSingleton = SingletonClass.getInstance();
this.ID = appIDSingleton.getAppID();
Singleton Class:
public String getAppID() {
try {
new DownloadAppID().execute(APP_ID_URL).get(5000, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return AppID; //AppID is still NULL (because the download isnt finished yet?)
}
private class DownloadAppID extends AsyncTask<String, Void, String> {
#Override
protected String doInBackground(String... urls) {
String response = "";
for (String url : urls) {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet httpGet = new HttpGet(url);
try {
HttpResponse execute = client.execute(httpGet);
InputStream content = execute.getEntity().getContent();
BufferedReader buffer = new BufferedReader(new InputStreamReader(content));
String s = "";
while ((s = buffer.readLine()) != null) {
response += s;
}
} catch (Exception e) {
e.printStackTrace();
}
}
return response;
}
#Override
protected void onPostExecute(String result) {
System.out.println(result);
AppID = result;
}
}
You need to understand that your getAppID method can't return a result that is going to be computed asynchronously.
You could for instance provide a listener to your async task in order to notify when app ID is available:
SingletonClass appIDSingleton = SingletonClass.getInstance();
appIDSingleton.getAppID(new AppIdDownloadListener() {
#Override
public void appIDAvailable(String appId) {
this.ID = appId;
}
});
public void getAppID(AppIdDownloadListener listener) {
try {
new DownloadAppID(listener).execute(APP_ID_URL).get(5000, TimeUnit.MILLISECONDS);
} catch (InterruptedException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (ExecutionException e) {
// TODO Auto-generated catch block
e.printStackTrace();
} catch (TimeoutException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
}
public interface AppIdDownloadListener {
public void appIDAvailable(String appId);
}
private class DownloadAppID extends AsyncTask<String, Void, String> {
private AppIdDownloadListener listener;
public DownloadAppID(AppIdDownloadListener listener) {
this.listener = listener;
}
#Override
protected String doInBackground(String... params) {
/* Your stuff here */
}
#Override
protected void onPostExecute(String result) {
System.out.println(result);
listener.appIDAvailable(result);
}
}
I am trying to get the Message-Id of the sent message by using listeners.
I am implementing
javax.mail.event.TransportListener with concrete methods given in code sample.
It listens to javax.mail.event.TransportEvent which gets generated when void javax.mail.Transport.sendMessage(.....) is called.
To my surprise I get none of the method gets called when I actually send the mail..??? When does it actually get called ? Do I need to add any wait time after calling sendMessage(..)??
Doesn't it happen in real time ?
#Override
public void messageDelivered(TransportEvent e)
{
try {
System.out.println(e.getMessage().getHeader("Message-Id")[0]);
} catch (MessagingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
#Override
public void messageNotDelivered(TransportEvent e)
{
try {
System.out.println(e.getMessage().getHeader("Message-Id")[0]);
} catch (MessagingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
#Override
public void messagePartiallyDelivered(TransportEvent e)
{
try {
System.out.println(e.getMessage().getHeader("Message-Id")[0]);
} catch (MessagingException e1) {
// TODO Auto-generated catch block
e1.printStackTrace();
}
}
Did you register your listener with the Transport instance that's being used to send the message? Remember that the static Transport.send() method creates its own Transport instance that you never see.