I'm using the atmosphere framework in my application.
https://github.com/Atmosphere/atmosphere
I've extended the AbstractReflectorAtmosphereHandler class and implemented the
-onRequest
-destroy
-onstatechanged
methods.
When a client wants to send a message to the server:
subSocket.push(jQuery.stringifyJSON({ data: "blahblah", source:"client" }));
The onRequest function is called; however the message
Object message = atmosphereResource.getAtmosphereResourceEvent().getMessage();
Is empty.
Than I tried using the onstatechanged which is called every time
(1) The remote connection gets closed, either by a browser or a proxy
(2) The remote connection reach its maximum idle time (AtmosphereResource.suspend))
(3) Everytime a broadcast operation is executed (broadcaster.broadcast)
However even after filtering out 1 and 2
public void onStateChange(AtmosphereResourceEvent event)
throws IOException {
if (source.equals("client") && !event.isResumedOnTimeout() && !event.isResuming()){
System.out.println("message form client");
System.out.println(message.toString());
} else {
//normal onstatechanged code from AbstractReflectorAtmosphereHandler
}
However the message is printed randomly between 2 and 4 times. It should only be called once.
So my question is: Can I acces the message inside the onRequest method or why is the onStateChange called so many times.
edit: from the answer given by jF I've been able to acces the message inside the onRequest function. (I'm not sure however if that is what he actually meant).
public void onRequest(AtmosphereResource resource) throws IOException {
//Object message = resource.getAtmosphereResourceEvent().getMessage(); //is empty why?
//leave connection open
resource.suspend();
BufferedReader reader = resource.getRequest().getReader();
Object message = reader.readLine();
if (message !=null){
System.out.println("**onRequest: "+message.toString());
}
}
You need to read the request's body by doing, in your onStateChange:
atmosphereResource.getRequest().getReader (or getInputStream).
Maybe this helpes other people:
public void onRequest(AtmosphereResource resource) throws IOException {
//Object message = resource.getAtmosphereResourceEvent().getMessage(); //is empty why?
//leave connection open
resource.suspend();
BufferedReader reader = resource.getRequest().getReader();
Object message = reader.readLine();
if (message !=null){
Object obj = JSONValue.parse(message.toString());
JSONObject jsonObject = (JSONObject) obj;
Object source = jsonObject.get("source");
System.out.println("**onRequest: "+message.toString());
ArrayList frame = new ArrayList();
frame.add(jsonObject.get("type"));
frame.add(jsonObject.get("data"));
writeQueue.add(frame);
}
}
Related
first post here. I've tried to look for a question I have but no luck so I figure I ask it myself.
I am working on 2 programs. An Android app in Java and a C# Windows Form App on windows. They are both simply scorekeeping calculators to keep track of the score of 2 players.
The goal of the 2 programs is to use a Bluetooth connection to send data back and forth between each other so that they are "synced". Android app is a client, c# app is a server (32feet library).
Using the Bluetooth Chat example on Android and some code i put together in VS, I managed to get the 2 programs to connect and send and receive data to each other, great!
But now my main goal is that I need to find out a way to take the incoming data coming from the Android app and change the appropriate labels/text on the windows app.
So for example:
on the Windows App, there are 2 Labels: one for Player1, one for Player2 that both say "10".
On the Android App, I have 2 buttons that separately subtract from either Player1 or Player2's score.
On the android app, if I touch the button that subtracts(-) 1 from Player1 it would be 9. I now want that change to apply to Player1's score label on the windows app, where it would also show 9.
I then want the same thing for Player2's score.
This is the best I can describe my goal, and I would like to know if it's possible, and if so, be pointed in the right direction.
Here is some provided code for what I have so far:
C# windows form app:
private void button1_Click(object sender, EventArgs e)
{
if (serverStarted == true)
{
updateUI("Server already started");
return;
}
if (radioButton1.Checked)
{
connectAsClient();
}
else
{
connectAsServer();
}
}
private void connectAsServer()
{
Thread bluetoothServerThread = new Thread(new ThreadStart(ServerConnectThread)); //creates new thread and runs "ServerConnectThread"
bluetoothServerThread.Start();
}
private void connectAsClient()
{
throw new NotImplementedException();
}
Guid mUUID = new Guid("fa87c0d0-afac-11de-8a39-0800200c9a66");
bool serverStarted = false;
public void ServerConnectThread()
{
serverStarted = true;
updateUI("Server started, waiting for client");
BluetoothListener blueListener = new BluetoothListener(mUUID);
blueListener.Start();
BluetoothClient conn = blueListener.AcceptBluetoothClient();
updateUI("Client has connected");
Stream mStream = conn.GetStream();
while (true)
{
try
{
//handle server connection
byte[] received = new byte[1024];
mStream.Read(received, 0, received.Length);
updateUI("Received: " + Encoding.ASCII.GetString(received));
byte[] sent = Encoding.ASCII.GetBytes("hello world");
mStream.Write(sent, 0, sent.Length);
}
catch (IOException exception)
{
updateUI("Client disconnected");
}
}
}
private void updateUI(string message)
{
Func<int> del = delegate ()
{
textBox1.AppendText(message + Environment.NewLine);
return 0;
};
Invoke(del);
}
}
Android App (snippet from the Bluetooth Chat example - i think this is the only relevant part):
/**
* Sends a message.
*
* #param message A string of text to send.
*/
private void sendMessage(String message) {
// Check that we're actually connected before trying anything
if (mChatService.getState() != BluetoothChatService.STATE_CONNECTED) {
Toast.makeText(getActivity(), R.string.not_connected, Toast.LENGTH_SHORT).show();
return;
}
// Check that there's actually something to send
if (message.length() > 0) {
// Get the message bytes and tell the BluetoothChatService to write
byte[] send = message.getBytes();
mChatService.write(send);
// Reset out string buffer to zero and clear the edit text field
mOutStringBuffer.setLength(0);
mOutEditText.setText(mOutStringBuffer);
}
}
You will want to have to add the clients to alist of streams for reference and also store the scores of each client on a list and then send the data coming from each client to the rest of the clients
so from the server youd have basically something like this
List<Stream> clients=new List<Stream>();
List<String> client_scores=new List<String>();
public void ServerConnectThread()
{
serverStarted = true;
updateUI("Server started, waiting for client");
BluetoothListener blueListener = new BluetoothListener(mUUID);
blueListener.Start();
BluetoothClient conn = blueListener.AcceptBluetoothClient();
updateUI("Client has connected");
Stream mStream = conn.GetStream();
clients.add(mStream);
client_scores.add(new Random().Next()+"");
int index_cnt = clients.IndexOf(mStream);
while (true)
{
try
{
//handle server connection
byte[] received = new byte[1024];
mStream.Read(received, 0, received.Length);
updateUI("Received: " + Encoding.ASCII.GetString(received));
client_scores[client_scores.FindIndex(ind=>ind.Equals(index_cnt))] = Encoding.ASCII.GetString(received);
byte[] sent = Encoding.ASCII.GetBytes("hello world");
mStream.Write(sent, 0, sent.Length);
foreach(Stream str in clients)
{
byte[] my_score = Encoding.ASCII.GetBytes(clients.ToArray()[index_cnt]+"");
str.Write(my_score, 0, my_score.Length);
}
}
catch (IOException exception)
{
updateUI("Client disconnected");
}
}
}
You can then serialize the data being sent in some sort of json so as to send multiple fields of data comfortably for example :
{
"data type": "score",
"source_id": "client_unique_id",
"data": "200"
}
On your displaying side,just get the values of (in our example case source_id and data) and display on a label
I have an Android project where I'm using java mail for receiving mails from a gmail account.
First, I implemented a class for handling the receiving of mails. I know, each mail has its own
type of content (String, MultiPart, ...). I'm only interested in mails with a content type of String.
Ok, so I instantiate my receiving class, call the receiving method and get all mails from my gmail account with a content type of String.
So far, so good. This works for me perfectly.
But, when I create an Android module (.aar file) from the receiving class (same code, no changes) and import it to another Android project, there is a strange behavior of receiving mails.
After I imported the Android module, I instantiate the receiving class, call the receiving method, I get the same mails as before, but now they have
a content type of QPDecoderStream.
For a better understanding, here is my receiving code:
public List<Mail> receive() {
List<Mail> mailList = new ArrayList<>();
try {
Properties properties = new Properties();
properties.setProperty("mail.store.protocol", mConfig.getStoreProtocol());
Session session = Session.getInstance(properties, null);
mStore = session.getStore();
mStore.connect(mConfig.getImapHost(), mUsername, mPassword);
mInbox = mStore.getFolder(mConfig.getStoreFolder());
mInbox.open(Folder.READ_ONLY);
Message[] messages = mInbox.getMessages();
for (Message message : messages) {
String bodyPart = "";
Object content = message.getContent();
// Check for mail content type
if (content instanceof String) {
// This code is executed by "normal" method call within an Android class
Logger.info(MailReceiver.class, "Mail content is String");
bodyPart = (String) content;
} else if (content instanceof QPDecoderStream) {
// This code is executed by method call within an Android module
Logger.info(MailReceiver.class, "Mail content is QPDecoderStream");
BufferedInputStream in = new BufferedInputStream((InputStream) content);
ByteArrayOutputStream out = new ByteArrayOutputStream();
int c;
while ((c = in.read()) != -1) {
out.write(c);
}
bodyPart = new String(out.toByteArray());
}
Mail mail = new Mail();
mail.setSubject(message.getSubject());
mail.setDate(message.getSentDate().toString());
mail.setContent(bodyPart);
mailList.add(mail);
}
} catch (Exception e) {
Logger.error(MailReceiver.class, "Exception occurred while receiving mail: " + e.getMessage());
} finally {
closeInbox();
closeStore();
}
return mailList;
}
I hope I could explain my problem sufficiently and I would be glad for some advices.
Thanks in advance.
Chris P.
Ï am Taking data From server written in "C" using Sockets .
My java class name is ReceivingData, and here's the code for receiving the data and storing it in ArrayList and passing the ArrayList to other Class's Constructor.
package pack.exp;
import java.io.InputStream;
import java.net.Socket;
import java.util.ArrayList;
import java.util.List;
public class ReceivingData implements Runnable
{
public static void main(String[] args)
{
Thread t = new Thread(new ReceivingData());
t.start();
}
public List<String> obj1;
#Override
public void run()
{
Socket s;
InputStream stream;
try
{
s = new Socket("10.9.211.22", 6870);
stream = s.getInputStream();
byte[] data = new byte[13];
int read;
String can_Id= null;
while((read = stream.read(data)) != -1)
{
String can_Data=
String.format("%02X:%02X:%02X:%02X,
data[0], data[1], data[2], data[3]);
List<String> obj1= new ArrayList<String>();
obj1.add(can_Data.substring(0, 2));
obj1.add(can_Data.substring(3, 5));
obj1.add(can_Data.substring(6, 8));
obj1.add(can_Data.substring(9, 11));
Receiving_At_Regular_IntervalServlet rari= new
Receiving_At_Regular_IntervalServlet(obj1);
Thread.sleep(3000);
}
}
catch (Exception e)
{
e.printStackTrace();
}
}
}
This is the Servlet which is receiving the data from ArrayList passed by the above File.
and storing this data from the arraylist in to the Entity for datastore and deploys it on the Google App engine.
package pack.exp;
#SuppressWarnings("serial")
public class Receiving_At_Regular_IntervalServlet extends HttpServlet
{
List<String> obj2= new ArrayList<String>();
public Receiving_At_Regular_IntervalServlet(List<String> obj2) throws
IOException
{
this.obj2= obj2;
System.out.println("Receiving in Web Project" + obj2);
System.out.println("");
System.out.println("");
}
public void doGet(HttpServletRequest req, HttpServletResponse resp) throws
IOException
{
Key k1 = KeyFactory.createKey("C","0D F0 0800 1");
String parameter1 = obj2.get(0);
Entity can1 = new Entity(k1);
can1.setProperty("First Parameter", parameter1);
DatastoreService datastore = DatastoreServiceFactory.getDatastoreService();
datastore.put(can1);
Entity can11 = null;
try
{
can11= datastore.get(k1);
}
catch (EntityNotFoundException e)
{
e.printStackTrace();
}
String first_P= (String) can11.getProperty("First Parameter");
resp.setContentType("text/plain");
resp.getWriter().println("Parameter--- " + first_P);
}
}
The ReceivingData code evidently runs a thread and reads data from 10.9.211.22 port 6870 using Socket from a local computer. That's fine. It converts four bytes to a List and passes that to Receiving_At_Regular_IntervalServlet. Fine but not what you need.
This part might work on a development computer but won't work if deployed to the cloud. AppEngine servers does not permit developers to define main(), use Socket or communicate with private IP subnet 10. Forget about deploying that code to AppEngine.
Receiving_At_Regular_IntervalServlet has a custom constructor. AppEngine does not call your constructor because its servlet code expects only the default constructor. That is probably when your 503 error occurs.
With servlets the data is not supposed to come in via a constructor. Data must come in via members of the request parameter of the doGet method (though to be RESTful you should rather use doPut in this example). You insert the data into the request parameter but sending a correctly constructed http request to the server. Your code lacks that web application design.
Build your main program and your AppEngine code in separate projects and make main talk to servlet using http.
HTTP ERROR 503 error
You can't help anything when a server throws this error. It is only thrown when a service from the server is unavailable.
You need explicit handling on such error codes, other than 200 OK, in the client app and appropriate message has to be shown or as the alternate requirement suggestion.
Refer to:
Status Code definitions
Java - 503 - SC_SERVICE_UNAVAILABLE
For jabber support i use library Smack. Android port asmack.
I have class SmackAPI which implements MessageListener interface and contains methods to connect, login, send message. In the same time this class contains method:
#Override
public void processMessage(Chat chat, Message message) {
String from = message.getFrom();
String body = message.getBody();
System.out.println(String.format("Received message '%1$s' from %2$s", body, from));
this.recievedMessage = message;
}
It provides by MessageListener interface. All new messages processed by this method.
I write jabber plugin to connect, login, send message from phonegap.
My question: how i can in javascript listen for new messages?
I did it. I dont know however it is right way, but it works!
Cordova plugin class:
public class SmackJabber extends CordovaPlugin {
public boolean execute(String action, JSONArray args, CallbackContext callbackContext) {
this.cbContext = callbackContext;
switch (action) {
case LISTEN_MESSAGE:
res = new PluginResult(PluginResult.Status.NO_RESULT);
res.setKeepCallback(true);
cordova.getThreadPool().execute(new Runnable() {
#Override
public void run() {
String callbackId = cbContext.getCallbackId();
while (true) {
String msg = getMsg();
if (msg != null) {
res = new PluginResult(PluginResult.Status.OK, msg);
res.setKeepCallback(true);
CallbackContext cb = new CallbackContext(callbackId, webView);
cb.sendPluginResult(res);
}
}
}
});
cbContext.sendPluginResult(res);
break;
And easy javascript. Just call plugin method:
window.plugins.smackJabber.listenMessage(function(result) {
alert(result)
}, function(error) {
alert(error)
}
);
Explanation:
I call plugin method "listenMessage" (calling "execute" method with action "LISTEN_MESSAGE"). There i start thread from cordova threadpool with runnable, in runnable i got recursive function which check message. But before start runnable i have to take callbackId of method who call method execute. Also, for exit from method, i create new PluginResult with status "NO_RESULT" and set it option "keepCallback" to true - it means, that method calls in javascript awaiting one more callback result from me. When i got message, i create new callbackcontext based on callbackid and my webview, do setKeepCallback to true for futher possible responses for pluginresult, putting in pluginresult my message with status "OK" and sending it to callbackcontext. That's all.
I have implemented webservice client in axis2-1.6.2 in java and I get response when I call first time and for subsequent second time I get below error
java.lang.NullPointerException
at org.apache.axis2.client.OperationClient.prepareMessageContext(OperationClient.java:293)
at org.apache.axis2.description.OutInAxisOperationClient.executeImpl(OutInAxisOperation.java:180)
at org.apache.axis2.client.OperationClient.execute(OperationClient.java:165)
at org.apache.axis2.ccws.CustomerCareServiceStub.subscriberRetrieveLite(CustomerCareServiceStub.java:2380)
at Prepost.SubscriberRetrieveBalance.subscriberRetrieveLite(SubscriberRetrieveBalance.java:111)
at Prepost.CheckUser.doGet(CheckUser.java:149)
here is the API implementation class constructor which sets unique parameter which is same for all requests
public SubscriberRetrieveBalance(String url, String strCON_TimeOut, String strSO_TimeOut) {
try {
this.url = url;
stub = new CustomerCareServiceStub(url);
ServiceClient sClient = stub._getServiceClient();
Options options = sClient.getOptions();
options.setProperty(HTTPConstants.REUSE_HTTP_CLIENT, Constants.VALUE_TRUE);
options.setProperty(AddressingConstants.WS_ADDRESSING_VERSION, AddressingConstants.Submission.WSA_NAMESPACE);
//options.setTimeOutInMilliSeconds(2000);
TransportInDescription transportIn = new TransportInDescription("HTTP");
options.setTransportIn(transportIn);
options.setProperty(HTTPConstants.SO_TIMEOUT, Integer.parseInt(strSO_TimeOut));
options.setProperty(HTTPConstants.CONNECTION_TIMEOUT, Integer.parseInt(strCON_TimeOut));
sClient.setOptions(options);
} catch (Exception e) {
if (e.getMessage().equals("Can not find the external id")) {
System.out.println("Exception ::" + e.getMessage());
}
}
}
and it is called in a servlet and for performance issue I make object of this class for different-2 states(urls) and saved these object to hashmap when first request comes for respective states then make new object and use that object for subsequent requests for that state
SubscriberRetrieveBalance objBal = null;
BalanceBean bal = new BalanceBean();
if (mapObj.isEmpty() || (mapObj.get(strIP) == null)) {
objBal = new SubscriberRetrieveBalance(url, strCON_TimeOut, strSO_TimeOut);
mapObj.put(strIP, objBal);
} else {
objBal = mapObj.get(strIP);
}
bal = objBal.subscriberRetrieveLite(strMsisdn, userId, token, strCircleId, strCircleName, strSessionId, strDlgId);
first time it gives response and then gives nullpointer exception and above error for all requests that belongs to that state
This code is working fine with axis2-1.5
Is there any change in axis2-1.6.2 version that every time it needs new object of API implemented class
Please suggest.