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Spring Integration : No publisher available to publish TCP Connection related events

I am using Spring Integration with Spring Boot. I have a TCP Client [TcpNetClientConnectionFactory] with TcpOutboundGateway setup. I can see the below warnings in Production[No publisher available to publish].
Log Snippet
Based on my checking this warning is shown when the org.springframework.context.ApplicationEventPublisher is null.
Code:
#Bean
#ServiceActivator(inputChannel = "a04A08OutgoingChannel")
public MessageHandler a04A08OutgoingGate() {
final TcpOutboundGateway gate = new TcpOutboundGateway();
// Connection configured in client mode to send the message over the TCP socket
// and wait for acknowledgement
gate.setConnectionFactory(connectionFactory.connectionFactory(host, port));
gate.setReplyChannelName("a04A08ReplyToString");
gate.setRemoteTimeout(60_000);
return gate;
}
#Transformer(inputChannel = "a04A08ReplyToString")
public String transform(byte[] bytes) {
String reply = new String(bytes);
log.debug("transform - a04A08ReplyToString channel " + reply);
return new String(bytes);
}
public String outgoingMessage(String message) {
String reply = null;
log.info("Message being Sent : " + message);
try {
// Send the message to the TCP socket and wait for acknowledgement
reply = a04a08OutgoingGateway.sendMessage(message);
} catch (ConnectException e) {
log.error(e.getMessage(),e);
}
log.info("Acknowledgement received : " + reply);
return reply;
}
ConnectionFactory.java:
public AbstractClientConnectionFactory connectionFactory(String host, int port) {
final AbstractClientConnectionFactory connectionFactory = new TcpNetClientConnectionFactory(host, port);
connectionFactory.setSerializer(customDeserializer);
connectionFactory.setDeserializer(customDeserializer);
//connectionFactory.setSoKeepAlive(true);
connectionFactory.setSingleUse(true);// This property when set to false ensures that one shared connection is used for all
// request/replies and each caller blocks waiting for the socket
return connectionFactory;
}
Edit 1 : Included CustomDeserializer.java
#Override
public void serialize(String object, OutputStream outputStream) throws IOException {
log.info("[Serialize] Serializing data : length ==> " + object.length());
outputStream.write(object.getBytes());
log.info("[Serialize] data posted to stream");
}
#Override
public byte[] deserialize(InputStream inputStream) throws IOException {
log.info("[Deserialize] De-Serializing data");
BufferedReader input = new BufferedReader(new InputStreamReader(inputStream));
StringBuffer stringbuffer = new StringBuffer();
while (true) {
int value = input.read();
if (value == 28) {
break;
} else {
if (value != -1) {
stringbuffer.append((char) value + "");
} else {
break;
}
}
}
log.info("[deserialize.readFromSocket()]: " + stringbuffer.toString());
return stringbuffer.toString().getBytes();
}
The TCP server is able to receive the messages sent by the TCP client. [Note: TCP server is a different system and not maintained by us].I have 2 queries.
Will this warning have any impact? Can anyone elaborate on the warning? Even when the warnings are seen the messages from TCP client are sent to TCP server without any issues.
We faced below issue (Caused by: org.springframework.messaging.MessagingException: Exception while awaiting reply; nested exception is java.net.SocketTimeoutException: Read timed out) in production recently. When we faced the below exception, telnet to the server port worked but the messages were not received by the server. The issue was automatically resolved when the TCP server was restarted. My question : Is this issue related to the warning in point #1. These warnings are seen even on normal days when the messages are sent to the server without any issues.
Error logs
P.S: I also checked the post : No publisher available to publish TcpConnectionOpenEvent / TcpConnectionCloseEvent

It is not related; sounds like a server problem if restarting it solves it.
The connection factory must be declared as a #Bean so that spring can inject the event publisher.

Phoenix channel.push not working on Android

I am trying to have chat in my application using Phoenix channels. I have a web client and and an Android client. Right now it is working correctly on the web. I am having an issue with the Android side.
It is able to receive messages pushed to the channel, but it wont send any out. When I try to push a message I get the following exceptions thrown:
java.net.SocketTimeoutException: timeout exception
java.lang.IllegalStateException: Another message writer is active. Did you call close()?
My chat channel
defmodule GoodApi2.ChatChannel do
use Phoenix.Channel
intercept(["chat_send"])
def join("chat:"<> _room_code, _message, socket) do
{:ok, socket}
end
def handle_in("chat_send", message, socket) do
broadcast! socket, "chat_send", message
{:noreply, socket}
end
def handle_out("chat_send", payload, socket) do
push socket, "new_message", payload
{:noreply, socket}
end
end
On the Android app creating the channel
try{
socket = new Socket("ws:"+ApiUtils.BASE.toString()+"socket/websocket");
socket.connect();
channel = socket.chan("chat:"+chatName, null);
channel.join()
.receive("ok", new IMessageCallback() {
#Override
public void onMessage(Envelope envelope) {
System.out.println("IGNORE");
}
});
}
catch (IOException e) {
System.out.println("error connecting to chat");
e.printStackTrace();
}
On the Android app pushing to the channel
public void sendMessage(final String message){
ObjectNode node = new ObjectNode(JsonNodeFactory.instance)
.put("sender", email)
.put("sender_name", userName)
.put("content", message);
try{
channel.push("chat_send", node);
}
catch (Exception e){
Log.e("message failed to send", message);
}
}

How to let netty channel.writeAndFlush() throws Exceptions when no TCP ACK response

I am developing an IM server with the Netty4 frame. Meanwhile I used the method named channel.writeAndFlush() to send messages to the client. However, when the socket of the client on the mobile phone shutting down unusually such as turning off the network connections or turning on the airplane mode on the device, the netty4 frame counld not find that the corresponding channel being inactive. Moreover, the ChannelGroupFuture returned by the writeAndFlush() method reports the sending result success with the method ChannelGroupFuture.isSuccess().
So, why the ChannelGroupFuture didn't return me the sending is failed without throwing any exception?
ChannelGroupFuture future = connectionService.sendMessageToUser(msgBase, toUid).sync();
future.addListeners(new ChannelGroupFutureListener(){
#Override
public void operationComplete(ChannelGroupFuture future)
throws Exception {
if(future.isDone() && future.isSuccess()){
chatMessageService.saveSentChatMessage(msgBase);
} else if(!future.isSuccess()){
chatMessageService.saveUnsentChatMessage(msgBase);
}
});
public ChannelGroupFuture writeAndFlush(Object message, ChannelMatcher matcher) {
if (message == null) {
throw new NullPointerException("message");
}
if (matcher == null) {
throw new NullPointerException("matcher");
}
if(matcher instanceof AttributeChannelMatcher){
Map<Channel, ChannelFuture> futures = new LinkedHashMap<Channel, ChannelFuture>(1);
AttributeChannelMatcher<T> attributeMatcher = (AttributeChannelMatcher<T>) matcher;
Channel c = nonServerChannelMap.get(attributeMatcher.getAttributeKeyValue());
futures.put(c, c.writeAndFlush(safeDuplicate(message)));
ReferenceCountUtil.release(message);
return new DefaultChannelGroupFuture(this, futures, executor);
}else{
Map<Channel, ChannelFuture> futures = new LinkedHashMap<Channel, ChannelFuture>(size());
for (Channel c : nonServerChannelMap.values()) {
if (matcher.matches(c)) {
futures.put(c, c.writeAndFlush(safeDuplicate(message)));
}
}
ReferenceCountUtil.release(message);
return new DefaultChannelGroupFuture(this, futures, executor);
}
}

You can't. TCP writes are asynchronous with respect to the application. They don't wait for ACKs before they return. There is a send buffer on the sending side and a receive buffer on the receiving side. All this means that it could take several writes and quite a few seconds before you detect a broken connection.

websocket send message from the server to all clients

I want to send a message to all active clients.
#OnMessage
public void onMessage(String message, Session session) {
switch (message) {
case "latencyEqualize":
for (Session otherSession : session.getOpenSessions()) {
RemoteEndpoint.Basic other = otherSession.getBasicRemote();
String data = "Max latency = "
+ LatencyEqualizer.getMaxLatency(latencies);
try {
other.sendText(data);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
break;
default:
RemoteEndpoint.Basic other = session.getBasicRemote();
try {
other.sendText(message);
} catch (IOException e) {
throw new RuntimeException(e);
}
}
}
Something is wrong with this code. When i send message "latencyEqualize" from the first client the server answers only to the same client. Other clients don't receive message "Max latency = 15". But when the second client sends to server any message, he recieves back "Max latency = 15". And all future calls to server return the message from previous call.
Is there a way to avoid this. I want all clients get "Max latency" message when one of them send "latencyEqualize" message to the server.

The reason why only one client receives your message is that session variable contains connection only of that client who sent you message.
To send your message to all clients, store their connections in some collection (for example, ArrayList<Session>) in onOpen() method, and then iterate though that collection to get connections of all of your clients

Reliable UDP Protocol Implementation in Java - Why does this happen?

I'm currently using a Java implementation of the Reliable UDP protocol, found here. The project has absolutely no tutorials so I have found it really hard to identify problems.
I have set up a client and server. The server runs on localhost:1234 and the client runs on localhost:1235. The server is first established, and loops listening for connections -
try {
ReliableSocket clientSocket = server.socket.accept();
InetSocketAddress clientAddress = (InetSocketAddress) clientSocket.getRemoteSocketAddress();
Logger.getLogger("ServerConnectionListener").info("New Connection from "+
clientAddress.getHostName()+":"+clientAddress.getPort()+" Processing...");
LessurConnectedClient client = new LessurConnectedClient(clientSocket);
ClientCommunicationSocketListener listener = new ClientCommunicationSocketListener(this, client);
clientSocket.addListener(listener);
} catch (Exception e) {
e.printStackTrace();
}
When a connection is established, it creates a listener for events on that socket -
class ClientCommunicationSocketListener implements ReliableSocketListener {
ServerConnectionListener connectionListener;
LessurConnectedClient client;
public ClientCommunicationSocketListener(ServerConnectionListener connectionListener, LessurConnectedClient client){
this.connectionListener = connectionListener;
this.client = client;
}
#Override
public void packetReceivedInOrder() {
connectionListener.server.handlePacket(client);
}
#Override
public void packetReceivedOutOfOrder() {
connectionListener.server.handlePacket(client);
}
}
When a packet is received, it passes it to server.handlePacket, which performs a debug routine of printing "Packet Received!".
My client connects to the server as so -
LessurClient client = new LessurClient();
InetSocketAddress a = (InetSocketAddress) server.getSocket().getLocalSocketAddress();
Logger.getLogger("client-connector").info("Trying to connect to server "+
a.getAddress().toString()+":"+
a.getPort());
client.connect(a.getAddress(), a.getPort());
// LessurClient.connect
public void connect(InetAddress address, int port){
try {
socket = new ReliableSocket(address, port, InetAddress.getLocalHost(), 1235);
isConnected = true;
Logger.getLogger("LessurClient").info("Connected to server "+address.getHostAddress()+":"+port);
} catch (IOException e) {
e.printStackTrace();
}
}
I have linked my code so when I press the key 'Z', it will send a packet to the server as so -
public void sendPacket(GamePacket packet){
if(!isConnected){
Logger.getLogger("LessurClient").severe("Can't send packet. Client is not connected to any server.");
return;
}
try {
OutputStream o = socket.getOutputStream();
o.write(packet.getData());
o.flush();
Logger.getLogger("LessurClient").info("Sending Packet with data \""+packet.getData()+"\" to server "+socket.getInetAddress().toString()+":"+socket.getPort());
} catch (IOException e) {
e.printStackTrace();
}
}
My problem is, after sending 32 packets, the server no longer receives packets, and after sending 64 packets, it crashes. I have investigated into the code, and it appears that its something associated with packets not being removed from the receive queue, as when I changed the _recvQueueSize variable in ReliableSocket.java:1815 from 32 to 40, I could now send 40 packets without something going wrong.
Could someone help me identify this issue? I've been looking at the code all day.

I managed to fix the problem.
You see, since this is an implementation of RUDP, it extends most of the Socket classes. Specifically, ReliableSocket.getInputStream(), was custom coded to a managed input stream. My problem was, I was receiving the packets, but not reading from the buffer.
When you receive a packet you're supposed to read from the buffer, otherwise the packet will not be dropped from the queue.
So all I had to do, was everytime I received a packet, read the size of the packet, and continue.