I am trying to use TooTallNate's Java-Websocket to connect to OkCoin. I found this simple code example somewhere, but I can't get it to work. The connection is immediately closed and so the call mWs.send(...) throws a WebsocketNotConnectedException. I can't figure out why; so far I have found a number of similar questions, none of which have an answer.
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.handshake.ServerHandshake;
import org.json.JSONObject;
import java.net.URI;
import java.net.URISyntaxException;
public class TestApp {
public static void main(String[] args) {
try {
URI uri = new URI("wss://real.okcoin.cn:10440/websocket/okcoinapi");
final WebSocketClient mWs = new WebSocketClient(uri) {
#Override
public void onMessage(String message) {
JSONObject obj = new JSONObject(message);
}
#Override
public void onOpen(ServerHandshake handshake) {
System.out.println("opened connection");
}
#Override
public void onClose(int code, String reason, boolean remote) {
System.out.println("closed connection");
}
#Override
public void onError(Exception ex) {
ex.printStackTrace();
}
};
mWs.connect();
JSONObject obj = new JSONObject();
obj.put("event", "addChannel");
obj.put("channel", "ok_btccny_ticker");
mWs.send(obj.toString());
} catch (URISyntaxException e) {
System.err.println("URI not formatted correctly");
}
}
}
Use mWs.connectBlocking() instead of mWs.connect() with this it will not close automatically.
See
Related
In my Spring project I'm using websocket client (org.java_websocket.client.WebSocketClient) It's worked as fine, main problem is in my code I can to get result with onMessage method but it's Asyc and I need result in Sync caller, other websocket clients are similar behavior too
Async is basically working concept in websocket
import java.util.Collections;
import java.util.concurrent.ExecutionException;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.ByteBuffer;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.drafts.Draft_6455;
import org.java_websocket.extensions.IExtension;
import org.java_websocket.handshake.ServerHandshake;
import org.java_websocket.protocols.IProtocol;
import org.java_websocket.protocols.Protocol;
public class EmptyClient extends WebSocketClient {
private final static Draft_6455 draft = new Draft_6455(Collections.<IExtension>emptyList(), Collections.<IProtocol>singletonList(new Protocol("my-protocol")));
private String request = null, response = null;
public EmptyClient(String serverUri, String request) throws URISyntaxException {
super(new URI(serverUri), draft);
this.request = request;
setConnectionLostTimeout(3000);
connect();
}
#Override
public void onOpen(ServerHandshake handshakedata) {
send(request);
System.out.println("new connection opened");
}
#Override
public void onClose(int code, String reason, boolean remote) {
System.out.println("closed with exit code " + code + " additional info: " + reason + " remote:" + remote);
}
#Override
public void onMessage(String message) {
this.response = message;
close();
}
#Override
public void onMessage(ByteBuffer message) {
System.out.println("received ByteBuffer");
}
#Override
public void onError(Exception ex) {
System.err.println("an error occurred:" + ex);
}
public String getResponse() {
return response;
}
public static void main(String[] args) throws URISyntaxException, ExecutionException, InterruptedException {
String res = new EmptyClient("ws://123.abc:8888/", "{\"command\":\"create\",\"id\":\"1234\"}").getResponse();
System.out.println("response : "+res);
}
}
at the frist I think I could to use Future<T> and ExecutorService but main problem is Future itself is Async and result by onMessage method is Async too
let me to show you how is changed my previous code :
import java.util.Collections;
import java.util.concurrent.ExecutionException;
import java.net.URI;
import java.net.URISyntaxException;
import java.nio.ByteBuffer;
import org.java_websocket.client.WebSocketClient;
import org.java_websocket.drafts.Draft_6455;
import org.java_websocket.extensions.IExtension;
import org.java_websocket.handshake.ServerHandshake;
import org.java_websocket.protocols.IProtocol;
import org.java_websocket.protocols.Protocol;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
public class EmptyClient extends WebSocketClient {
private final static Draft_6455 draft = new Draft_6455(Collections.<IExtension>emptyList(), Collections.<IProtocol>singletonList(new Protocol("my-protocol")));
private String request = null, response = null;
private ExecutorService executor = Executors.newSingleThreadExecutor();
public EmptyClient(String serverUri, String request) throws URISyntaxException {
super(new URI(serverUri), draft);
this.request = request;
setConnectionLostTimeout(3000);
connect();
}
#Override
public void onOpen(ServerHandshake handshakedata) {
send(request);
System.out.println("new connection opened");
}
#Override
public void onClose(int code, String reason, boolean remote) {
System.out.println("closed with exit code " + code + " additional info: " + reason + " remote:" + remote);
executor.shutdown();
}
#Override
public void onMessage(String message) {
this.response = message;
close();
}
#Override
public void onMessage(ByteBuffer message) {
System.out.println("received ByteBuffer");
}
#Override
public void onError(Exception ex) {
System.err.println("an error occurred:" + ex);
}
public Future<String> getResponse() {
return executor.submit(() -> {
return response;
});
}
public static void main(String[] args) throws URISyntaxException, ExecutionException, InterruptedException {
Future<String> res = new EmptyClient("ws://123.abc:8888/", "{\"command\":\"create\",\"id\":\"1234\"}").getResponse();
System.out.println(res.isDone() + res.get());
}
}
I can not to use Future as return type of onMessage method because it's belong to WebSocketClient class that I used
we know by get method from Future class is right way to get result, if any method by Furter was exist that I could to call it in onMessage method when response is exposed then get method returned actual Furtur<String> Object but there is nothing to do, maybe another concurrency class or mixed technique are better to use
hence I call EmptyClient class in sync method and I need that result to produce something else, how can I to resolve it ? maybe other Concurrency API classes and or locker is there to use
I'm new to Netty and I wrote based on an example I found a Netty http server, that keeps http connections open to send server-sent-events to the browser client.
Problem is that it only accepts up to about ~5 connections and after that blocks new connections. I googled and found most answers said to set SO_LOGBACK to a higher value. Tried different values and while I saw no difference. I even set it to MAX_INTEGER value and still had only 5 connections.
Server code (Using Netty version 4.1.6.Final):
package server;
import static io.netty.buffer.Unpooled.copiedBuffer;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelOption;
import io.netty.channel.EventLoopGroup;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.http.DefaultFullHttpResponse;
import io.netty.handler.codec.http.FullHttpResponse;
import io.netty.handler.codec.http.HttpHeaders;
import io.netty.handler.codec.http.HttpObjectAggregator;
import io.netty.handler.codec.http.HttpResponseStatus;
import io.netty.handler.codec.http.HttpServerCodec;
import io.netty.handler.codec.http.HttpVersion;
public class NettyHttpServer {
private ChannelFuture channel;
private final EventLoopGroup masterGroup;
public NettyHttpServer() {
masterGroup = new NioEventLoopGroup(100);
}
public void start() {
try {
final ServerBootstrap bootstrap = new ServerBootstrap().group(masterGroup)
.channel(NioServerSocketChannel.class).childHandler(new ChannelInitializer < SocketChannel > () {
#Override
public void initChannel(final SocketChannel ch) throws Exception {
ch.pipeline().addLast("codec", new HttpServerCodec());
ch.pipeline().addLast("aggregator", new HttpObjectAggregator(512 * 1024));
ch.pipeline().addLast("request", new ChannelInboundHandlerAdapter() {
#Override
public void channelRead(final ChannelHandlerContext ctx, final Object msg)
throws Exception {
System.out.println(msg);
registerToPubSub(ctx, msg);
}
#Override
public void channelReadComplete(ChannelHandlerContext ctx) throws Exception {
ctx.flush();
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
ctx.writeAndFlush(new DefaultFullHttpResponse(HttpVersion.HTTP_1_1,
HttpResponseStatus.INTERNAL_SERVER_ERROR,
copiedBuffer(cause.getMessage().getBytes())));
}
});
}
}).option(ChannelOption.SO_BACKLOG, Integer.MAX_VALUE)
.childOption(ChannelOption.SO_KEEPALIVE, true);
channel = bootstrap.bind(8081).sync();
// channels.add(bootstrap.bind(8080).sync());
} catch (final InterruptedException e) {}
}
public void shutdown() {
masterGroup.shutdownGracefully();
try {
channel.channel().closeFuture().sync();
} catch (InterruptedException e) {}
}
private void registerToPubSub(final ChannelHandlerContext ctx, Object msg) {
new Thread() {
#Override
public void run() {
while (true) {
final String responseMessage = "data:abcdef\n\n";
FullHttpResponse response = new DefaultFullHttpResponse(HttpVersion.HTTP_1_1, HttpResponseStatus.OK,
copiedBuffer(responseMessage.getBytes()));
response.headers().set(HttpHeaders.Names.CONNECTION, HttpHeaders.Values.KEEP_ALIVE);
response.headers().set(HttpHeaders.Names.CONTENT_TYPE, "text/event-stream");
response.headers().set(HttpHeaders.Names.ACCESS_CONTROL_ALLOW_ORIGIN, "*");
response.headers().set("Cache-Control", "no-cache");
ctx.writeAndFlush(response);
try {
Thread.sleep(1000);
} catch (InterruptedException e) {
e.printStackTrace();
}
}
};
}.start();
}
public static void main(String[] args) {
new NettyHttpServer().start();
}
}
Client js code (I run it more than 5 times from my browser in different tabs, and the not all of them get:
var source = new EventSource("http://localhost:8081");
source.onmessage = function(event) {
console.log(event.data);
};
source.onerror= function(err){console.log(err); source.close()};
source.onopen = function(event){console.log('open'); console.log(event)}
You need to let the browser know that you are done sending the response, and for that you have three options.
Set a content length
Send it chunked
Close the connection when you are done
You aren't doing any of those. I suspect your browser is still waiting for the full response to each request you send, and is using a new connection for each request in your testing. After 5 requests your browser must be refusing to create new connections.
Another thing I noticed is that you are creating a new thread for each request in your server, and never letting it die. That will cause problems down the line as you try to scale. If you really want that code to run in a different thread then I suggest looking at overloaded methods for adding handlers to the pipeline; those should let you specify a thread pool to run them in.
Once the websocket session has been established, is it possible to pass data other than using session.getAsyncRemote().sendText(**)) across the session?
I am using
javax.websocket.* as ClientEndpoint
and spring-websocket for server.
I have tried using:
session.getRequestParameterMap().putAll(bMap); //This gives me exception
session.getPathParameters().putAll(aMap); //This gives me exception
session.getUserProperties().put("dataE", "dataF");; //This goes through fine
And I am not able to see the data on server side:
Map<String, Object> aMap = stStandard.getNativeSession().getUserProperties();
This map comes as blank on server side.Please let me know if more information is needed. Here is my code:
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import javax.websocket.ClientEndpoint;
import javax.websocket.OnClose;
import javax.websocket.OnMessage;
import javax.websocket.OnOpen;
import javax.websocket.Session;
#ClientEndpoint
public class TestSpring {
#OnMessage
public void onMessage(String message, Session session) throws IOException,
InterruptedException {
Map aMap = new HashMap();
aMap.put("dataA", "dataB");
try {
session.getPathParameters().putAll(aMap);
} catch (Exception e) {
e.printStackTrace();
}
Map bMap = new HashMap();
List<String> bList = new ArrayList<String>();
bList.add("dataC");
try {
bMap.put("dataD", bList);
session.getRequestParameterMap().putAll(bMap);
} catch (Exception e) {
e.printStackTrace();
}
try {
session.getUserProperties().put("dataE", "dataF");
} catch (Exception e) {
e.printStackTrace();
}
session.getAsyncRemote().sendText("Data to be sent");
}
#OnOpen
public void onOpen() {
System.out.println("Client connected");
}
#OnClose
public void onClose() {
System.out.println("Connection closed");
}
}
import java.util.List;
import java.util.Map;
import org.springframework.web.socket.BinaryMessage;
import org.springframework.web.socket.TextMessage;
import org.springframework.web.socket.WebSocketExtension;
import org.springframework.web.socket.WebSocketSession;
import org.springframework.web.socket.adapter.standard.StandardWebSocketSession;
import org.springframework.web.socket.handler.AbstractWebSocketHandler;
import com.sap.websocket.inMemoryWebSockets.KeepInMemoryWebSockets;
public class WebsocketEndPoint extends AbstractWebSocketHandler {
#Override
protected void handleTextMessage(WebSocketSession session,
TextMessage message) throws Exception {
session.getHandshakeHeaders();
StandardWebSocketSession stStandard = (StandardWebSocketSession) session;
try {
Map<String, Object> aMap = stStandard.getNativeSession()
.getUserProperties();
} catch (Exception e) {
e.printStackTrace();
}
TextMessage binaryMessage = new TextMessage(new String(
"Hello Client. This is message sent from server"));
session.sendMessage(binaryMessage);
}
#Override
protected void handleBinaryMessage(WebSocketSession session,
BinaryMessage message) throws Exception {
}
}
We are using Websockets from the Grizzly project and had expected that the implementation would allow multiple incoming messages over a connection to be processed at the same time. It appears that this is not the case or there is a configuration step that we have missed. To validate this I have created a modified echo test that delays in the onMessage after echoing the text. When a client sends multiple messages over the same connection the server always blocks until onMessage completes before processing a subsequent message. Is this the expected functionality?
The simplified server code is as follows:
package com.grorange.samples.echo;
import java.util.concurrent.atomic.AtomicBoolean;
import org.glassfish.grizzly.http.server.HttpServer;
import org.glassfish.grizzly.http.server.NetworkListener;
import org.glassfish.grizzly.websockets.DataFrame;
import org.glassfish.grizzly.websockets.WebSocket;
import org.glassfish.grizzly.websockets.WebSocketAddOn;
import org.glassfish.grizzly.websockets.WebSocketApplication;
import org.glassfish.grizzly.websockets.WebSocketEngine;
public class Echo extends WebSocketApplication {
private final AtomicBoolean inMessage = new AtomicBoolean(false);
#Override
public void onClose(WebSocket socket, DataFrame frame) {
super.onClose(socket, frame);
System.out.println("Disconnected!");
}
#Override
public void onConnect(WebSocket socket) {
System.out.println("Connected!");
}
#Override
public void onMessage(WebSocket socket, String text) {
System.out.println("Server: " + text);
socket.send(text);
if (this.inMessage.compareAndSet(false, true)) {
try {
Thread.sleep(10000);
} catch (Exception e) {}
this.inMessage.set(false);
}
}
#Override
public void onMessage(WebSocket socket, byte[] bytes) {
socket.send(bytes);
if (this.inMessage.compareAndSet(false, true)) {
try {
Thread.sleep(Long.MAX_VALUE);
} catch (Exception e) {}
this.inMessage.set(false);
}
}
public static void main(String[] args) throws Exception {
HttpServer server = HttpServer.createSimpleServer("http://0.0.0.0", 8083);
WebSocketAddOn addOn = new WebSocketAddOn();
addOn.setTimeoutInSeconds(60);
for (NetworkListener listener : server.getListeners()) {
listener.registerAddOn(addOn);
}
WebSocketEngine.getEngine().register("", "/Echo", new Echo());
server.start();
Thread.sleep(Long.MAX_VALUE);
}
}
The simplified client code is:
Yes, it's expected.
The way to go is to pass message processing, inside onMessage, to a different thread.
I have a kryonet client/server that work find.. well mostly. The client remains idle and eventually disconnects after awhile but thats not the issue i'm trying to solve currently. Currently, the server and client can establish a connection and send data back and forth(Before the client times out) as long as the client and server are on the same computer. If you try to connect to a different computer on the LAN the connection times out and fails.
So here's my question(s):
What would be a possible cause for the connection issue?
What is the proper way to keep a client alive? ( secondary goal but if you know it, that'd be great)
*I'm using LibGDX and Kryonet for this. As far as I know, they shouldn't have any conflicts.
Server:
package com.me.mygdxgame;
import java.io.IOException;
import java.util.ArrayList;
import com.badlogic.gdx.math.Vector2;
import com.esotericsoftware.kryonet.Connection;
import com.esotericsoftware.kryonet.Listener;
import com.esotericsoftware.kryonet.Server;
import com.me.mygdxgame.Network.Obstacles;
public class GameServer {
Server server;
public GameServer () throws IOException {
server = new Server() {
protected Connection newConnection () {
return new PlayerConnection();
}
};
Network.register(server);
//Sends Stuff to Client
server.addListener(new Listener() {
public void received (Connection c, Object object) {
PlayerConnection connection = (PlayerConnection)c;
if (object instanceof Obstacles) {
if (connection.name != null) return;
ArrayList<Vector2> obs = ((Obstacles)object).obstacles;
if (obs == null) return;
System.out.println("Obstacles recieved.");
for(int i = 0; i < obs.size(); i++)
System.out.println("Obstacle " + i + "- x: " + obs.get(i).x );
return;
}
}
});
server.bind(Network.port);
server.start();
}
public void sendAll () { //Send out data
Obstacles ob = new Obstacles();
ob.obstacles = new ArrayList<Vector2>();
for(int i =0; i < Map.obstacles.size(); i++){
ob.obstacles.add(new Vector2(Map.obstacles.get(i).x,Map.obstacles.get(i).y));
}
server.sendToAllTCP(ob);
}
static class PlayerConnection extends Connection {
public String name;
}
}
Client:
package com.me.mygdxgame;
import java.awt.EventQueue;
import java.io.IOException;
import java.net.Inet4Address;
import java.net.InetAddress;
import java.net.UnknownHostException;
import java.util.ArrayList;
import com.badlogic.gdx.ApplicationListener;
import com.esotericsoftware.kryonet.Client;
import com.esotericsoftware.kryonet.Connection;
import com.esotericsoftware.kryonet.Listener;
import com.me.mygdxgame.Network.Obstacles;
public class GameClient implements ApplicationListener{
Client client;
String name;
String RefreshHost;
boolean Connected = false;
ArrayList<String> hosts = new ArrayList<String>();
public static String host;
public GameClient (String host) {
client = new Client();
client.start();
this.host = host;
Network.register(client);
client.addListener(new Listener() {
public void connected (Connection connection) {
System.out.println("connected");
Connected = true;
}
public void received (Connection connection, Object object) {
if (object instanceof Obstacles) {
Obstacles obs = (Obstacles)object;
System.out.println("Obstacle recieved on client - " + obs.obstacles.size());
client.sendTCP(obs);
System.out.println("Obstacles sent back.");
return;
}else {
System.out.println("invalid packet");
}
}
public void disconnected (Connection connection) {
EventQueue.invokeLater(new Runnable() {
public void run () {
System.out.println("closed");
Connected = false;
client.close();
}
});
}
});
new Thread("Connect") {
public void run () {
try {
client.connect(5000, GameClient.host, Network.port);
System.out.println("Connected!");
client.setKeepAliveTCP(NORM_PRIORITY);
while(Connected) {
//System.out.println(client.isIdle());
}
client.run();
} catch (IOException ex) {
ex.printStackTrace();
}
}
}.start();
}
#Override
public void create() {
// TODO Auto-generated method stub
}
#Override
public void resize(int width, int height) {
// TODO Auto-generated method stub
}
#Override
public void render() {
// TODO Auto-generated method stub
}
#Override
public void pause() {
// TODO Auto-generated method stub
}
#Override
public void resume() {
// TODO Auto-generated method stub
}
#Override
public void dispose() {
// TODO Auto-generated method stub
}
}
I suggest you set the host BEFORE you start the client
public GameClient (String host) {
client = new Client();
this.host = host;
client.start();
I am not familiar with kryonet Client, but it makes sense to do it that way.
Generally make sure that your client is trying to connect to the host that you have server running on...
One possible cause for such connection issue is a firewall blocking your Network.port
Another one, sorry but I have to ask: Is the server-app running in the other machine?
I ask because I dont'see a main function in your server code
public static void main(String[] args) throws IOException {
Log.set(Log.LEVEL_DEBUG);
new GameServer();
}
I use to get running my server-app with this terminal command
java -jar myserverfile.jar
How do you get it running in the "remote" machine?
By the way, I am using libgdx and kryonet for my game and so far I haven't get issues using them together.
In my case I have the server in a AWS instance listening for game-client testing from my computer.