Netty 4.1.35.Final
我想与多个连接到Netty服务器的客户端建立持久的客户端-服务器连接，并且服务器将该消息广播到所有连接的客户端。
当第一个客户端连接到服务器时，它可以工作并处理消息。为了维持连接，客户端将发送ping消息，而服务器会接收这些消息。
第二个连接的客户端可以发送其消息，但是第一个连接不再起作用，并且仅接收到来自第二个客户端的ping消息。
我非常拼命，我们将不胜感激！
服务器：
package ch.zhaw.psit3.net.server;
import ch.zhaw.psit3.models.Document;
import ch.zhaw.psit3.models.Enums.ConnectionState;
import ch.zhaw.psit3.models.NetworkState;
import ch.zhaw.psit3.models.Session;
import ch.zhaw.psit3.net.common.MessageDecoder;
import ch.zhaw.psit3.net.common.MessageEncoder;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.*;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import java.io.IOException;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;
public class Server implements IServer, Runnable {
private final MessageBroadcaster broadcaster = new MessageBroadcaster();
private final int port;
private ServerListener listener;
private Executor executor;
private ServiceAdvertiser serviceAdvertiser;
private final NetworkState networkState = new NetworkState();
@Override
public void start(Document document) throws IOException {
/**
* Start advertising with https://github.com/jmdns/jmdns.
*/
executor = Executors.newFixedThreadPool(1);
executor.execute(this);
}
@Override
public void stop() {
}
private void initializeState() {
this.networkState.state = ConnectionState.NOT_CONNECTED;
this.networkState.activeSession = new Session();
}
@Override
public void setListener(ServerListener listener) {
/*todo reevaluate if data field listener in this is needed*/
this.listener = listener;
}
public static void main(String[] args) throws Exception {
int port = args.length > 0 ? Integer.parseInt(args[0]) : 9090;
Server server = new Server(port);
server.start(new Document());
}
public Server() {
this.port = 9090;
this.serviceAdvertiser = new ServiceAdvertiser(this.port);
initializeState();
}
public Server(final int port) {
this.port = port;
this.serviceAdvertiser = new ServiceAdvertiser(this.port);
initializeState();
}
@Override
public void run() {
/**
* This thread is meant to handle the ot process with one client.
* It has its own ot instance running and sends changes from the client back to the server, which distributes it to all other serverConnections
*
*/
if (!(Thread.currentThread() instanceof IServerConnection || !(Thread.currentThread() instanceof Executor))) {
throw new UnsupportedOperationException(Thread.currentThread().getName() + " thread is not allowed to call the run method");
}
EventLoopGroup bossGroup = new NioEventLoopGroup();
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap bootstrap = new ServerBootstrap();
bootstrap.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch)
throws Exception {
ch.pipeline().addLast("messageDecoder", new MessageDecoder());
ch.pipeline().addLast("messageEncoder", new MessageEncoder());
ch.pipeline().addLast("serverHandler", new ServerHandler(listener, broadcaster));
}
}).option(ChannelOption.SO_BACKLOG, 128)
.childOption(ChannelOption.SO_KEEPALIVE, true);
ChannelFuture future = bootstrap.bind(port).sync();
future.channel().closeFuture().sync();
} catch (InterruptedException ie) {
} finally {
workerGroup.shutdownGracefully();
bossGroup.shutdownGracefully();
}
}
}
ServerHandler：
package ch.zhaw.psit3.net.server;
import ch.zhaw.psit3.models.Message;
import io.netty.channel.*;
import java.util.Objects;
public class ServerHandler extends ChannelInboundHandlerAdapter {
private final MessageBroadcaster broadcaster;
private ServerListener serverListener;
public ServerHandler(ServerListener serverListener, MessageBroadcaster broadcaster) {
this.serverListener = serverListener;
this.broadcaster = broadcaster;
}
@Override
public void channelRead(ChannelHandlerContext ctx, Object object)
throws Exception {
Message message = (Message) object;
System.out.println(message);
if (Objects.nonNull(serverListener))
serverListener.newMessage(message);
message.setText(message.getText() + " returned from the server to client");
broadcaster.newMessageToBroadcast(message, ctx.channel());
}
@Override
public void channelActive(ChannelHandlerContext ctx) throws Exception {
broadcaster.addObserver(ctx.channel());
super.channelActive(ctx);
}
@Override
public void channelReadComplete(ChannelHandlerContext ctx) {
ctx.flush();
}
@Override
public void channelInactive(ChannelHandlerContext ctx) throws Exception {
broadcaster.removeObserver(ctx.channel());
super.channelInactive(ctx);
}
}
MessageBroadcaster：
package ch.zhaw.psit3.net.server;
import ch.zhaw.psit3.models.Message;
import io.netty.channel.*;
import java.util.Collections;
import java.util.LinkedHashSet;
import java.util.Set;
public class MessageBroadcaster {
private Set<Channel> channels = Collections.synchronizedSet(new LinkedHashSet<>());
public void addObserver(Channel channel) {
channels.add(channel);
}
public void removeObserver(Channel channel) {
channels.remove(channel);
}
public void newMessageToBroadcast(Message message, Channel originChannel) throws ChannelException {
synchronized (channels) {
for (Channel channel : channels) {
if (!channel.equals(originChannel)) {
if (!channel.isActive()) {
System.out.println("channel not writable");
} else {
ChannelFuture future = channel.writeAndFlush(message);
future.addListener((ChannelFutureListener) future1 -> {
if (!future1.isSuccess()) {
throw new ChannelException("sending of message wasn't successful: ", future1.cause());
}
});
}
}
}
}
}
}
客户：
package ch.zhaw.psit3.net.client;
import ch.zhaw.psit3.models.Enums.ConnectionState;
import ch.zhaw.psit3.models.Enums.OperationType;
import ch.zhaw.psit3.models.NetworkState;
import ch.zhaw.psit3.models.Session;
import ch.zhaw.psit3.models.Message;
import ch.zhaw.psit3.net.common.MessageDecoder;
import ch.zhaw.psit3.net.common.MessageEncoder;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelFuture;
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.NioSocketChannel;
import io.netty.handler.timeout.IdleStateHandler;
import java.util.ArrayList;
import java.util.concurrent.*;
public class Client implements IClient, Runnable {
private ClientListener listener = null;
private NetworkState networkState = new NetworkState();
private final ClientHandler clientHandler = new ClientHandler(listener);
private ExecutorService executor = null;
/*TODO remove after testing core functionality*/
public static void main(String[] args) {
int port = args.length > 0 ? Integer.parseInt(args[0]) : 9090;
Client client = new Client();
client.networkState.activeSession.port = port;
client.startClient();
try {
Thread.sleep(6000);
for (int i = 3; i < 4; i++) {
var msg = new Message();
msg.setText("This is a test text :" + i);
msg.setRange(i);
msg.setTheirOperations(i * 2);
msg.setMyOperations(i * 3);
msg.setMyOperations(i * 4);
msg.setOperationType(OperationType.ADD);
client.sendMessage(msg);
}
} catch (Exception e) {
e.printStackTrace();
}
}
public Client() {
setInitialState();
}
private void setInitialState() {
networkState.state = ConnectionState.NOT_CONNECTED;
networkState.activeSession = new Session();
networkState.sessions = new ArrayList<>();
networkState.activeSession.ip = "127.0.0.1";
networkState.activeSession.port = 9090;
}
private synchronized void startClient() {
if (!(ConnectionState.CONNECTED_TO_SESSION == this.networkState.state)) {
executor = Executors.newFixedThreadPool(1);
executor.execute(this);
this.networkState.state = ConnectionState.CONNECTED_TO_SESSION;
}
}
@Override
public void run() {
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
Bootstrap bootstrap = new Bootstrap();
bootstrap.group(workerGroup);
bootstrap.channel(NioSocketChannel.class);
bootstrap.option(ChannelOption.SO_KEEPALIVE, true);
bootstrap.handler(new ChannelInitializer<SocketChannel>() {
@Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast("idleStateHandler", new IdleStateHandler(30, 30, 0));
ch.pipeline().addLast("messageEncoder", new MessageEncoder());
ch.pipeline().addLast("messageDecoder", new MessageDecoder());
ch.pipeline().addLast("clientHandler", clientHandler);
}
});
ChannelFuture future = bootstrap.connect(networkState.activeSession.ip, networkState.activeSession.port).sync();
future.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
} finally {
workerGroup.shutdownGracefully();
}
}
ClientHandler：
package ch.zhaw.psit3.net.client;
import ch.zhaw.psit3.models.Message;
import ch.zhaw.psit3.net.common.PingMessage;
import io.netty.channel.*;
import io.netty.handler.timeout.IdleState;
import io.netty.handler.timeout.IdleStateEvent;
import java.util.Objects;
public class ClientHandler extends ChannelInboundHandlerAdapter {
private ChannelHandlerContext context;
private ClientListener listener;
public ClientHandler(ClientListener listener) {
this.listener = listener;
}
void addListener(ClientListener listener) {
this.listener = listener;
}
public void sendMessage(Message message) throws Exception {
if (context != null) {
System.out.println(message);
ChannelFuture future = context.writeAndFlush(message);
future.addListener((ChannelFutureListener) future1 -> {
if (!future1.isSuccess()) {
throw new ChannelException("sending of message wasn't successful: ", future1.cause());
}
});
} else {
throw new ChannelException("Channel is not ready yet");
}
}
@Override
public void userEventTriggered(ChannelHandlerContext ctx, Object evt) throws Exception {
if (evt instanceof IdleStateEvent) {
IdleStateEvent e = (IdleStateEvent) evt;
if (e.state() == IdleState.READER_IDLE) {
ctx.writeAndFlush(new PingMessage());
} else if (e.state() == IdleState.WRITER_IDLE) {
ctx.writeAndFlush(new PingMessage());
}
}
}
@Override
public void channelRead(ChannelHandlerContext context, Object object) throws Exception {
Message message = (Message) object;
/* TODO remove sysout */
System.out.println(message);
if (Objects.nonNull(listener))
listener.newMessage(message);
context.close();
}
@Override
public void channelActive(ChannelHandlerContext context) throws Exception {
this.context = context;
}
@Override
public void exceptionCaught(ChannelHandlerContext context, Throwable cause) {
/* todo log and handle exceptions */
cause.printStackTrace();
context.close();
}
@Override
public void channelInactive(ChannelHandlerContext context) throws Exception {
}
}
答案 0 :(得分：1)
我知道了。我在ClientHandler的channelRead（）中具有示例的context.close（），因此一旦接收到消息，便关闭了一个通道。