netty error: InvalidClassException: failed to read class descriptor - java

What's the correct idiom to send, receive and cast objects between client and server? I'm starting from a simple example, I just want to send specific type between the client and server.
server output:
BUILD SUCCESSFUL
Total time: 3 seconds
Jul 26, 2014 3:36:22 AM io.netty.handler.logging.LoggingHandler channelRegistered
INFO: [id: 0xefbb5b05] REGISTERED
Jul 26, 2014 3:36:22 AM io.netty.handler.logging.LoggingHandler bind
INFO: [id: 0xefbb5b05] BIND(0.0.0.0/0.0.0.0:4454)
Jul 26, 2014 3:36:22 AM io.netty.handler.logging.LoggingHandler channelActive
INFO: [id: 0xefbb5b05, /0:0:0:0:0:0:0:0:4454] ACTIVE
Jul 26, 2014 3:36:32 AM io.netty.handler.logging.LoggingHandler logMessage
INFO: [id: 0xefbb5b05, /0:0:0:0:0:0:0:0:4454] RECEIVED: [id: 0xabdeec06, /127.0.0.1:59934 => /127.0.0.1:4454]
Jul 26, 2014 3:36:32 AM net.bounceme.dur.netty.ServerHandler exceptionCaught
SEVERE: io.netty.handler.codec.DecoderException: java.io.InvalidClassException: failed to read class descriptor
Jul 26, 2014 3:36:32 AM net.bounceme.dur.netty.ServerHandler channelReadComplete
INFO: finished reading..?
^Cthufir#dur:~/NetBeansProjects/AgentServer$
thufir#dur:~/NetBeansProjects/AgentServer$
client output:
BUILD SUCCESSFUL
Total time: 3 seconds
Jul 26, 2014 3:36:32 AM net.bounceme.dur.client.netty.ClientHandler channelActive
INFO:
id 0
phone 0
title null
state undefined
thufir#dur:~/NetBeansProjects/AgentClient$
ServerHandler:
package net.bounceme.dur.netty;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.util.logging.Logger;
import net.bounceme.dur.jdbc.Title;
/**
* Handles both client-side and server-side handler depending on which
* constructor was called.
*/
public class ServerHandler extends ChannelInboundHandlerAdapter {
private static final Logger log = Logger.getLogger(ServerHandler.class.getName());
private RecordsQueueWrapper q = null;
public ServerHandler(RecordsQueueWrapper q) {
this.q = q;
}
#Override
public void channelRead(ChannelHandlerContext ctx, Object obj) {
Title receivedTitle = (Title) obj;
log.info(receivedTitle.toString());
Title nextTitle = q.pop();
ctx.write(nextTitle);
log.info("..channelRead");
}
#Override
public void channelReadComplete(ChannelHandlerContext ctx) {
log.info("finished reading..?");
ctx.flush();
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
log.severe(cause.toString());
ctx.close();
}
}
ClientHandler:
package net.bounceme.dur.client.netty;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundHandlerAdapter;
import java.util.logging.Logger;
import net.bounceme.dur.client.jdbc.Title;
public class ClientHandler extends ChannelInboundHandlerAdapter {
private static final Logger log = Logger.getLogger(ClientHandler.class.getName());
public ClientHandler() {
}
#Override
public void channelActive(ChannelHandlerContext ctx) {
Title firstTitle = new Title();
log.info(firstTitle.toString());
ctx.writeAndFlush(firstTitle);
}
#Override
public void channelRead(ChannelHandlerContext ctx, Object msg) {
try {
Title t = (Title) msg;
log.info(msg.toString());
ctx.write(t);
} catch (ClassCastException cce) { //????
log.warning(cce.toString());
}
}
#Override
public void channelReadComplete(ChannelHandlerContext ctx
) {
ctx.flush();
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause
) {
log.severe(cause.toString());
ctx.close();
}
}
Server:
package net.bounceme.dur.netty;
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
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.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.util.SelfSignedCertificate;
import java.security.cert.CertificateException;
import java.util.logging.Logger;
import javax.net.ssl.SSLException;
import net.bounceme.dur.jdbc.Title;
public final class Server {
private static final Logger log = Logger.getLogger(Server.class.getName());
public static void main(String[] args) throws Exception {
MyProps p = new MyProps();
int port = p.getServerPort();
RecordsQueueWrapper q = new RecordsQueueWrapper();
q.init(99);
new Server().startServer(port, false, q);
}
private void startServer(int port, boolean ssl, final RecordsQueueWrapper q) throws CertificateException, SSLException, InterruptedException {
final SslContext sslCtx;
if (ssl) {
SelfSignedCertificate ssc = new SelfSignedCertificate();
sslCtx = SslContext.newServerContext(ssc.certificate(), ssc.privateKey());
} else {
sslCtx = null;
}
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
if (sslCtx != null) {
p.addLast(sslCtx.newHandler(ch.alloc()));
}
p.addLast(
new ObjectEncoder(),
new ObjectDecoder(ClassResolvers.weakCachingConcurrentResolver(Title.class.getClassLoader())),
//new ObjectDecoder(ClassResolvers.cacheDisabled(null)),
new ServerHandler(q)
);
}
});
b.bind(port).sync().channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
}
Client:
package net.bounceme.dur.client.netty;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
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.codec.serialization.ClassResolvers;
import io.netty.handler.codec.serialization.ObjectDecoder;
import io.netty.handler.codec.serialization.ObjectEncoder;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.util.InsecureTrustManagerFactory;
import java.util.logging.Logger;
import javax.net.ssl.SSLException;
import net.bounceme.dur.client.jdbc.Title;
/**
* Modification of {#link EchoClient} which utilizes Java object serialization.
*/
public final class Client {
private static final Logger log = Logger.getLogger(Client.class.getName());
static final int SIZE = Integer.parseInt(System.getProperty("size", "256"));
public Client() {
}
public void init() throws InterruptedException, SSLException {
MyProps p = new MyProps();
String host = p.getHost();
int port = p.getServerPort();
startClient(host, port, false);
}
private void startClient(final String host, final int port, final boolean SSL) throws SSLException, InterruptedException {
// Configure SSL.
final SslContext sslCtx;
if (SSL) {
sslCtx = SslContext.newClientContext(InsecureTrustManagerFactory.INSTANCE);
} else {
sslCtx = null;
}
EventLoopGroup group = new NioEventLoopGroup();
try {
Bootstrap b = new Bootstrap();
b.group(group)
.channel(NioSocketChannel.class)
.handler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
if (sslCtx != null) {
p.addLast(sslCtx.newHandler(ch.alloc(), host, port));
}
p.addLast(
new ObjectEncoder(),
//new ObjectDecoder(ClassResolvers.cacheDisabled(null)),
new ObjectDecoder(ClassResolvers.weakCachingConcurrentResolver(Title.class.getClassLoader())),
new ClientHandler());
}
});
// Start the connection attempt.
b.connect(host, port).sync().channel().closeFuture().sync();
} finally {
group.shutdownGracefully();
}
}
}
see also:
Strange Netty error whilst deserializing

Please check package of Title object, there are not must be different package name, in server and in client! For example: in server com.server.dto and in client com.server.dto!

Related

How to resolve "org.eclipse.jetty.websocket.api.MessageTooLargeException" for Java WebSocketStompClient

When I'm running a Java WebSocketStompClient, I got below error:
org.eclipse.jetty.websocket.api.MessageTooLargeException: Text message size [73728] exceeds maximum size [65536]
Sample code:
import org.apache.log4j.Logger;
import org.springframework.messaging.simp.stomp.StompFrameHandler;
import org.springframework.messaging.simp.stomp.StompHeaders;
import org.springframework.messaging.simp.stomp.StompSession;
import org.springframework.messaging.simp.stomp.StompSessionHandlerAdapter;
import org.springframework.util.concurrent.ListenableFuture;
import org.springframework.web.socket.WebSocketHttpHeaders;
import org.springframework.web.socket.client.WebSocketClient;
import org.springframework.web.socket.client.standard.StandardWebSocketClient;
import org.springframework.web.socket.messaging.WebSocketStompClient;
import org.springframework.web.socket.sockjs.client.SockJsClient;
import org.springframework.web.socket.sockjs.client.Transport;
import org.springframework.web.socket.sockjs.client.WebSocketTransport;
import org.springframework.web.socket.sockjs.frame.Jackson2SockJsMessageCodec;
import java.lang.reflect.Type;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ExecutionException;
public class HelloClient {
private static Logger logger = Logger.getLogger(HelloClient.class);
StompSession session;
private final static WebSocketHttpHeaders headers = new WebSocketHttpHeaders();
public ListenableFuture<StompSession> connect() {
Transport webSocketTransport = new WebSocketTransport(new StandardWebSocketClient());
List<Transport> transports = Collections.singletonList(webSocketTransport);
SockJsClient sockJsClient = new SockJsClient(transports);
sockJsClient.setMessageCodec(new Jackson2SockJsMessageCodec());
WebSocketStompClient stompClient = new WebSocketStompClient(sockJsClient);
long[] hb = stompClient.getDefaultHeartbeat();
boolean en = stompClient.isDefaultHeartbeatEnabled();
long timeout = stompClient.getReceiptTimeLimit();
String url = "https://www.test.com";
return stompClient.connect(url, headers, new MyHandler());
}
public void subscribeMsg(StompSession stompSession) throws ExecutionException, InterruptedException {
stompSession.subscribe("/topic/test", new StompFrameHandler() {
public Type getPayloadType(StompHeaders stompHeaders) {
return byte[].class;
}
public void handleFrame(StompHeaders stompHeaders, Object o) {
logger.info("Received message " + new String((byte[]) o));
String response = new String((byte[]) o);
}
});
}
private class MyHandler extends StompSessionHandlerAdapter {
public void afterConnected(StompSession stompSession, StompHeaders stompHeaders) {
logger.info("Now connected");
session = stompSession;
}
}
public boolean isConnected() {
try {
Thread.sleep(500);
return session != null && session.isConnected();
} catch (Exception e) {
logger.warn("Error happens when checking connection status, ", e);
return false;
}
}
public static void main(String[] args) throws Exception {
HelloClient helloClient = new HelloClient();
ListenableFuture<StompSession> f = helloClient.connect();
StompSession stompSession = f.get();
helloClient.subscribeMsg(stompSession);
while (true) {
if (!helloClient.isConnected()) {
logger.info("wss diconnected ");
logger.info("need re-create ");
}
}
}
}
How to increase the limitation for a Java stomp websocket client? I found some not related answers How can I set max buffer size for web socket client(Jetty) in Java which are not suitable for stomp websocket client.
Also tried stompClient.setInboundMessageSizeLimit(Integer.MAX_VALUE); which doesn't work.

Netty Pipeline being executed out of order

I am trying to figure out why my pipeline is being executed out of order.
I took the HexDumpProxy example and was trying to turn it into a http-proxy where I can look at all the traffic. For some reason the code is being executed backwards and I can't figure out why.
My server listens on 8443 and takes in the http content. I wanted to read the host header and create a frontend handler to route the data to the server, but my frontend handler executes first despite being last in the pipeline. I am unsure why it is running first I thought it would be execute in the following order.
LoggingHandler
HttpRequestDecoder
HttpObjectAggregator
HttpProxyListener
HttpReEncoder
HTTPProxyFrontEnd
The goal is to remove frontendhandler from the pipeline and have the HTTPProxy listener add it to the pipeline after reading the host header. but if I remove the frontend handler no data is transferred. Using breakpoints HTTPProxyFrontEnd is hit before HttpProxyListener. I am unsure why it is being executed so out of order.
Main
```
EventLoopGroup bossGroup = new NioEventLoopGroup(1);
EventLoopGroup workerGroup = new NioEventLoopGroup();
try {
ServerBootstrap b = new ServerBootstrap();
b.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.handler(new LoggingHandler(LogLevel.INFO))
.childHandler(new HttpProxyServerInitializer(REMOTE_HOST, REMOTE_PORT))
.childOption(ChannelOption.AUTO_READ, false)
.bind(LOCAL_PORT).sync().channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
```
Pipeline
```
import io.netty.buffer.ByteBuf;
import io.netty.channel.Channel;
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.ChannelPipeline;
import io.netty.handler.codec.MessageToByteEncoder;
import io.netty.handler.codec.http.*;
import io.netty.handler.logging.LogLevel;
import io.netty.handler.logging.LoggingHandler;
import io.netty.handler.ssl.SslContext;
import io.netty.handler.ssl.SslContextBuilder;
import io.netty.handler.ssl.SslHandler;
import io.netty.handler.ssl.util.SelfSignedCertificate;
import javax.net.ssl.SSLEngine;
public class HttpProxyServerInitializer extends ChannelInitializer {
private final String remoteHost;
private final int remotePort;
public HttpProxyServerInitializer(String remoteHost, int remotePort) {
this.remoteHost = remoteHost;
this.remotePort = remotePort;
}
#Override
protected void initChannel(Channel ch) throws Exception {
ch.pipeline().addLast(
new LoggingHandler(LogLevel.INFO),
new HttpRequestDecoder(),
new HttpObjectAggregator(8192),
new HttpProxyListener(),
new HttpReEncoder(),
new HTTPProxyFrontEnd(remoteHost, remotePort));
}
}
```
Proxy Front end
```
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.embedded.EmbeddedChannel;
import io.netty.handler.codec.DecoderResult;
import io.netty.handler.codec.http.*;
import io.netty.handler.codec.http.cookie.ServerCookieDecoder;
import io.netty.handler.codec.http.cookie.ServerCookieEncoder;
import io.netty.util.CharsetUtil;
import java.net.SocketAddress;
import java.util.List;
import java.util.Map;
import java.util.Set;
import static io.netty.handler.codec.http.HttpResponseStatus.BAD_REQUEST;
import static io.netty.handler.codec.http.HttpResponseStatus.OK;
import static io.netty.handler.codec.http.HttpVersion.HTTP_1_1;
public class HTTPProxyFrontEnd extends ChannelInboundHandlerAdapter {
private final String remoteHost;
private final int remotePort;
private final StringBuilder buf = new StringBuilder();
private HttpRequest request;
// As we use inboundChannel.eventLoop() when building the Bootstrap this does not need to be volatile as
// the outboundChannel will use the same EventLoop (and therefore Thread) as the inboundChannel.
private Channel outboundChannel;
public HTTPProxyFrontEnd(String remoteHost, int remotePort) {
this.remoteHost = remoteHost;
this.remotePort = remotePort;
}
#Override
public void channelActive(ChannelHandlerContext ctx) {
System.out.println("HTTPFrontEnd");
final Channel inboundChannel = ctx.channel();
// Start the connection attempt.
Bootstrap b = new Bootstrap();
b.group(inboundChannel.eventLoop())
.channel(ctx.channel().getClass())
.handler(new HexDumpProxyBackendHandler(inboundChannel))
.option(ChannelOption.AUTO_READ, false);
ChannelFuture f = b.connect(remoteHost, remotePort);
SocketAddress test = ctx.channel().remoteAddress();
outboundChannel = f.channel();
f.addListener(new ChannelFutureListener() {
#Override
public void operationComplete(ChannelFuture future) {
if (future.isSuccess()) {
// connection complete start to read first data
inboundChannel.read();
} else {
// Close the connection if the connection attempt has failed.
inboundChannel.close();
}
}
});
}
#Override
public void channelRead(final ChannelHandlerContext ctx, Object msg) throws InterruptedException {
if (outboundChannel.isActive()) {
outboundChannel.writeAndFlush(msg).addListener(new ChannelFutureListener() {
#Override
public void operationComplete(ChannelFuture future) {
if (future.isSuccess()) {
// was able to flush out data, start to read the next chunk
ctx.channel().read();
} else {
future.channel().close();
}
}
});
}
}
private boolean writeResponse(HttpObject currentObj, ChannelHandlerContext ctx) {
// Decide whether to close the connection or not.
boolean keepAlive = HttpUtil.isKeepAlive(request);
// Build the response object.
FullHttpResponse response = new DefaultFullHttpResponse(
HTTP_1_1, currentObj.decoderResult().isSuccess()? OK : BAD_REQUEST,
Unpooled.copiedBuffer(buf.toString(), CharsetUtil.UTF_8));
response.headers().set(HttpHeaderNames.CONTENT_TYPE, "text/plain; charset=UTF-8");
if (keepAlive) {
// Add 'Content-Length' header only for a keep-alive connection.
response.headers().setInt(HttpHeaderNames.CONTENT_LENGTH, response.content().readableBytes());
// Add keep alive header as per:
// - http://www.w3.org/Protocols/HTTP/1.1/draft-ietf-http-v11-spec-01.html#Connection
response.headers().set(HttpHeaderNames.CONNECTION, HttpHeaderValues.KEEP_ALIVE);
}
// Encode the cookie.
String cookieString = request.headers().get(HttpHeaderNames.COOKIE);
if (cookieString != null) {
Set<io.netty.handler.codec.http.cookie.Cookie> cookies = ServerCookieDecoder.STRICT.decode(cookieString);
if (!cookies.isEmpty()) {
// Reset the cookies if necessary.
for (io.netty.handler.codec.http.cookie.Cookie cookie: cookies) {
response.headers().add(HttpHeaderNames.SET_COOKIE, io.netty.handler.codec.http.cookie.ServerCookieEncoder.STRICT.encode(cookie));
}
}
} else {
// Browser sent no cookie. Add some.
response.headers().add(HttpHeaderNames.SET_COOKIE, io.netty.handler.codec.http.cookie.ServerCookieEncoder.STRICT.encode("key1", "value1"));
response.headers().add(HttpHeaderNames.SET_COOKIE, ServerCookieEncoder.STRICT.encode("key2", "value2"));
}
// Write the response.
//ctx.writeAndFlush(response);
return keepAlive;
}
private static void appendDecoderResult(StringBuilder buf, HttpObject o) {
DecoderResult result = o.decoderResult();
if (result.isSuccess()) {
return;
}
buf.append(".. WITH DECODER FAILURE: ");
buf.append(result.cause());
buf.append("\r\n");
}
#Override
public void channelInactive(ChannelHandlerContext ctx) {
if (outboundChannel != null) {
closeOnFlush(outboundChannel);
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) {
cause.printStackTrace();
closeOnFlush(ctx.channel());
}
/**
* Closes the specified channel after all queued write requests are flushed.
*/
static void closeOnFlush(Channel ch) {
if (ch.isActive()) {
ch.writeAndFlush(Unpooled.EMPTY_BUFFER).addListener(ChannelFutureListener.CLOSE);
}
}
}
```

how to create large number of connects with netty 5.0

I want to create large number client connection to the server for the test purpose. I accomplish this by creating thread per connection, so I can only create 3000 connection on my machine. below is my code:
package com.stepnetwork.iot.apsclient.application;
import io.netty.bootstrap.Bootstrap;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.Unpooled;
import io.netty.channel.*;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioSocketChannel;
/**
* Created by sam on 3/22/16.
*/
public class DtuClient extends Thread {
private static final String HOST = "192.168.54.36";
private static final int PORT = 30080;
private EventLoopGroup workerGroup;
private String dtuCode;
public DtuClient(String dtuCode, EventLoopGroup workerGroup) {
this.dtuCode = dtuCode;
this.workerGroup = workerGroup;
}
public void run() {
Bootstrap bootstrap = new Bootstrap(); // (1)
try {
bootstrap.group(workerGroup); // (2)
bootstrap.channel(NioSocketChannel.class); // (3)
bootstrap.option(ChannelOption.SO_KEEPALIVE, true); // (4)
bootstrap.handler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new MyClientHandler());
}
});
ChannelFuture feature = bootstrap.connect(HOST, PORT).sync();
feature.addListener((future) -> {
System.out.println(dtuCode + " connected to server");
Channel channel = feature.channel();
ByteBuf buffer = Unpooled.buffer(256);
buffer.writeBytes(dtuCode.getBytes());
channel.writeAndFlush(buffer);
});
feature.channel().closeFuture().sync();
} catch (InterruptedException e) {
e.printStackTrace();
}
System.out.println("completed");
}
}
Can I get more connection.
I had try another solution after doing google research, but the channel will close automatically.
here is my another solution
package com.stepnetwork.iot.apsclient.application;
import io.netty.bootstrap.Bootstrap;
import io.netty.channel.Channel;
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 java.util.ArrayList;
import java.util.List;
/**
* Created by sam on 3/22/16.
*/
public class Test {
private static final String HOST = "192.168.54.36";
private static final int PORT = 30080;
public static void main(String[] args) throws InterruptedException {
EventLoopGroup workerGroup = new NioEventLoopGroup();
Bootstrap bootstrap = new Bootstrap(); // (1)
try {
bootstrap.group(workerGroup); // (2)
bootstrap.channel(NioSocketChannel.class); // (3)
bootstrap.option(ChannelOption.SO_KEEPALIVE, true); // (4)
bootstrap.handler(new ChannelInitializer<SocketChannel>() {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(new MyClientHandler());
}
});
List<Channel> channels = new ArrayList<>();
// create many connection here, but the channel will be closed atomically
for (int i = 0; i < 10000; i++) {
channels.add(bootstrap.connect(HOST, PORT).sync().channel());
}
} catch (InterruptedException e) {
e.printStackTrace();
}
while (true) {
Thread.sleep(Integer.MAX_VALUE);
}
}
}

Migrating sendUpstream in Netty 4

I'm migrating from netty 3 to netty 4. I have a pipeline handler that acts as a classic filter, intercepting/handling noncompliant messages on the way, and shoveling compliant ones upstream.
Based on the documentation (http://netty.io/wiki/new-and-noteworthy.html), I expected to use ctx.fireInboundBufferUpdated() in lieu of ctx.sendUpStream() to relay inbound. However, I've found this doesn't work, but ChannelHandlerUtil.addToNextInboundBuffer() does. I'd love some guidance as to:
My confusion over the current docs assertion that ctx.sendUpstream -> ctx.fireInboundBufferUpdated and,
What is the best practice in this case, if different than what I've done below.
The code:
//The pipeline
public class ServerInitializer extends ChannelInitializer<SocketChannel> {
#Override
public void initChannel(SocketChannel ch) throws Exception {
ChannelPipeline p = ch.pipeline();
p.addLast("decoder", new HttpRequestDecoder());
p.addLast("encoder", new HttpResponseEncoder());
p.addLast("inbound", InboundHttpRequestFilter.INSTANCE);
p.addLast("handler", handlerClass.newInstance());
}
}
//The filter
public class InboundHttpRequestFilter extends
ChannelInboundMessageHandlerAdapter<Object> {
#Override
public void messageReceived(ChannelHandlerContext ctx, Object msg)
throws Exception {
... discard/handle as necessary …;
//ctx.fireInboundBufferUpdated(); - doesn't propagate upstream
ChannelHandlerUtil.addToNextInboundBuffer(ctx, msg); // sends upstream
}
}
Try this :
ctx.nextInboundMessageBuffer().add(msg)
Javadoc :
Interface ChannelHandlerContext
MessageBuf<Object> nextInboundMessageBuffer()
Return the MessageBuf of the next ChannelInboundMessageHandler in the pipeline.
Netty 4 Multiple Handler Example :
MultiHandlerServer.java
import io.netty.bootstrap.ServerBootstrap;
import io.netty.channel.ChannelFuture;
import io.netty.channel.ChannelInitializer;
import io.netty.channel.nio.NioEventLoopGroup;
import io.netty.channel.socket.SocketChannel;
import io.netty.channel.socket.nio.NioServerSocketChannel;
import io.netty.handler.codec.LineBasedFrameDecoder;
import io.netty.handler.codec.string.StringDecoder;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import java.nio.charset.Charset;
public class MultiHandlerServer {
private static final Logger logger = LoggerFactory.getLogger(MultiHandlerServer.class);
final int port;
public MultiHandlerServer(final int port) {
this.port = port;
}
public void run() throws InterruptedException {
final NioEventLoopGroup bossGroup = new NioEventLoopGroup();
final NioEventLoopGroup workerGroup = new NioEventLoopGroup();
try {
final ServerBootstrap serverBootstrap = new ServerBootstrap()
.group(bossGroup, workerGroup)
.channel(NioServerSocketChannel.class)
.childHandler(new ChannelInitializer<SocketChannel>() {
#Override
protected void initChannel(SocketChannel ch) throws Exception {
ch.pipeline().addLast(
new LineBasedFrameDecoder(8192),
new StringDecoder(Charset.forName("UTF-8")),
new MultiHandler01(), new MultiHandler02());
}
});
final ChannelFuture future = serverBootstrap.bind(port).sync();
future.channel().closeFuture().sync();
} finally {
bossGroup.shutdownGracefully();
workerGroup.shutdownGracefully();
}
}
public static void main(String[] args) throws InterruptedException {
final MultiHandlerServer client = new MultiHandlerServer(8080);
client.run();
}
}
MultiHandler01.java
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandlerAdapter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*/
class MultiHandler01 extends ChannelInboundMessageHandlerAdapter<String> {
private Logger logger = LoggerFactory.getLogger(MultiHandler01.class);
MultiHandler01() {
}
#Override
public void messageReceived(ChannelHandlerContext ctx, String msg) throws Exception {
logger.info(String.format("Handler01 receive message: %s", msg));
ctx.nextInboundMessageBuffer().add(msg);
ctx.fireInboundBufferUpdated();
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.error("Exception caught: %s", ctx.channel().remoteAddress(), cause);
ctx.close();
}
}
MultiHandler02.java
import io.netty.channel.ChannelHandlerContext;
import io.netty.channel.ChannelInboundMessageHandlerAdapter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
/**
*/
class MultiHandler02 extends ChannelInboundMessageHandlerAdapter<String> {
private Logger logger = LoggerFactory.getLogger(MultiHandler02.class);
MultiHandler02() {
}
#Override
public void messageReceived(ChannelHandlerContext ctx, String msg) throws Exception {
logger.info(String.format("Handler02 receive message: %s", msg));
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, Throwable cause) throws Exception {
logger.error("Exception caught: %s", ctx.channel().remoteAddress(), cause);
ctx.close();
}
}

The netty server seems to be blocked when I add a ExecutionHandler?

THE SCENE:
I am writing a echo client and server. The data being transfered is a string:
Client encode a string,and send it to server.
Server recv data, decode string, then encode the received string, send it back to client.
The above process will be repeated 100000 times.(Note: the connection is persistent).
DEFERENT CONTIONS:
When I run ONE server and TWO client at the same time, everything is ok,every client receives 100000 messages and terminated normally.
But When I add a ExecutionHandler on server, and then run ONE server and TWO client at the same time, one client will never terminate, and the network traffic is zero.
I cant locate the key point of this problem for now, will you give me some suggestions?
MY CODE:
string encoder , string decoder, client handler , server handler , client main ,server main.
//Decoder=======================================================
import java.nio.charset.Charset;
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.frame.FrameDecoder;
public class Dcd extends FrameDecoder {
public static final Charset cs = Charset.forName("utf8");
#Override
protected Object decode(ChannelHandlerContext ctx, Channel channel,
ChannelBuffer buffer) throws Exception {
if (buffer.readableBytes() < 4) {
return null;
}
int headlen = 4;
int length = buffer.getInt(0);
if (buffer.readableBytes() < length + headlen) {
return null;
}
String ret = buffer.toString(headlen, length, cs);
buffer.skipBytes(length + headlen);
return ret;
}
}
//Encoder =======================================================
import org.jboss.netty.buffer.ChannelBuffer;
import org.jboss.netty.buffer.ChannelBuffers;
import org.jboss.netty.channel.Channel;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.handler.codec.oneone.OneToOneEncoder;
public class Ecd extends OneToOneEncoder {
#Override
protected Object encode(ChannelHandlerContext ctx, Channel channel,
Object msg) throws Exception {
if (!(msg instanceof String)) {
return msg;
}
byte[] data = ((String) msg).getBytes();
ChannelBuffer buf = ChannelBuffers.dynamicBuffer(data.length + 4, ctx
.getChannel().getConfig().getBufferFactory());
buf.writeInt(data.length);
buf.writeBytes(data);
return buf;
}
}
//Client handler =======================================================
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.ChannelStateEvent;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
/**
* Handler implementation for the echo client. It initiates the ping-pong
* traffic between the echo client and server by sending the first message to
* the server.
*/
public class EchoClientHandler extends SimpleChannelUpstreamHandler {
private static final Logger logger = Logger
.getLogger(EchoClientHandler.class.getName());
private final AtomicLong transferredBytes = new AtomicLong();
private final AtomicInteger counter = new AtomicInteger(0);
private final AtomicLong startTime = new AtomicLong(0);
private String dd;
/**
* Creates a client-side handler.
*/
public EchoClientHandler(String data) {
dd = data;
}
public long getTransferredBytes() {
return transferredBytes.get();
}
#Override
public void channelConnected(ChannelHandlerContext ctx, ChannelStateEvent e) {
// Send the first message. Server will not send anything here
// because the firstMessage's capacity is 0.
startTime.set(System.currentTimeMillis());
Channels.write(ctx.getChannel(), dd);
}
#Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
// Send back the received message to the remote peer.
transferredBytes.addAndGet(((String) e.getMessage()).length());
int i = counter.incrementAndGet();
int N = 100000;
if (i < N) {
e.getChannel().write(e.getMessage());
} else {
ctx.getChannel().close();
System.out.println(N * 1.0
/ (System.currentTimeMillis() - startTime.get()) * 1000);
}
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
// Close the connection when an exception is raised.
logger.log(Level.WARNING, "Unexpected exception from downstream.",
e.getCause());
e.getChannel().close();
}
}
//Client main =======================================================
import java.net.InetSocketAddress;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.channel.ChannelFuture;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.socket.nio.NioClientSocketChannelFactory;
/**
* Sends one message when a connection is open and echoes back any received data
* to the server. Simply put, the echo client initiates the ping-pong traffic
* between the echo client and server by sending the first message to the
* server.
*/
public class EchoClient {
private final String host;
private final int port;
public EchoClient(String host, int port) {
this.host = host;
this.port = port;
}
public void run() {
// Configure the client.
final ClientBootstrap bootstrap = new ClientBootstrap(
new NioClientSocketChannelFactory(
Executors.newCachedThreadPool(),
Executors.newCachedThreadPool()));
// Set up the pipeline factory.
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
public ChannelPipeline getPipeline() throws Exception {
return Channels.pipeline(new Dcd(), new Ecd(),
new EchoClientHandler("abcdd"));
}
});
bootstrap.setOption("sendBufferSize", 1048576);
bootstrap.setOption("receiveBufferSize", 1048576);
bootstrap.setOption("tcpNoDelay", true);
bootstrap.setOption("writeBufferLowWaterMark", 32 * 1024);
bootstrap.setOption("writeBufferHighWaterMark", 64 * 1024);
List<ChannelFuture> list = new ArrayList<ChannelFuture>();
for (int i = 0; i < 1; i++) {
// Start the connection attempt.
ChannelFuture future = bootstrap.connect(new InetSocketAddress(
host, port));
// Wait until the connection is closed or the connection
// attempt
// fails.
list.add(future);
}
for (ChannelFuture f : list) {
f.getChannel().getCloseFuture().awaitUninterruptibly();
}
// Shut down thread pools to exit.
bootstrap.releaseExternalResources();
}
private static void testOne() {
final String host = "192.168.0.102";
final int port = 8000;
new EchoClient(host, port).run();
}
public static void main(String[] args) throws Exception {
testOne();
}
}
//server handler =======================================================
import java.util.concurrent.atomic.AtomicLong;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.jboss.netty.channel.ChannelHandlerContext;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.ExceptionEvent;
import org.jboss.netty.channel.MessageEvent;
import org.jboss.netty.channel.SimpleChannelUpstreamHandler;
/**
* Handler implementation for the echo server.
*/
public class EchoServerHandler extends SimpleChannelUpstreamHandler {
private static final Logger logger = Logger
.getLogger(EchoServerHandler.class.getName());
private final AtomicLong transferredBytes = new AtomicLong();
public long getTransferredBytes() {
return transferredBytes.get();
}
#Override
public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
// Send back the received message to the remote peer.
transferredBytes.addAndGet(((String) e.getMessage()).length());
Channels.write(ctx.getChannel(), e.getMessage());
}
#Override
public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {
// Close the connection when an exception is raised.
logger.log(Level.WARNING, "Unexpected exception from downstream.",
e.getCause());
e.getChannel().close();
}
}
//Server main =======================================================
import java.net.InetSocketAddress;
import java.util.concurrent.Executors;
import org.jboss.netty.bootstrap.ServerBootstrap;
import org.jboss.netty.channel.ChannelPipeline;
import org.jboss.netty.channel.ChannelPipelineFactory;
import org.jboss.netty.channel.Channels;
import org.jboss.netty.channel.socket.nio.NioServerSocketChannelFactory;
import org.jboss.netty.handler.execution.ExecutionHandler;
import org.jboss.netty.handler.execution.OrderedMemoryAwareThreadPoolExecutor;
/**
* Echoes back any received data from a client.
*/
public class EchoServer {
private final int port;
public EchoServer(int port) {
this.port = port;
}
public void run() {
// Configure the server.
ServerBootstrap bootstrap = new ServerBootstrap(
new NioServerSocketChannelFactory(
Executors.newCachedThreadPool(),
Executors.newCachedThreadPool()));
System.out.println(Runtime.getRuntime().availableProcessors() * 2);
final ExecutionHandler executionHandler = new ExecutionHandler(
new OrderedMemoryAwareThreadPoolExecutor(16, 1048576, 1048576));
// Set up the pipeline factory.
bootstrap.setPipelineFactory(new ChannelPipelineFactory() {
public ChannelPipeline getPipeline() throws Exception {
System.out.println("new pipe");
return Channels.pipeline(new Dcd(), new Ecd(),
executionHandler, new EchoServerHandler());
}
});
bootstrap.setOption("child.sendBufferSize", 1048576);
bootstrap.setOption("child.receiveBufferSize", 1048576);
bootstrap.setOption("child.tcpNoDelay", true);
bootstrap.setOption("child.writeBufferLowWaterMark", 32 * 1024);
bootstrap.setOption("child.writeBufferHighWaterMark", 64 * 1024);
// Bind and start to accept incoming connections.
bootstrap.bind(new InetSocketAddress(port));
}
public static void main(String[] args) throws Exception {
int port = 8000;
new EchoServer(port).run();
}
}
I have found the reason now, it is a hard work, but full with pleasure.
When added a ExecutionHandler, the message will be wrapped into a Runnable task, and will be executed in a ChildExecutor. The key point is here : A task maybe added to ChildExecutor when the executor almostly exit , then is will be ignored by the ChildExecutor.
I added three lines code and some comments, the final code looks like below, and it works now,should I mail to the author? :
private final class ChildExecutor implements Executor, Runnable {
private final Queue<Runnable> tasks = QueueFactory
.createQueue(Runnable.class);
private final AtomicBoolean isRunning = new AtomicBoolean();
public void execute(Runnable command) {
// TODO: What todo if the add return false ?
tasks.add(command);
if (!isRunning.get()) {
doUnorderedExecute(this);
} else {
}
}
public void run() {
// check if its already running by using CAS. If so just return
// here. So in the worst case the thread
// is executed and do nothing
boolean acquired = false;
if (isRunning.compareAndSet(false, true)) {
acquired = true;
try {
Thread thread = Thread.currentThread();
for (;;) {
final Runnable task = tasks.poll();
// if the task is null we should exit the loop
if (task == null) {
break;
}
boolean ran = false;
beforeExecute(thread, task);
try {
task.run();
ran = true;
onAfterExecute(task, null);
} catch (RuntimeException e) {
if (!ran) {
onAfterExecute(task, e);
}
throw e;
}
}
//TODO NOTE (I added): between here and "isRunning.set(false)",some new tasks maybe added.
} finally {
// set it back to not running
isRunning.set(false);
}
}
//TODO NOTE (I added): Do the remaining works.
if (acquired && !isRunning.get() && tasks.peek() != null) {
doUnorderedExecute(this);
}
}
}
This was a bug and will be fixed in 3.4.0.Alpha2.
See https://github.com/netty/netty/issues/234

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