EXCEPTION: java.nio.channels.NotYetConnectedException for a socket client with netty 3.10.6

Question

i need to connect to a server and i'm following the code below for same:

package SocketServer;
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;
import java.net.InetSocketAddress;
import java.nio.channels.Channel;
import java.util.concurrent.Executor;
import java.util.concurrent.Executors;

import org.jboss.netty.bootstrap.ClientBootstrap;
import org.jboss.netty.channel.ChannelFactory;
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;
import org.jboss.netty.handler.codec.serialization.ObjectEncoder;

public class SocketClient {

    final static Logger logger = Logger.getLogger(SocketClient.class);

public static void write(String bscsString){

    String HOST = PropertyUtils.getProperty("HOST");
    int PORT = Integer.parseInt(System.getProperty("port", PropertyUtils.getProperty("PORT")));

    //create a Boss thread from thread pool
    Executor BossPool = Executors.newCachedThreadPool();
    Executor WorkerPool = Executors.newCachedThreadPool();

    //create NIO client channel factories
    ChannelFactory channelFactory = new NioClientSocketChannelFactory(BossPool,WorkerPool);

    //Client Setup the channel using bootstrap
    ClientBootstrap clientBootstrap = new ClientBootstrap(channelFactory);

    //setup the Channel PipeLine Factory
    ChannelPipelineFactory pipelineFactory = new ChannelPipelineFactory() {
          public ChannelPipeline getPipeline() throws Exception {
            return Channels.pipeline(
              new ObjectEncoder()
            );
          }

        };  

        //set the pipeline
        clientBootstrap.setPipelineFactory(pipelineFactory);

        //connect to host port
    InetSocketAddress addressToConnectTo = new InetSocketAddress(HOST, PORT);

    //connect asynchronously :)
    ChannelFuture cf = clientBootstrap.connect(addressToConnectTo);

        //get the channel to send message
        final org.jboss.netty.channel.Channel channel = cf.getChannel(); //could be a error here
        String s = "hello from client";
        ChannelFuture test = channel.write(s);
        System.out.println("Written on server "+test);
        test.syncUninterruptibly();
        System.out.println("client synced ");   }
}

However, i'm getting the following error:

Nov 23, 2016 8:41:28 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d] OPEN
2016-11-23 20:41:28 INFO  SocketClient:60 - chanelfuture for Written on server org.jboss.netty.channel.DefaultChannelFuture@2f6a9cd7
java.nio.channels.NotYetConnectedException
        at org.jboss.netty.channel.socket.nio.AbstractNioWorker.cleanUpWriteBuffer(AbstractNioWorker.java:431)
        at org.jboss.netty.channel.socket.nio.AbstractNioWorker.writeFromUserCode(AbstractNioWorker.java:128)
        at org.jboss.netty.channel.socket.nio.NioClientSocketPipelineSink.eventSunk(NioClientSocketPipelineSink.java:84)
        at org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendDownstream(DefaultChannelPipeline.java:779)
        at org.jboss.netty.channel.Channels.write(Channels.java:725)
        at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.doEncode(OneToOneEncoder.java:71)
        at org.jboss.netty.handler.codec.oneone.OneToOneEncoder.handleDownstream(OneToOneEncoder.java:59)
        at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:591)
        at org.jboss.netty.channel.DefaultChannelPipeline.sendDownstream(DefaultChannelPipeline.java:582)
        at org.jboss.netty.channel.Channels.write(Channels.java:704)
        at org.jboss.netty.channel.Channels.write(Channels.java:671)
        at org.jboss.netty.channel.AbstractChannel.write(AbstractChannel.java:347)
        at SocketServer.SocketClient.write(SocketClient.java:59)
        at SocketServer.SocketServerHandler.channelReadComplete(SocketServerHandler.java:58)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:408)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:390)
        at io.netty.channel.AbstractChannelHandlerContext.fireChannelReadComplete(AbstractChannelHandlerContext.java:383)
        at io.netty.channel.DefaultChannelPipeline$HeadContext.channelReadComplete(DefaultChannelPipeline.java:1339)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:408)
        at io.netty.channel.AbstractChannelHandlerContext.invokeChannelReadComplete(AbstractChannelHandlerContext.java:390)
        at io.netty.channel.DefaultChannelPipeline.fireChannelReadComplete(DefaultChannelPipeline.java:932)
        at io.netty.channel.nio.AbstractNioByteChannel$NioByteUnsafe.read(AbstractNioByteChannel.java:134)
        at io.netty.channel.nio.NioEventLoop.processSelectedKey(NioEventLoop.java:571)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeysOptimized(NioEventLoop.java:512)
        at io.netty.channel.nio.NioEventLoop.processSelectedKeys(NioEventLoop.java:426)
        at io.netty.channel.nio.NioEventLoop.run(NioEventLoop.java:398)
        at io.netty.util.concurrent.SingleThreadEventExecutor$5.run(SingleThreadEventExecutor.java:877)
        at io.netty.util.concurrent.DefaultThreadFactory$DefaultRunnableDecorator.run(DefaultThreadFactory.java:144)
        at java.lang.Thread.run(Thread.java:745)
Nov 23, 2016 8:41:28 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d] EXCEPTION: java.nio.channels.NotYetConnectedException
Nov 23, 2016 8:41:28 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d, /10.0.41.160:45707 => /10.0.41.160:11011] BOUND: /10.0.41.160:45707
Nov 23, 2016 8:41:28 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d, /10.0.41.160:45707 => /10.0.41.160:11011] CONNECTED: /10.0.41.160:11011
Nov 23, 2016 8:41:48 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d, /10.0.41.160:45707 :> /10.0.41.160:11011] DISCONNECTED
Nov 23, 2016 8:41:48 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d, /10.0.41.160:45707 :> /10.0.41.160:11011] UNBOUND
Nov 23, 2016 8:41:48 PM org.jboss.netty.channel.DefaultChannelPipeline
WARNING: The pipeline contains no upstream handlers; discarding: [id: 0xa0193d7d, /10.0.41.160:45707 :> /10.0.41.160:11011] CLOSED

i've worked with netty a bit only so this one is a bit misleading. it seems it has issues while writing to server, however it throws not yet connected exception

Please guide me in this issue. Thanks

Answer 1

You don't want to call cf.getChannel as that gives you the channel too soon. Instead you should add a listener to the future that will be triggered once the connection has been made.