How to handle exception in decoders/handlers?

[infectedrhythms]

Ok so now the exception is the last handler.

But how do I write to the socket as

	@Override
	public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e) {

		e.getCause().printStackTrace();

		e.getChannel().write("Test");

		
		//ChannelFuture cf = ch.write("Test");
		
		//cf.addListener(ChannelFutureListener.CLOSE);
		//ch.close();
	}

throws...


java.lang.ClassCastException: java.lang.String cannot be cast to
org.jboss.netty.buffer.ChannelBuffer
	at
org.jboss.netty.channel.socket.nio.NioWorker.writeUnfair(NioWorker.java:438)
	at org.jboss.netty.channel.socket.nio.NioWorker.write(NioWorker.java:411)
	at
org.jboss.netty.channel.socket.nio.NioServerSocketPipelineSink.handleAcceptedSocket(NioServerSocketPipelineSink.java:138)
	at
org.jboss.netty.channel.socket.nio.NioServerSocketPipelineSink.eventSunk(NioServerSocketPipelineSink.java:78)
	at org.jboss.netty.channel.Channels.write(Channels.java:626)
	at org.jboss.netty.channel.Channels.write(Channels.java:592)
	at org.jboss.netty.channel.AbstractChannel.write(AbstractChannel.java:203)
	at
com.rbs.threedsecure.mpi.services.broker.ThreeDHandler.exceptionCaught(ThreeDHandler.java:51)
	at
com.rbs.threedsecure.mpi.services.broker.ThreeDHandler.handleUpstream(ThreeDHandler.java:32)
	at
org.jboss.netty.handler.codec.frame.FrameDecoder.exceptionCaught(FrameDecoder.java:194)
	at org.jboss.netty.channel.Channels.fireExceptionCaught(Channels.java:440)
	at
org.jboss.netty.channel.AbstractChannelSink.exceptionCaught(AbstractChannelSink.java:59)
	at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:293)
	at org.jboss.netty.channel.Channels.fireMessageReceived(Channels.java:280)
	at
org.jboss.netty.channel.socket.nio.NioWorker.readIntoHeapBuffer(NioWorker.java:300)
	at
org.jboss.netty.channel.socket.nio.NioWorker.processSelectedKeys(NioWorker.java:254)
	at org.jboss.netty.channel.socket.nio.NioWorker.run(NioWorker.java:163)
	at
java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:886)
	at
java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:908)
	at java.lang.Thread.run(Thread.java:619)



Trustin Lee wrote:
> 
> Hi,
> 
> It seems like one of the handlers in your pipeline closes the connection
> on an exceptionCaught event (perhaps the last handler.)  I would catch
> the exception in the last handler and send the error message there
> rather than sending it in the decoder, because it's often a good idea to
> separate protocol state from codec.
> 
> HTH,
> Trustin
> 
> On 2009-06-20 오전 2:42, infectedrhythms wrote:
>> 
>> Hi, I have implemented a simple decoder and it works fine.
>> 
>> Now if there is an error I want to throw an exception catch and reply
>> back
>> to the client, kind of like an HTTP 500 error.
>> 
>> So if the decoder fails it should write back to the client the error that
>> occurred.
>> 
>> 	@Override
>> 	protected Object decode(ChannelHandlerContext ctx, Channel channel,
>> ChannelBuffer buf) throws Exception {
>> 
>> 		... do stuff here...
>> 
>> 		throw new Exception("Errrorrrr!");
>> 	}
>> 
>> 	@Override
>> 	public void exceptionCaught(ChannelHandlerContext ctx, ExceptionEvent e)
>> 			throws Exception {
>> 		
>> 		super.exceptionCaught(ctx, e);
>> 		
>> 		e.getChannel().write("Damn it Jim!"); <-- Throws a
>> ClosedChannelException
>> 				
>> 	}
> 
> 
> -- 
> — Trustin Lee, http://gleamynode.net/
> 
> 
>  
> _______________________________________________
> netty-users mailing list
> netty-users at lists.jboss.org
> https://lists.jboss.org/mailman/listinfo/netty-users
> 
> 

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