CODEWITHSUNDEEP
javaproxynetty
user1229043
user1229043

Reputation: 245

Multiple handlers in netty

I would like to make a kind of logging proxy in netty. The goal is to be able to have a web browser make HTTP requests to a netty server, have them be passed on to a back-end web server, but also be able to take certain actions based on HTTP specific things.

There's a couple of useful netty exmaples, HexDumpProxy (which does the proxying part, agnostic to the protocol), and I've taken just a bit of code from HttpSnoopServerHandler.

My code looks like this right now: HexDumpProxyInboundHandler can be found at http://docs.jboss.org/netty/3.2/xref/org/jboss/netty/example/proxy/HexDumpProxyInboundHandler.html

//in HexDumpProxyPipelineFactory
  public ChannelPipeline getPipeline() throws Exception {
      ChannelPipeline p = pipeline(); // Note the static import.
      p.addLast("handler", new HexDumpProxyInboundHandler(cf, remoteHost, remotePort));

      p.addLast("decoder", new HttpRequestDecoder());
      p.addLast("handler2", new HttpSnoopServerHandler());
      return p;
  }


//HttpSnoopServerHandler
public class HttpSnoopServerHandler extends SimpleChannelUpstreamHandler {
  public void messageReceived(ChannelHandlerContext ctx, MessageEvent e) {
    HttpRequest request = (HttpRequest) e.getMessage();
    System.out.println(request.getUri());
    //going to do things based on the URI
  }
}

Unfortunately messageReceived in HttpSnoopServerHandler never gets called - it seems like HexDumpProxyInboundHandler consumes all the events.

How can I have two handlers, where one of them requires a decoder but the other doesn't (I'd rather have HexDumpProxy as it is, where it doesn't need to understand HTTP, it just proxies all connections, but my HttpSnoopHandler needs to have HttpRequestDecoder in front of it)?

Upvotes: 3

Views: 4441

Answers (1)

johnstlr
johnstlr

Reputation: 1431

I've not tried it but you could extend HexDumpProxyInboundHandler and override messageReceived with something like

super.messageReceived(ctx, e);
ctx.sendUpstream(e);

Alternatively you could modify HexDumpProxyInboundHandler directly to that the last thing messageReceived does is call super.messageReceived(ctx,e).

This would only work for inbound data from the client. Data from the service you're proxy-ing would still be passed through without you code seeing it.

Upvotes: 1

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