Netty

Netty Component

Available as of Camel 2.3

The netty component in Camel is a socket communication component, based on the
JBoss Netty community offering (available under an Apache 2.0 license). Netty is a
NIO client server framework which enables quick and easy development of network applications
such as protocol servers and clients. Netty greatly simplifies and streamlines network
programming such as TCP and UDP socket server.

This camel component supports both producer and consumer endpoints.

The netty component has several options and allows fine-grained control of a number of
TCP/UDP communication parameters (buffer sizes, keepAlives, tcpNoDelay etc) and facilitates
both In-Only and In-Out communication on a Camel route.

Maven users will need to add the following dependency to their pom.xml for this component:

<dependency>
    <groupId>org.apache.camel</groupId>
    <artifactId>camel-netty</artifactId>
    <version>x.x.x</version>
    <!-- use the same version as your Camel core version -->
</dependency>

URI format

The URI scheme for a netty component is as follows

netty:tcp://localhost:99999[?options]
netty:udp://remotehost:99999/[?options]

This component supports producer and consumer endpoints for both TCP and UDP.

You can append query options to the URI in the following format, ?option=value&option=value&...

Options

Registry based Options

Codec Handlers and SSL Keystores can be enlisted in the Registry, such as in the Spring XML file.
The values that could be passed in, are the following:

Sending Messages to/from a Netty endpoint

Netty Producer

In Producer mode, the component provides the ability to send payloads to a socket endpoint
using either TCP or UDP protocols (with optional SSL support).

The producer mode supports both one-way and request-response based operations.

Netty Consumer

In Consumer mode, the component provides the ability to:

• listen on a specified socket using either TCP or UDP protocols (with optional SSL support),
• receive requests on the socket using text/xml, binary and serialized object based payloads and
• send them along on a route as message exchanges.

The consumer mode supports both one-way and request-response based operations.

Usage Samples

A UDP Netty endpoint using Request-Reply and serialized object payload

RouteBuilder builder = new RouteBuilder() {
  public void configure() {
    from("netty:udp://localhost:5155?sync=true")
      .process(new Processor() {
         public void process(Exchange exchange) throws Exception {
           Poetry poetry = (Poetry) exchange.getIn().getBody();
           poetry.setPoet("Dr. Sarojini Naidu");
           exchange.getOut().setBody(poetry);
         }
       }
    }
};

A TCP based Netty consumer endpoint using One-way communication

RouteBuilder builder = new RouteBuilder() {
  public void configure() {
       from("netty:tcp://localhost:5150")
           .to("mock:result"); 
  }
};

An SSL/TCP based Netty consumer endpoint using Request-Reply communication

JndiRegistry registry = new JndiRegistry(createJndiContext());
registry.bind("password", "changeit");
registry.bind("ksf", new File("src/test/resources/keystore.jks"));
registry.bind("tsf", new File("src/test/resources/keystore.jks"));

context.createRegistry(registry);
context.addRoutes(new RouteBuilder() {
  public void configure() {
      String netty_ssl_endpoint = 
         "netty:tcp://localhost:5150sync=true&ssl=true&passphrase=#password"
         + "&keyStoreFile=#ksf&trustStoreFile=#tsf";
      String return_string =
         "When You Go Home, Tell Them Of Us And Say,"
         + "For Your Tomorrow, We Gave Our Today.";
      
      from(netty_ssl_endpoint)
       .process(new Processor() {
          public void process(Exchange exchange) throws Exception {
            exchange.getOut().setBody(return_string);                           
          }
       }
  }
});

Using Multiple Codecs

In certain cases it may be necessary to add chains of encoders and decoders to the netty pipeline. To add multpile codecs to a camel netty endpoint the 'encoders' and 'decoders' uri parameters should be used. Like the 'encoder' and 'decoder' parameters they are used to supply references (to lists of ChannelUpstreamHandlers and ChannelDownstreamHandlers) that should be added to the pipeline. Note that if encoders is specified then the encoder param will be ignored, similarly for decoders and the decoder param.

The lists of codecs need to be added to the Camel's registry so they can be resolved when the endpoint is created.

Spring's native collections support can be used to specify the codec lists in an application context

The bean names can then be used in netty endpoint definitions either as a comma separated list or contained in a List e.g.

or via spring.

See Also

• Configuring Camel
• Component
• Endpoint
• Getting Started

• MINA