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h2. 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|http://netty.io/] project.
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 nettyNetty 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:
{code:xml}
<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>
{code}

h3. URI format

The URI scheme for a netty component is as follows

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

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&...}}

h3. Options
{div:class=confluenceTableSmall}
|| Name || Default Value || Description ||
| {{keepAlive}} | {{true}} | Setting to ensure socket is not closed due to inactivity |
| {{tcpNoDelay}} | {{true}} | Setting to improve TCP protocol performance |
| {{broadcast}} | {{false}} | Setting to choose Multicast over UDP |
| {{connectTimeout}} | {{10000}} | Time to wait for a socket connection to be available. Value is in millis. |
| {{reuseAddress}} | {{true}} | Setting to facilitate socket multiplexing |
| {{sync}} | {{true}} | Setting to set endpoint as one-way or request-response |
| {{ssl}} | {{false}} | Setting to specify whether SSL encryption is applied to this endpoint |
| {{sendBufferSize}} | {{65536 bytes}} | The TCP/UDP buffer sizes to be used during outbound communication. Size is bytes. |
| {{receiveBufferSize}} | {{65536 bytes}} | The TCP/UDP buffer sizes to be used during inbound communication. Size is bytes. |
| {{corePoolSize}} | {{10}} | The number of allocated threads at component startup. Defaults to 10. *Note:* This option is removed from Camel 2.9.2 onwards. As we rely on Nettys default settings. |
| {{maxPoolSize}} | {{100}} | The maximum number of threads that may be allocated to this endpoint. Defaults to 100. *Note:* This option is removed from Camel 2.9.2 onwards. As we rely on Nettys default settings. |
| {{disconnect}} | {{false}} | Whether or not to disconnect(close) from Netty Channel right after use. Can be used for both consumer and producer. |
| {{lazyChannelCreation}} | {{true}} | Channels can be lazily created to avoid exceptions, if the remote server is not up and running when the Camel producer is started. |
| {{transferExchange}} | {{false}} | Only used for TCP. You can transfer the exchange over the wire instead of just the body. The following fields are transferred: In body, Out body, fault body, In headers, Out headers, fault headers, exchange properties, exchange exception. This requires that the objects are serializable. Camel will exclude any non-serializable objects and log it at WARN level. |
| {{disconnectOnNoReply}} | {{true}} | If sync is enabled then this option dictates NettyConsumer if it should disconnect where there is no reply to send back. |
| {{noReplyLogLevel}} | {{WARN}} | If sync is enabled this option dictates NettyConsumer which logging level to use when logging a there is no reply to send back. Values are: {{FATAL, ERROR, INFO, DEBUG, OFF}}. |
| {{allowDefaultCodec}} | {{true}} | *Camel 2.4:* The netty component installs a default codec if both, encoder/deocder is null and textline is false. Setting allowDefaultCodec to false prevents the netty component from installing a default codec as the first element in the filter chain. |
| {{textline}} | {{false}} | *Camel 2.4:* Only used for TCP. If no codec is specified, you can use this flag to indicate a text line based codec; if not specified or the value is false, then Object Serialization is assumed over TCP. |
| {{delimiter}} | {{LINE}} | *Camel 2.4:* The delimiter to use for the textline codec. Possible values are {{LINE}} and {{NULL}}. |
| {{decoderMaxLineLength}} | {{1024}} | *Camel 2.4:* The max line length to use for the textline codec. |
| {{autoAppendDelimiter}} | {{true}} | *Camel 2.4:* Whether or not to auto append missing end delimiter when sending using the textline codec. |
| {{encoding}} | {{null}} | *Camel 2.4:* The encoding (a charset name) to use for the textline codec. If not provided, Camel will use the JVM default Charset. |
| {{workerCount}} | {{null}} | *Camel 2.9:* When netty works on nio mode, it uses default workerCount parameter from Netty, which is cpu_core_threads*2. User can use this operation to override the default workerCount from Netty |
| {{sslContextParametersRef}} | null | *Camel 2.9:* Reference to a {{org.apache.camel.util.jsse.SSLContextParameters}} in the [CAMEL:Registry].&nbsp; This reference overrides any configured SSLContextParameters at the component level.&nbsp; See [Using the JSSE Configuration Utility|#Using the JSSE Configuration Utility]. |
| {{receiveBufferSizePredictor}} | null | *Camel 2.9:* Configures the buffer size predictor. See details at Jetty documentation and this [mail thread|http://lists.jboss.org/pipermail/netty-users/2010-January/001958.html]. |

{div}

h3. 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:

{div:class=confluenceTableSmall}
|| Name || Description ||
| {{passphrase}} | password setting to use in order to encrypt/decrypt payloads sent using SSH |
| {{keyStoreFormat}} | keystore format to be used for payload encryption. Defaults to "JKS" if not set |
| {{securityProvider}} | Security provider to be used for payload encryption. Defaults to "SunX509" if not set. |
| {{keyStoreFile}} | Client side certificate keystore to be used for encryption |
| {{trustStoreFile}} | Server side certificate keystore to be used for encryption |
| {{sslHandler}} | Reference to a class that could be used to return an SSL Handler |
| {{encoder}} | A custom Handler class that can be used to perform special marshalling of outbound payloads. Must override {{org.jboss.netty.channel.ChannelDownStreamHandler}}. |
| {{encorders}} | A list of encoder to be used. You can use a String which have values separated by comma, and have the values be looked up in the [Registry]. Just remember to prefix the value with # so Camel knows it should lookup. |
| {{decoder}} | A custom Handler class that can be used to perform special marshalling of inbound payloads. Must override {{org.jboss.netty.channel.ChannelUpStreamHandler}}. |
| {{decoders}} | A list of decorder to be used. You can use a String which have values separated by comma, and have the values be looked up in the [Registry]. Just remember to prefix the value with # so Camel knows it should lookup. |
{div}

h3. Sending Messages to/from a Netty endpoint

h4. 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.

h4. 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.

h3. Usage Samples

h4. A UDP Netty endpoint using Request-Reply and serialized object payload
{code}
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);
         }
       }
    }
};
{code}

h4. A TCP based Netty consumer endpoint using One-way communication
{code}
RouteBuilder builder = new RouteBuilder() {
  public void configure() {
       from("netty:tcp://localhost:5150")
           .to("mock:result");
  }
};
{code}

h4. An SSL/TCP based Netty consumer endpoint using Request-Reply communication

h5. Using the JSSE Configuration Utility

As of Camel 2.9, the Netty component supports SSL/TLS configuration through the [Camel JSSE Configuration Utility|CAMEL:Camel Configuration Utilities].&nbsp;  This utility greatly decreases the amount of component specific code  you need to write and is configurable at the endpoint and component  levels.&nbsp; The following examples demonstrate how to use the utility with  the Netty component.

h6. Programmatic configuration of the component
{code}
KeyStoreParameters ksp = new KeyStoreParameters();
ksp.setResource("/users/home/server/keystore.jks");
ksp.setPassword("keystorePassword");

KeyManagersParameters kmp = new KeyManagersParameters();
kmp.setKeyStore(ksp);
kmp.setKeyPassword("keyPassword");

SSLContextParameters scp = new SSLContextParameters();
scp.setKeyManagers(kmp);

NettyComponent nettyComponent = getContext().getComponent("netty", NettyComponent.class);
nettyComponent.setSslContextParameters(scp);
{code}

h6. Spring DSL based configuration of endpoint
{code:xml}
...
  <camel:sslContextParameters
      id="sslContextParameters">
    <camel:keyManagers
        keyPassword="keyPassword">
      <camel:keyStore
          resource="/users/home/server/keystore.jks"
          password="keystorePassword"/>
    </camel:keyManagers>
  </camel:sslContextParameters>...
...
  <to uri="netty:tcp://localhost:5150?sync=true&ssl=true&sslContextParameters=#sslContextParameters"/>
...
{code}

h5. Using Basic SSL/TLS configuration on the Jetty Component

{code}
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:5150?sync=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);
          }
       }
  }
});
{code}

h4. 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.

{snippet:id=registry-beans|lang=java|url=camel/trunk/components/camel-netty/src/test/java/org/apache/camel/component/netty/MultipleCodecsTest.java}

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

{snippet:id=registry-beans|lang=xml|url=camel/trunk/components/camel-netty/src/test/resources/org/apache/camel/component/netty/multiple-codecs.xml}

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

{snippet:id=routes|lang=java|url=camel/trunk/components/camel-netty/src/test/java/org/apache/camel/component/netty/MultipleCodecsTest.java}

or via spring.

{snippet:id=routes|lang=xml|url=camel/trunk/components/camel-netty/src/test/resources/org/apache/camel/component/netty/multiple-codecs.xml}

h3. Closing Channel When Complete

When acting as a server you sometimes want to close the channel when, for example, a client conversion is finished.
You can do this by simply setting the endpoint option {{disconnect=true}}.

However you can also instruct Camel on a per message basis as follows.
To instruct Camel to close the channel, you should add a header with the key {{CamelNettyCloseChannelWhenComplete}} set to a boolean {{true}} value.
For instance, the example below will close the channel after it has written the bye message back to the client:
{code}
        from("netty:tcp://localhost:8080").process(new Processor() {
            public void process(Exchange exchange) throws Exception {
                String body = exchange.getIn().getBody(String.class);
                exchange.getOut().setBody("Bye " + body);
                // some condition which determines if we should close
                if (close) {
                    exchange.getOut().setHeader(NettyConstants.NETTY_CLOSE_CHANNEL_WHEN_COMPLETE, true);
                }
            }
        });
{code}

h3. Adding custom channel pipeline factories to gain complete control over a created pipeline

*Available as of Camel 2.5*

Custom channel pipelines provide complete control to the user over the handler/interceptor chain by inserting custom handler(s), encoder(s) & decoders without having to specify them in the Netty Endpoint URL in a very simple way.

In order to add a custom pipeline, a custom channel pipeline factory must be created and registered with the context via the context registry (JNDIRegistry,or the camel-spring ApplicationContextRegistry etc).

A custom pipeline factory must be constructed as follows
* A Producer linked channel pipeline factory must extend the abstract class {{ClientPipelineFactory}}.
* A Consumer linked channel pipeline factory must extend the abstract class {{ServerPipelineFactory}}.
* *Camel 2.9.1 or older:* The classes can optionallyshould override the getPipeline() method in order to insert custom handler(s), encoder(s) and decoder(s). Not overriding the getPipeline() method creates a pipeline with no handlers, encoders or decoders wired to the pipeline.

The* example below shows how *Camel 2.9.2 or newer:* The classes must implement the getPipeline(NettyProducer) / getPipeline(NettyConsumer) method in order to insert custom handler(s), encoder(s) and decoder(s). 

The example below shows how ServerChannel Pipeline factory may be created
{code:title=Camel 2.9.1 or older}
public class SampleServerChannelPipelineFactory extends ServerPipelineFactory {
    private int maxLineSize = 1024;

    private boolean invoked;

    public ChannelPipeline getPipeline() throws Exception {
        invoked = true;

public ChannelPipeline getPipeline() throws Exception {
        ChannelPipeline channelPipeline = Channels.pipeline();

        channelPipeline.addLast("encoder-SD", new StringEncoder(CharsetUtil.UTF_8));
        channelPipeline.addLast("decoder-DELIM", new DelimiterBasedFrameDecoder(maxLineSize, true, Delimiters.lineDelimiter()));
        channelPipeline.addLast("decoder-SD", new StringDecoder(CharsetUtil.UTF_8));
        // here we add the default Camel ServerChannelHandler for the consumer, to allow Camel to route the message etc.
        channelPipeline.addLast("handler", new ServerChannelHandler(consumer));

        return channelPipeline;
    }
}
{code}

And from Camel 2.9.2 onwards you do
{code:title=Camel 2.9.2 or newer}
public class SampleServerChannelPipelineFactory extends ServerPipelineFactory {
    private int maxLineSize = 1024;

    public ChannelPipeline getPipeline(NettyConsumer consumer) throws Exception {
        ChannelPipeline channelPipeline = Channels.pipeline();

        channelPipeline.addLast("encoder-SD", new StringEncoder(CharsetUtil.UTF_8));
        channelPipeline.addLast("decoder-DELIM", new DelimiterBasedFrameDecoder(maxLineSize, true, Delimiters.lineDelimiter()));
        channelPipeline.addLast("decoder-SD", new StringDecoder(CharsetUtil.UTF_8));
        channelPipeline.addLast("handler", new ServerChannelHandler(consumer));

        return channelPipeline;// here we add the default Camel ServerChannelHandler for the consumer, to allow Camel to route the message etc.
    }

    public boolean isfactoryInvoked() {channelPipeline.addLast("handler", new ServerChannelHandler(consumer));

        return invokedchannelPipeline;
    }
}
{code}

The custom channel pipeline factory can then be added to the registry and instantiated/utilized on a camel route in the following way
{code}
Registry registry = camelContext.getRegistry();
serverPipelineFactory = new TestServerChannelPipelineFactory();
registry.bind("spf", serverPipelineFactory);
context.addRoutes(new RouteBuilder() {
  public void configure() {
      String netty_ssl_endpoint =
         "netty:tcp://localhost:5150?serverPipelineFactory=#spf"
      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);
          }
       }
  }
});

{code}


{include:Endpoint See Also}
- [Mina]