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Netty ComponentAvailable as of Camel 2.14 The netty4 component in Camel is a socket communication component, based on the Netty project version 4. 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 <dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-netty4</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>
URI formatThe URI scheme for a netty component is as follows netty4:tcp://localhost:99999[?options] netty4: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, Options
Registry based OptionsCodec Handlers and SSL Keystores can be enlisted in the Registry, such as in the Spring XML file.
Important: Read below about using non shareable encoders/decoders. Using non shareable encoders or decodersIf your encoders or decoders is not shareable (eg they have the @Shareable class annotation), then your encoder/decoder must implement the The Netty component offers a Sending Messages to/from a Netty endpointNetty ProducerIn Producer mode, the component provides the ability to send payloads to a socket endpoint The producer mode supports both one-way and request-response based operations. Netty ConsumerIn Consumer mode, the component provides the ability to:
The consumer mode supports both one-way and request-response based operations. Usage SamplesA UDP Netty endpoint using Request-Reply and serialized object payloadRouteBuilder builder = new RouteBuilder() {
public void configure() {
from("netty4: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 communicationRouteBuilder builder = new RouteBuilder() {
public void configure() {
from("netty4:tcp://localhost:5150")
.to("mock:result");
}
};
An SSL/TCP based Netty consumer endpoint using Request-Reply communicationUsing the JSSE Configuration UtilityAs of Camel 2.9, the Netty component supports SSL/TLS configuration through the Camel JSSE Configuration Utility. This utility greatly decreases the amount of component specific code you need to write and is configurable at the endpoint and component levels. The following examples demonstrate how to use the utility with the Netty component. Programmatic configuration of the componentKeyStoreParameters 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("netty4", NettyComponent.class);
nettyComponent.setSslContextParameters(scp);
Spring DSL based configuration of endpoint...
<camel:sslContextParameters
id="sslContextParameters">
<camel:keyManagers
keyPassword="keyPassword">
<camel:keyStore
resource="/users/home/server/keystore.jks"
password="keystorePassword"/>
</camel:keyManagers>
</camel:sslContextParameters>...
...
<to uri="netty4:tcp://localhost:5150?sync=true&ssl=true&sslContextParameters=#sslContextParameters"/>
...
Using Basic SSL/TLS configuration on the Jetty ComponentJndiRegistry 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 =
"netty4: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);
}
}
}
});
Getting access to SSLSession and the client certificateAvailable as of Camel 2.12 You can get access to the SSLSession session = exchange.getIn().getHeader(NettyConstants.NETTY_SSL_SESSION, SSLSession.class); // get the first certificate which is client certificate javax.security.cert.X509Certificate cert = session.getPeerCertificateChain()[0]; Principal principal = cert.getSubjectDN(); Remember to set The option Using Multiple CodecsIn 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. Read further above about using non shareable encoders/decoders. The lists of codecs need to be added to the Camel's registry so they can be resolved when the endpoint is created. ChannelHandlerFactory lengthDecoder = ChannelHandlerFactories.newLengthFieldBasedFrameDecoder(1048576, 0, 4, 0, 4);
StringDecoder stringDecoder = new StringDecoder();
registry.bind("length-decoder", lengthDecoder);
registry.bind("string-decoder", stringDecoder);
LengthFieldPrepender lengthEncoder = new LengthFieldPrepender(4);
StringEncoder stringEncoder = new StringEncoder();
registry.bind("length-encoder", lengthEncoder);
registry.bind("string-encoder", stringEncoder);
List<ChannelHandler> decoders = new ArrayList<ChannelHandler>();
decoders.add(lengthDecoder);
decoders.add(stringDecoder);
List<ChannelHandler> encoders = new ArrayList<ChannelHandler>();
encoders.add(lengthEncoder);
encoders.add(stringEncoder);
registry.bind("encoders", encoders);
registry.bind("decoders", decoders);
Spring's native collections support can be used to specify the codec lists in an application context
<util:list id="decoders" list-class="java.util.LinkedList">
<bean class="org.apache.camel.component.netty4.ChannelHandlerFactories" factory-method="newLengthFieldBasedFrameDecoder">
<constructor-arg value="1048576"/>
<constructor-arg value="0"/>
<constructor-arg value="4"/>
<constructor-arg value="0"/>
<constructor-arg value="4"/>
</bean>
<bean class="io.netty.handler.codec.string.StringDecoder"/>
</util:list>
<util:list id="encoders" list-class="java.util.LinkedList">
<bean class="io.netty.handler.codec.LengthFieldPrepender">
<constructor-arg value="4"/>
</bean>
<bean class="io.netty.handler.codec.string.StringEncoder"/>
</util:list>
<bean id="length-encoder" class="io.netty.handler.codec.LengthFieldPrepender">
<constructor-arg value="4"/>
</bean>
<bean id="string-encoder" class="io.netty.handler.codec.string.StringEncoder"/>
<bean id="length-decoder" class="org.apache.camel.component.netty4.ChannelHandlerFactories" factory-method="newLengthFieldBasedFrameDecoder">
<constructor-arg value="1048576"/>
<constructor-arg value="0"/>
<constructor-arg value="4"/>
<constructor-arg value="0"/>
<constructor-arg value="4"/>
</bean>
<bean id="string-decoder" class="io.netty.handler.codec.string.StringDecoder"/>
The bean names can then be used in netty endpoint definitions either as a comma separated list or contained in a List e.g. from("direct:multiple-codec").to("netty4:tcp://localhost:{{port}}?encoders=#encoders&sync=false");
from("netty4:tcp://localhost:{{port}}?decoders=#length-decoder,#string-decoder&sync=false").to("mock:multiple-codec");
or via spring. <camelContext id="multiple-netty-codecs-context" xmlns="http://camel.apache.org/schema/spring">
<route>
<from uri="direct:multiple-codec"/>
<to uri="netty4:tcp://localhost:5150?encoders=#encoders&sync=false"/>
</route>
<route>
<from uri="netty4:tcp://localhost:5150?decoders=#length-decoder,#string-decoder&sync=false"/>
<to uri="mock:multiple-codec"/>
</route>
</camelContext>
Closing Channel When CompleteWhen acting as a server you sometimes want to close the channel when, for example, a client conversion is finished. However you can also instruct Camel on a per message basis as follows. from("netty4: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);
}
}
});
Adding custom channel pipeline factories to gain complete control over a created pipelineCustom 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
The example below shows how ServerInitializerFactory factory may be created Using custom pipeline factory public class SampleServerInitializerFactory extends ServerInitializerFactory {
private int maxLineSize = 1024;
protected void initChannel(Channel ch) throws Exception {
ChannelPipeline channelPipeline = ch.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));
}
}
The custom channel pipeline factory can then be added to the registry and instantiated/utilized on a camel route in the following way Registry registry = camelContext.getRegistry();
ServerInitializerFactory factory = new TestServerInitializerFactory();
registry.bind("spf", factory);
context.addRoutes(new RouteBuilder() {
public void configure() {
String netty_ssl_endpoint =
"netty4:tcp://localhost:5150?serverInitializerFactory=#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);
}
}
}
});
Reusing Netty boss and worker thread poolsAvailable as of Camel 2.12 Netty has two kind of thread pools: boss and worker. By default each Netty consumer and producer has their private thread pools. If you want to reuse these thread pools among multiple consumers or producers then the thread pools must be created and enlisted in the Registry. For example using Spring XML we can create a shared worker thread pool using the <!-- use the worker pool builder to create to help create the shared thread pool -->
<bean id="poolBuilder" class="org.apache.camel.component.netty.NettyWorkerPoolBuilder">
<property name="workerCount" value="2"/>
</bean>
<!-- the shared worker thread pool -->
<bean id="sharedPool" class="org.jboss.netty.channel.socket.nio.WorkerPool"
factory-bean="poolBuilder" factory-method="build" destroy-method="shutdown">
</bean>
For boss thread pool there is a Then in the Camel routes we can refer to this worker pools by configuring the <route>
<from uri="netty4:tcp://localhost:5021?textline=true&sync=true&workerPool=#sharedPool&usingExecutorService=false"/>
<to uri="log:result"/>
...
</route>
And if we have another route we can refer to the shared worker pool: <route>
<from uri="netty4:tcp://localhost:5022?textline=true&sync=true&workerPool=#sharedPool&usingExecutorService=false"/>
<to uri="log:result"/>
...
</route>
... and so forth. |
