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MINA has been edited by Nicolas Bouillon (Mar 05, 2009). Change summary: Add samles for filters MINA ComponentThe mina: component is a transport for working with Apache MINA URI formatmina:tcp://hostname[:port] mina:udp://hostname[:port] mina:multicast://hostname[:port] mina:vm://hostname[:port} From Camel 1.3 onwards you can specify a codec in the Registry using the codec option. If you are using TCP and no codec is specified then the textline flag is used to determine if text line based codec or object serialization should be used instead. By default the object serialization is used.
Default behavior changedIn Camel 1.5 the sync option has changed its default value from false to true, as we felt it was confusing for end-users when they used Mina to call remote servers and Camel wouldn't wait for the response. In Camel 1.4 or later codec=textline is no longer supported. Use the textline=true option instead. Using custom codecSee the Mina documentation Sample with sync=falseIn this sample we let Camel expose a service that listen for TCP connections on port 6200. We use the textline codec. In out route we create the mina in the from to create the consumer that listen on port 6200: from("mina:tcp://localhost:6200?textline=true&sync=false").to("mock:result");
As the sample is part of an unit test we test it by sending some data on port 6200 to it. MockEndpoint mock = getMockEndpoint("mock:result"); mock.expectedBodiesReceived("Hello World"); template.sendBody("mina:tcp://localhost:6200?textline=true&sync=false", "Hello World"); assertMockEndpointsSatisfied(); Sample with sync=trueIn the next sample we have a more common use-case where we expose a TCP service on port 6201 also using the textline codec. However this time we want to return a response and indicate that we support this so we set the sync option to true on the consumer. from("mina:tcp://localhost:6201?textline=true&sync=true").process(new Processor() { public void process(Exchange exchange) throws Exception { String body = exchange.getIn().getBody(String.class); exchange.getOut().setBody("Bye " + body); } }); Then we test it by sending some data and retrieving the response using the template.requestBody() method. As we know the response is a String we cast it to String and can assert that the response is in fact something we have dynamically set in our processor code logic. String response = (String)template.requestBody("mina:tcp://localhost:6201?textline=true&sync=true", "World"); assertEquals("Bye World", response); Sample with Spring DSLSpring DSL can of course also be used for Mina. In the simple sample below we expose a TCP server on port 5555: <route> <from uri="mina:tcp://localhost:5555?textline=true"/> <to uri="bean:myTCPOrderHandler"/> </route> In the route above we expose a TCP server on port 5555 using the textline codec and we let a spring bean with the id myTCPOrderHandler handle the request and return a reply. For instance this can be done as: public String handleOrder(String payload) { ... return "Order: OK" } Configuring Mina endpoints using Spring bean styleAvaiable as of Camel 2.0 Configuration of Mina endpoints is now possible using regular Spring bean style configuration in the Spring DSL. However configuring Apache Mina itself is quite complex to setup the acceptor, connector as you can not use simple setters. To resolve this we will leverage the MinaComponent as a Spring factory bean to configure this for us. If you really need to configure this yourself there are setters on the MinaEndpoint to set these when needed. The sample below shows the factory approach: <!-- Creating mina endpoints is a bit complex so we reuse MinaComponnet
as a factory bean to create our endpoint, this is the easiest to do -->
<bean id="myMinaFactory" class="org.apache.camel.component.mina.MinaComponent"/>
<!-- This is our mina endpoint configured with spring, we will use the factory above
to create it for us. The goal is to invoke the createEndpoint method with the
mina configuration parameter we defined using the constructor-arg option -->
<bean id="myMinaEndpoint"
factory-bean="myMinaFactory"
factory-method="createEndpoint">
<constructor-arg index="0" ref="myMinaConfig"/>
</bean>
<!-- this is our mina configuration with plain properties -->
<bean id="myMinaConfig" class="org.apache.camel.component.mina.MinaConfiguration">
<property name="protocol" value="tcp"/>
<property name="host" value="localhost"/>
<property name="port" value="1234"/>
<property name="sync" value="false"/>
</bean>
And then we can refer to our endpoint directly in the route such as: <route> <!-- here we route from or mina endpoint we have defined above --> <from ref="myMinaEndpoint"/> <to uri="mock:result"/> </route> Closing Session When CompleteAvaiable as of Camel 1.6.1 When acting as a server you sometimes want to close the session when e.g. a client conversion is finished. To instruct Camel to close the session you should set add a header with the key CamelMinaCloseSessionWhenComplete to a boolean true value. For instance the example below will close the session after it have written the bye message back to the client: from("mina:tcp://localhost:8080?sync=true&textline=true").process(new Processor() { public void process(Exchange exchange) throws Exception { String body = exchange.getIn().getBody(String.class); exchange.getOut().setBody("Bye " + body); exchange.getOut().setHeader(MinaConsumer.HEADER_CLOSE_SESSION_WHEN_COMPLETE, true); } }); Configuring Mina filtersAvaiable as of Camel 2.0 Filters permits you to use some Mina Filters, such as SslFilter. You can also implement some customized filters. Please note that codec and logger are also Mina IoFitler, and the filters you may define are appended at the end of the FilterChain, then after codec and logger. For instance, the example below will send a keep-alive message after 10 seconds of inactivity: public class KeepAliveFilter extends IoFilterAdapter { @Override public void sessionCreated(NextFilter nextFilter, IoSession session) throws Exception { session.setIdleTime(IdleStatus.BOTH_IDLE, 10); nextFilter.sessionCreated(session); } @Override public void sessionIdle(NextFilter nextFilter, IoSession session, IdleStatus status) throws Exception { session.write("NOOP"); // NOOP is a FTP command for keep alive nextFilter.sessionIdle(session, status); } } As Camel Mina may ues a request-reply scheme, the endpoint as a client would like to drop some message, such as greeting when the connection is established. For example, when you connect to an FTP server, you will get a 220 message with a greeting (220 Welcome to Pure-FTPd). If you don't drop the message, you request-reply scheme will be broken. public class DropGreetingFilter extends IoFilterAdapter { @Override public void messageReceived(NextFilter nextFilter, IoSession session, Object message) throws Exception { if (message instanceof String) { String ftpMessage = (String) message; // "220" is given as greeting. "200 Zzz" is given as a response to "NOOP" (keep alive) if (ftpMessage.startsWith("220") || or ftpMessage.startsWith("200 Zzz")) { // Dropping greeting return; } } nextFilter.messageReceived(session, message); } } Then, you can configure your endpoint. Using Spring DSL: <bean id="myMinaFactory" class="org.apache.camel.component.mina.MinaComponent"/> <bean id="myMinaEndpoint" factory-bean="myMinaFactory" factory-method="createEndpoint"> <constructor-arg index="0" ref="myMinaConfig"/> </bean> <bean id="myMinaConfig" class="org.apache.camel.component.mina.MinaConfiguration"> <property name="protocol" value="tcp" /> <property name="host" value="localhost" /> <property name="port" value="2121" /> <property name="sync" value="true" /> <property name="minaLogger" value="true" /> <property name="filters" ref="listFilters"/> </bean> <bean id="listFilters" class="java.util.ArrayList" > <constructor-arg> <list value-type="org.apache.mina.common.IoFilter"> <bean class="com.example.KeepAliveFilter"/> <bean class="com.example.DropGreetingFilter"/> </list> </constructor-arg> </bean> See Also |
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