MINA Component
The mina: component is a transport for working with Apache MINA
URI format
mina: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.
For UDP/Multicast if no codec is specified the default uses a basic ByteBuffer based codec.
Multicast also has a shorthand notation mcast.
The VM protocol is used as a direct forwarding mechanism in the same JVM. See the MINA VM-Pipe API documentation for details.
A MinaProducer has a default timeout value of 30 seconds, while it waits for a response from the remote server.
In normal usage camel-mina only supports marshalling the body content - message headers and exchange properties will not be sent.
However the option transferExchange does allow to transfer the exchange itself over the wire. See options below.
Options
Option |
Default Value |
Description |
|---|---|---|
codec |
null |
As of 1.3 or later you can refer to a named ProtocolCodecFactory instance in your Registry such as your Spring ApplicationContext which is then used for the marshalling |
textline |
false |
Only used for TCP. If no codec is specified then you can use this flag in 1.3 or later to indicate a text line based codec; if not specified or the value is false then Object Serialization is assumed over TCP. |
textlineDelimiter |
DEFAULT |
Camel 1.5.1/2.0 Only used for TCP and if textline=true. Sets the text line delimiter to use. Possible values are: |
sync |
false/true |
As of 1.3 or later you can configure the exchange pattern to be either InOnly (default) or InOut. Setting sync=true means a synchronous exchange (InOut), where the client can read the response from MINA (The exchange out message). The default value has changed in Camel 1.5 to true. In older releases the default value is false. |
lazySessionCreation |
false |
As of 1.3 or later session can be lazy created to avoid exceptions if the remote server is not up and running when the Camel producer is started. |
timeout |
30000 |
As of 1.3 or later you can configure the timeout while waiting for a response from a remote server. The timeout unit is in millis, so 60000 is 60 seconds. The timeout is only used for MinaProducer. |
encoding |
JVM Default |
As of 1.3 or later you can configure the encoding (is a charset name) to use for the TCP textline codec and the UDP protocol. If not provided Camel will use the JVM default Charset. |
transferExchange |
false |
Only used for TCP. As of 1.3 or later you can transfer the exchange over the wire instead of just the body. The following fields is 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. |
minaLogger |
false |
As of 1.3 or later you can enable Apache MINA logging filter. Apache MINA uses slf4j logging at INFO level to log all input and output. |
Default behavior changed
In 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 codec
See the Mina documentation how to write your own codec. To use your custom codec with camel-mina you should register your codec in the Registry such as the Spring XML file. Then use the codec option to set your codec with its bean id. See HL7 that has a custom codec.
Sample with sync=false
In 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:
As the sample is part of an unit test we test it by sending some data on port 6200 to it.
Sample with sync=true
In 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.
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.
Sample with Spring DSL
Spring 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 style
Avaiable 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:
And then we can refer to our endpoint directly in the route such as: