Chapter 214. Mina2 Component
Available as of Camel version 2.10
The mina2: component is a transport for working with Apache MINA 2.x
Favor using Netty as Netty is a much more active maintained and popular project than Apache Mina currently is
INFO: Be careful with sync=false on consumer endpoints. Since camel-mina2 all consumer exchanges are InOut. This is different to camel-mina.
Maven users will need to add the following dependency to their pom.xml for this component:
<dependency>
<groupId>org.apache.camel</groupId>
<artifactId>camel-mina2</artifactId>
<version>x.x.x</version>
<!-- use the same version as your Camel core version -->
</dependency>214.1. URI format
mina2:tcp://hostname[:port][?options] mina2:udp://hostname[:port][?options] mina2:vm://hostname[:port][?options]
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 if no codec is specified the default uses a basic ByteBuffer based codec.
The VM protocol is used as a direct forwarding mechanism in the same JVM.
A Mina producer has a default timeout value of 30 seconds, while it waits for a response from the remote server.
In normal use, camel-mina only supports marshalling the body content—message headers and exchange properties are not sent.
However, the option, transferExchange, does allow you to transfer the exchange itself over the wire. See options below.
You can append query options to the URI in the following format, ?option=value&option=value&…
214.2. Options
The Mina2 component supports 3 options which are listed below.
| Name | Description | Default | Type |
|---|---|---|---|
| configuration (advanced) | To use the shared mina configuration. | Mina2Configuration | |
| useGlobalSslContext Parameters (security) | Enable usage of global SSL context parameters. | false | boolean |
| resolveProperty Placeholders (advanced) | Whether the component should resolve property placeholders on itself when starting. Only properties which are of String type can use property placeholders. | true | boolean |
The Mina2 endpoint is configured using URI syntax:
mina2:protocol:host:port
with the following path and query parameters:
214.2.1. Path Parameters (3 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| protocol | Required Protocol to use | String | |
| host | Required Hostname to use. Use localhost or 0.0.0.0 for local server as consumer. For producer use the hostname or ip address of the remote server. | String | |
| port | Required Port number | int |
214.2.2. Query Parameters (27 parameters):
| Name | Description | Default | Type |
|---|---|---|---|
| disconnect (common) | Whether or not to disconnect(close) from Mina session right after use. Can be used for both consumer and producer. | false | boolean |
| minaLogger (common) | You can enable the Apache MINA logging filter. Apache MINA uses slf4j logging at INFO level to log all input and output. | false | boolean |
| sync (common) | Setting to set endpoint as one-way or request-response. | true | boolean |
| timeout (common) | You can configure the timeout that specifies how long to wait for a response from a remote server. The timeout unit is in milliseconds, so 60000 is 60 seconds. | 30000 | long |
| writeTimeout (common) | Maximum amount of time it should take to send data to the MINA session. Default is 10000 milliseconds. | 10000 | long |
| bridgeErrorHandler (consumer) | Allows for bridging the consumer to the Camel routing Error Handler, which mean any exceptions occurred while the consumer is trying to pickup incoming messages, or the likes, will now be processed as a message and handled by the routing Error Handler. By default the consumer will use the org.apache.camel.spi.ExceptionHandler to deal with exceptions, that will be logged at WARN or ERROR level and ignored. | false | boolean |
| clientMode (consumer) | If the clientMode is true, mina consumer will connect the address as a TCP client. | false | boolean |
| disconnectOnNoReply (consumer) | If sync is enabled then this option dictates MinaConsumer if it should disconnect where there is no reply to send back. | true | boolean |
| exceptionHandler (consumer) | To let the consumer use a custom ExceptionHandler. Notice if the option bridgeErrorHandler is enabled then this options is not in use. By default the consumer will deal with exceptions, that will be logged at WARN or ERROR level and ignored. | ExceptionHandler | |
| exchangePattern (consumer) | Sets the exchange pattern when the consumer creates an exchange. | ExchangePattern | |
| noReplyLogLevel (consumer) | If sync is enabled this option dictates MinaConsumer which logging level to use when logging a there is no reply to send back. | WARN | LoggingLevel |
| cachedAddress (producer) | Whether to create the InetAddress once and reuse. Setting this to false allows to pickup DNS changes in the network. | true | boolean |
| lazySessionCreation (producer) | Sessions can be lazily created to avoid exceptions, if the remote server is not up and running when the Camel producer is started. | true | boolean |
| maximumPoolSize (advanced) | Number of worker threads in the worker pool for TCP and UDP | 16 | int |
| orderedThreadPoolExecutor (advanced) | Whether to use ordered thread pool, to ensure events are processed orderly on the same channel. | true | boolean |
| synchronous (advanced) | Sets whether synchronous processing should be strictly used, or Camel is allowed to use asynchronous processing (if supported). | false | boolean |
| transferExchange (advanced) | 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. | false | boolean |
| allowDefaultCodec (codec) | The mina component installs a default codec if both, codec is null and textline is false. Setting allowDefaultCodec to false prevents the mina component from installing a default codec as the first element in the filter chain. This is useful in scenarios where another filter must be the first in the filter chain, like the SSL filter. | true | boolean |
| codec (codec) | To use a custom minda codec implementation. | ProtocolCodecFactory | |
| decoderMaxLineLength (codec) | To set the textline protocol decoder max line length. By default the default value of Mina itself is used which are 1024. | 1024 | int |
| encoderMaxLineLength (codec) | To set the textline protocol encoder max line length. By default the default value of Mina itself is used which are Integer.MAX_VALUE. | -1 | int |
| encoding (codec) | You can configure the encoding (a charset name) to use for the TCP textline codec and the UDP protocol. If not provided, Camel will use the JVM default Charset | String | |
| filters (codec) | You can set a list of Mina IoFilters to use. | List | |
| textline (codec) | 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. | false | boolean |
| textlineDelimiter (codec) | Only used for TCP and if textline=true. Sets the text line delimiter to use. If none provided, Camel will use DEFAULT. This delimiter is used to mark the end of text. | Mina2TextLineDelimiter | |
| autoStartTls (security) | Whether to auto start SSL handshake. | true | boolean |
| sslContextParameters (security) | To configure SSL security. | SSLContextParameters |
214.3. Using a custom codec
See the Mina how to write your own codec. To use your custom codec with camel-mina, you should register your codec in the Registry; for example, by creating a bean in the Spring XML file. Then use the codec option to specify the bean ID of your codec. See HL7 that has a custom codec.
214.4. Sample with sync=false
In this sample, Camel exposes a service that listens for TCP connections on port 6200. We use the textline codec. In our route, we create a Mina consumer endpoint that listens on port 6200:
from("mina2:tcp://localhost:" + port1 + "?textline=true&sync=false").to("mock:result");As the sample is part of a unit test, we test it by sending some data to it on port 6200.
MockEndpoint mock = getMockEndpoint("mock:result");
mock.expectedBodiesReceived("Hello World");
template.sendBody("mina2:tcp://localhost:" + port1 + "?textline=true&sync=false", "Hello World");
assertMockEndpointsSatisfied();214.5. 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 use the textline codec. However, this time we want to return a response, so we set the sync option to true on the consumer.
from("mina2:tcp://localhost:" + port2 + "?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 the sample 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("mina2:tcp://localhost:" + port2 + "?textline=true&sync=true", "World");
assertEquals("Bye World", response);214.6. Sample with Spring DSL
Spring DSL can, of course, also be used for MINA. In the sample below we expose a TCP server on port 5555:
<route>
<from uri="mina2: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. We let the Spring bean with ID, myTCPOrderHandler, handle the request and return a reply. For instance, the handler bean could be implemented as follows:
public String handleOrder(String payload) {
...
return "Order: OK"
}214.7. Closing Session When Complete
When acting as a server you sometimes want to close the session when, for example, a client conversion is finished. To instruct Camel to close the session, you should add a header with the key CamelMinaCloseSessionWhenComplete set to a boolean true value.
For instance, the example below will close the session after it has written the bye message back to the client:
from("mina2: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(Mina2Constants.MINA_CLOSE_SESSION_WHEN_COMPLETE, true);
}
});214.8. Get the IoSession for message
You can get the IoSession from the message header with this key Mina2Constants.MINA_IOSESSION, and also get the local host address with the key Mina2Constants.MINA_LOCAL_ADDRESS and remote host address with the key Mina2Constants.MINA_REMOTE_ADDRESS.
214.9. Configuring Mina filters
Filters permit you to use some Mina Filters, such as SslFilter. You can also implement some customized filters. Please note that codec and logger are also implemented as Mina filters of type, IoFilter. Any filters you may define are appended to the end of the filter chain; that is, after codec and logger.
214.10. See Also
- Configuring Camel
- Component
- Endpoint
- Getting Started
- Netty
