The mina: component is a transport for working with Apache MINA
![]() | Deprecated |
---|---|
The MINA component is deprecated, because the Apache Mina 1.x project is end-of-life. Use Netty instead. |
mina:tcp://hostname[:port][?options] mina:udp://hostname[:port][?options] mina: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. See the MINA VM-Pipe API documentation for details.
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—essage 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&...
Option | Default Value | Description |
---|---|---|
codec
|
null
|
You can refer to a named
ProtocolCodecFactory instance in your
Registry such as your
Spring ApplicationContext , which is then
used for the marshalling. |
codec
|
null
|
Apache Camel 2.0: You must use
the # notation to look up your codec in
the Registry. For example,
use #myCodec to look up a bean with the
id value, myCodec .
|
disconnect
|
false
|
Camel 2.3: Whether or not to disconnect(close) from Mina session right after use. Can be used for both consumer and producer. |
textline
|
false
|
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. |
textlineDelimiter
|
DEFAULT
|
Only used for TCP and if textline=true. Sets the text line delimiter
to use. Possible values are: DEFAULT ,
AUTO , WINDOWS ,
UNIX or MAC . If
none provided, Apache Camel will use DEFAULT .
This delimiter is used to mark the end of text. |
sync
|
true
|
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 Apache Camel 1.5 to
true . In older releases, the default
value is false . |
lazySessionCreation
|
See description | Sessions can be lazily created to avoid exceptions, if the
remote server is not up and running when the Apache Camel
producer is started. From Apache Camel 2.0 onwards, the default
is true . In Apache Camel 1.x, the default is
false . |
timeout
|
30000
|
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. The timeout is only used for Mina producer. |
encoding
|
JVM Default | You can configure the encoding (a charset name) to use for the TCP textline codec and the UDP protocol. If not provided, Apache Camel will use the JVM default Charset. |
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. Apache Camel will exclude
any non-serializable objects and log it at
WARN level. |
minaLogger
|
false
|
You can enable the Apache MINA logging filter. Apache MINA
uses slf4j logging at
INFO level to log all input and
output. |
filters
|
null
|
As of 2.0, you can set a list of Mina
IoFilters to register. The
|
encoderMaxLineLength
|
-1
|
As of 2.1, you can set the textline protocol encoder max
line length. By default the default value of Mina itself is
used which are Integer.MAX_VALUE . |
decoderMaxLineLength
|
-1
|
As of 2.1, you can set the textline protocol decoder max line length. By default the default value of Mina itself is used which are 1024. |
allowDefaultCodec
|
true
|
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. |
disconnectOnNoReply
|
true
|
Camel 2.3: If sync is enabled then this option dictates MinaConsumer if it should disconnect where there is no reply to send back. |
noReplyLogLevel
|
WARN
|
Camel 2.3: If sync is
enabled this option dictates MinaConsumer which logging
level to use when logging a there is no reply to send back.
Values are: FATAL, ERROR, INFO, DEBUG,
OFF . |
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;
for example, by creating a bean in the Spring XML file. Then use the
codec
option to specify the bean ID of your
codec.
In this sample, Apache 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("mina:tcp://localhost:6200?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("mina:tcp://localhost:6200?textline=true&sync=false", "Hello World"); assertMockEndpointsSatisfied();
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("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 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("mina:tcp://localhost:6201?textline=true&sync=true", "World"); assertEquals("Bye World", response);
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="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. 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" }
Configuration of Mina endpoints is now possible using regular Spring bean style configuration in the Spring DSL.
However, in the underlying Apache Mina toolkit, it is relatively
difficult to set up the acceptor and the connector, because you can
not use simple setters. To resolve this
difficulty, we 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"> <!-- we must provide a camel context so we refer to it by its id --> <constructor-arg index="0" ref="myCamel"/> </bean> <!-- 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"> <!-- and here we can pass it our configuration --> <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, as follows:
<route> <!-- here we route from or mina endpoint we have defined above --> <from ref="myMinaEndpoint"/> <to uri="mock:result"/> </route>
When acting as a server you sometimes want to close the session
when, for example, a client conversion is finished. To instruct
Apache 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("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(MinaConstants.MINA_CLOSE_SESSION_WHEN_COMPLETE, true); } });
Available since Apache Camel 2.1 You
can get the IoSession from the message header with this key
MinaEndpoint.HEADER_MINA_IOSESSION
, and also get
the local host address with the key
MinaEndpoint.HEADER_LOCAL_ADDRESS
and remote host
address with the key
MinaEndpoint.HEADER_REMOTE_ADDRESS
.
Available since Apache Camel 2.0
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
.
![]() | Note |
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If using the |
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 Apache Camel Mina may use 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, your 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"> <constructor-arg index="0" ref="camelContext" /> </bean> <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>