Hi,
A MINA filter is not exactly like a servlet filter because a servlet filter
only processes data as it is received.
MINA filters process events - such as data coming from the network, or a
request to write data. They are arranged in a filter chain. However the key
thing to know is that events are not all processed in the same order by the
filter chain. If you view the filter chain as going from top to bottom,
reads are processed from top to bottom but write requests are processed
bottom to top. It's a layered model.
To see why this is useful, consider an application where you want to
encrypt your data, and also support encoding and decoding the bytes into
Java objects. You would have two filters: encryptor/decryptor then codec.
For reads you want to decrypt first then decode, and for writes you want to
encode then encrypt. The layered model makes this easy.
For your application, it may be simpler to use a codec to handle the
encoding/decoding so that your handler only has to deal with Java objects.
See org.apache.mina.filter.codec.ProtocolCodecFilter for details.
Also unless your codec is extremely simple, you should consider using the
thread pool filter to improve throughput.
Robert
|---------+---------------------------->
| | Samuel Doyle |
| | <[EMAIL PROTECTED]|
| | om> |
| | |
| | 08/03/2006 21:49 |
| | Please respond to|
| | mina-dev |
| | |
|---------+---------------------------->
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| To: [email protected]
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| cc:
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| Subject: Using filters in Mina
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Hi,
I'm not very familiar with filters myself and started
looking into them. I see much documentation on them
for use in Servlets but how does it vary in Mina? I've
basically designed a proxy server using Mina to act as
a proxy for routing requests between two very
different systems. The mechanism I use is in
attaching specific objects to the sessions and would
use these in encoding and decoding of the packet data
in the messageReceived methods of my handlers. I was
wondering if this is something that would be better
implemented as a filter? If so what is the best
approach?
Thanks, S.D.
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