Interceptors???

Scruff

Can anyone point me to a good resource for programmng interseptors through java?
Need some info on the bsic concepts behind them as well as code examples.

Ta!

Hobbes

Whats an interseptor?

Scruff

as far as i can tell its an object that listens on a port and "intercepts" incoming traffic, does some processing and passes out the result\modified traffic to another process.

jessy

Never herd of an interseptor. Sounds like a cross between a Firewall and a packet Sniffer.

happydude13

I think what you are referring to is an 'interceptor'

Perhaps as in the Pattern,

or in simple terms, a way of doing something.

A high level software engineering concept to promote

the re use of ideas etc..

Martyr

Could you write some kind of minimal debugger, and then set breakpoints
on calls to socket functions?..then as you say "intercept"
the data, before continuing execution where the data will be processed
by the main application.

I don't know enough about java, but this is what i'm thinking might work.

secret_squirrel

Not a java programmer but that sounds like what I would call a 'listener' it listens to traffic arriving on a particular port - analyses it then passed it on to a backend.

Fundamental part of any client-server app. Would have thought you could get them as prepackaged components theses days. Definately sounds like a case of re-inventing the wheel to me.

Code reuse is everything. Just remember to avoid giving Kanagaroos SAM's.

Dizz

Interceptors - essential for enterprise apps. Read up on how EJB's implement transparent security, transactions - they use an interceptor design pattern to implement the addition/removal of such services.
Have a read on Axis handlers - handlers are akin to interceptors - see http://archive.devx.com/java/wrox/7159_chap04.pdf (free chapter)
CORBA also uses interceptors to implement security services - look about on omg.org if you don't mind a crappy layout.
Googling on the above terms will yield lots of info you can grok.

The chain of responsibility design pattern is very much similar to an interceptor design and pretty much implements it. (http://www.javaworld.com/javaworld/jw-08-2003/jw-0829-designpatterns.html)

Most basic dea behind interceptors...
void doIt(){

pre_security_check();
do_bank_xa();
post_security_check();
}

HTH

Dizz