/*
?*?Copyright?2005?Joe?Walker
?*
?*?Licensed?under?the?Apache?License?Version?2.0?（the?“License“）;
?*?you?may?not?use?this?file?except?in?compliance?with?the?License.
?*?You?may?obtain?a?copy?of?the?License?at
?*
?*?????http://www.apache.org/licenses/LICENSE-2.0
?*
?*?Unless?required?by?applicable?law?or?agreed?to?in?writing?software
?*?distributed?under?the?License?is?distributed?on?an?“AS?IS“?BASIS
?*?WITHOUT?WARRANTIES?OR?CONDITIONS?OF?ANY?KIND?either?express?or?implied.
?*?See?the?License?for?the?specific?language?governing?permissions?and
?*?limitations?under?the?License.
?*/
package?org.directwebremoting;

import?java.io.IOException;
import?java.lang.reflect.Method;

/**
?*?A?filter?is?a?way?to?insert?procesing?tasks?at?various?points?during?the
?*?processing?of?an?Ajax?call.
?*?
Example?filters:

?*?

?*?
Authentication

?*?
Latency?simulators

?*?
Data?cleansing?-?remove?private?data

?*?
Logging?filters?-?when?you?need?specific?logging?action

?*?

?*?@since?DWR?2.0
?*?@author?Joe?Walker?[joe?at?getahead?dot?ltd?dot?uk]
?*/
public?interface?AjaxFilter
{
????/**
?????*?The?doFilter?method?of?the?AjaxFilter?is?called?by?DWR?each
?????*?time?an?Ajax?request?is?made?on?a?method?that?this?filter?is?configured
?????*?against.?The?AjaxFilterChain?passed?in?to?this?method?allows
?????*?the?filter?to?pass?on?method?details?to?next?entity?in?the?chain.
?????*?
Typically?the?method?would?do?the?following:

?????*?

?????*?
Examine?the?request

?????*?
Optionally?alter?the?method?object?or?parameters

?????*?
Either?invoke?the?next?entity?in?the?chain?using?the?AjaxFilterChain
?????*?or?decide?to?take?some?other?action?instead.

?????*?
Optionally?modify?the?value?returned?to?the?user

?????*?
Take?some?other?action?（e.g.?logging）

?????*?

?????*?@param?obj?The?object?to?execute?the?method?on?（i.e.?‘this‘）
?????*?@param?method?The?method?to?execute
?????*?@param?params?The?parameters?to?the?method?call
?????*?@param?chain?Allow?the?request?to?be?passed?on
?????*?@return?The?results?of?the?method?execution
?????*?@throws?IOException?When?some?I/O?error?occurs
?????*?@throws?Exception?When?some?processing?goes?wrong
?????*/
????public?object?doFilter（object?obj?Method?method?object[]?params?AjaxFilterChain?chain）?throws?Exception;
}