sunlabs.brazil.filter

Class SessionFilter

public class SessionFilter extends Object implements Filter

Filter to manage browser sessions using browser cookies or URL rewriting as needed. This should be used as the last filter in the filter chain. It attempts to use browser cookies. If they don't work, it rewrites the URL's instead, tacking the session info onto the end of the URL.

This Filter works by first examining the request as a handler. If the request contains an ID, either in the "browser cookie" or written into the URL, the session ID is extracted. In the id-in-the-url case, the ID is removed from the URL. When called later as a filter, the SessionFilter rewrites all relevent URL's in the page to incorporate the ID.

If an ID can't be found either in the cookie or URL, a couple the session creation sequence starts. First, the browser is send a "set-cookie" request along with a redirect that contains the cookie value encoded into the redirected URL. When the browser follows the redirect, the request is examined to se if the cookie value was sent. If so, the browser is redirected back to the original URL, and normal "cookie" processing takes place. If no cookie is found, the browser is redirected back to the original URL, modified to embed the ID into it, and normal URL session rewriting takes place.

The following server properties are used:

cookie
The name of the cookie to use (defaults to "cookie"). If the name is "none", then no cookies are used. Instead, session rewriting will occur for every session.
session
The name of the request property that the Session ID will be stored in, to be passed to downstream handler. The default value is "SessionID". If the session property is set, and not empty, then no processing is done.
persist
If set, cookies persist across browser sessions. If cookies are disabled, no persistence is available.
cookiePrefix
The URL prefix for which the cookie applies. Defaults to "/".
suffix
A regular expression that matches url suffix we process. Defaults to html|xml|txt.
The Following request properties are set:
gotCookie
An id was retrieved out of a cookie header
UrlID
Set to the string tacked onto the end of each URL, if session ID's are managed by URL rewriting. If cookies are used, this is set to the empty string.

Version: 2.4

Author: Stephen Uhler

Field Summary
StringcookieName
Stringencoding
booleanpersist
StringredirectToken
Stringsession
StringurlSep
Method Summary
byte[]filter(Request request, MimeHeaders headers, byte[] content)
Rewrite all the url's, adding the session id to the end
booleaninit(Server server, String propsPrefix)
booleanrespond(Request request)
This is called by the filterHandler before the content generation step.
booleanshouldFilter(Request request, MimeHeaders headers)
We have the results, only filter if html and we're rewriting

Field Detail

cookieName

public String cookieName

encoding

public String encoding

persist

public boolean persist

redirectToken

public String redirectToken

session

public String session

urlSep

public String urlSep

Method Detail

filter

public byte[] filter(Request request, MimeHeaders headers, byte[] content)
Rewrite all the url's, adding the session id to the end

init

public boolean init(Server server, String propsPrefix)

respond

public boolean respond(Request request)
This is called by the filterHandler before the content generation step. It is responsible for extracting the session information, then (if required) restoring the URL's to their original form. It tries relatively hard to use cookies if they are available through a series or redirects.

shouldFilter

public boolean shouldFilter(Request request, MimeHeaders headers)
We have the results, only filter if html and we're rewriting