sunlabs.brazil.proxy
Class CookieFilter

java.lang.Object
  sunlabs.brazil.proxy.CookieFilter (view source)

All Implemented Interfaces:

Filter, Handler

public class CookieFilter
extends Object
implements Filter

The CookieFilter keeps a record of all the browser cookies associated with a given session. This can be used to make the user's cookies "mobile" as follows. A user's cookies are normally stored with the browser being used, on the user's machine. If the user runs a different browser or goes to a different machine, the user's cookies will not be there. Instead, the user can access the web via a proxy that keeps all their cookies. No matter which browser the user chooses or machine the user is at, a proxy running with the CookieFilter will automatically remember and add in their appropriate cookies. The CookieFilter also supports multiple, concurrent users, keeping each user's cookies separate.

• All "Set-Cookie" HTTP response headers are filtered out and saved in the local storage. "Set-Cookie" headers are not transmitted back to the client.
• Requests from the client have the appropriate "Cookie" headers added.
• Users can retrieve, edit, and delete their own cookies.
• JavaScript code that sets cookies is not handled by this filter, since the code only runs on the client computer, not on the proxy. For instance: document.cookie = "userid=778287312". Any and all Javascript is passed unchanged by this filter.
• This filter works in both a session-based and a non-session-based fashion. If sessions are used, cookies are kept with respect to the session associated with a user. If sessions are not used, all cookies are kept in one pile for all users. The latter case is valid if, say, only one user is using the proxy running the CookieFilter.

Properties:

session

The request property to find the session id. Defaults to "SessionID"

nosession

The name of the session to use if no session id is found. defaults to "common".

admin

A URL prefix that causes status information to be placed in the request properties.

Nested Class Summary

static class

CookieFilter.CookieInfo Store information about a cookie

Field Summary

String	admin
String	nosession
String	session

Constructor Summary

CookieFilter()

Method Summary

byte[]	filter(Request request, MimeHeaders headers, byte[] content) Returns the original content, since this filter does not change content; it changes the headers.
boolean	init(Server server, String prefix) Initializes the handler.
boolean	respond(Request request) Responds to an HTTP request.
boolean	shouldFilter(Request request, MimeHeaders headers) Saves all "Set-Cookie" headers from the target in the client's local storage, then removes those headers before allowing the response to go back to the client.

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

session

public String session

nosession

public String nosession

admin

public String admin

Constructor Detail

CookieFilter

public CookieFilter()

Method Detail

init

public boolean init(Server server,
                    String prefix)

Description copied from interface: Handler

Initializes the handler.

Specified by:

init in interface Handler

Parameters:

server - The HTTP server that created this Handler. Typical Handlers will use Server.props to obtain run-time configuration information.

prefix - The handlers name. The string this Handler may prepend to all of the keys that it uses to extract configuration information from Server.props. This is set (by the Server and ChainHandler) to help avoid configuration parameter namespace collisions.

Returns:

true if this Handler initialized successfully, false otherwise. If false is returned, this Handler should not be used.

respond

public boolean respond(Request request)
                throws IOException

Description copied from interface: Handler

Responds to an HTTP request.

Specified by:

respond in interface Handler

Parameters:

request - The Request object that represents the HTTP request.

Returns:

true if the request was handled. A request was handled if a response was supplied to the client, typically by calling Request.sendResponse() or Request.sendError.

Throws:

IOException - if there was an I/O error while sending the response to the client. Typically, in that case, the Server will (try to) send an error message to the client and then close the client's connection.

The IOException should not be used to silently ignore problems such as being unable to access some server-side resource (for example getting a FileNotFoundException due to not being able to open a file). In that case, the Handler's duty is to turn that IOException into a HTTP response indicating, in this case, that a file could not be found.

shouldFilter

public boolean shouldFilter(Request request,
                            MimeHeaders headers)

Saves all "Set-Cookie" headers from the target in the client's local storage, then removes those headers before allowing the response to go back to the client. The client never sees cookies on their local machine.

Specified by:

shouldFilter in interface Filter

Parameters:

request - The in-progress HTTP request.

headers - The MIME headers generated by the wrapped Handler.

Returns:

true if this filter would like to examine and possibly rewrite the content, false otherwise.

filter

public byte[] filter(Request request,
                     MimeHeaders headers,
                     byte[] content)

Returns the original content, since this filter does not change content; it changes the headers.

Specified by:

filter in interface Filter

Parameters:

request - The finished HTTP request.

headers - The MIME headers generated by the Handler.

content - The output from the Handler that this Filter may rewrite.

Returns:

The rewritten content. The Filter may return the original content unchanged. The Filter may return null to indicate that the FilterHandler should stop processing the request and should not return any content to the client.