org.mortbay.cometd
Class AbstractCometdServlet

java.lang.Object
  javax.servlet.GenericServlet
      org.mortbay.cometd.AbstractCometdServlet

All Implemented Interfaces:

Serializable, Servlet, ServletConfig

Direct Known Subclasses:

ContinuationCometdServlet

public abstract class AbstractCometdServlet
extends GenericServlet

Cometd Filter Servlet implementing the AbstractBayeux protocol. The Servlet can be initialized with a json file mapping channels to DataFilter definitions. The servlet init parameter "filters" should point to a webapplication resource containing a JSON array of filter definitions. For example:

  [
    {
      "channels": "/**",
      "class"   : "org.mortbay.cometd.filter.NoMarkupFilter",
      "init"    : {}
    }
  ]
 

The following init parameters can be used to configure the servlet:

timeout

The server side poll timeout in milliseconds (default 250000). This is how long the server will hold a reconnect request before responding.

interval

The client side poll timeout in milliseconds (default 0). How long a client will wait between reconnects

maxInterval

The max client side poll timeout in milliseconds (default 30000). A client will be removed if a connection is not received in this time.

maxLazyLatency

The max time in ms(default 0) that a client with lazy messages will wait before sending a response. If 0, then the client will wait until the next timeout or non-lazy message.

multiFrameInterval

the client side poll timeout if multiple connections are detected from the same browser (default 1500).

JSONCommented

If "true" then the server will accept JSON wrapped in a comment and will generate JSON wrapped in a comment. This is a defence against Ajax Hijacking.

filters

the location of a JSON file describing DataFilter instances to be installed

requestAvailable

If true, the current request is made available via the AbstractBayeux.getCurrentRequest() method

loglevel

0=none, 1=info, 2=debug

refsThreshold

The number of message refs at which the a single message response will be cached instead of being generated for every client delivered to. Done to optimize a single message being sent to multiple clients.

Author:

gregw, aabeling: added JSONP transport

See Also:

AbstractBayeux}, ChannelId}, Serialized Form

Field Summary

static int	__DEFAULT_REFS_THRESHOLD
protected AbstractBayeux	_bayeux
protected int	_refsThreshold
static String	BROWSER_ID
static String	CLIENT_ATTR
static String	HTTP_CLIENT_ID
static String	MESSAGE_PARAM
static String	TRANSPORT_ATTR
static String	TUNNEL_INIT_PARAM

Constructor Summary

AbstractCometdServlet()

Method Summary

protected String	findBrowserId(HttpServletRequest request)
AbstractBayeux	getBayeux()
protected org.cometd.Message[]	getMessages(HttpServletRequest request)
void	init()
protected abstract AbstractBayeux	newBayeux()
protected abstract void	service(HttpServletRequest req, HttpServletResponse resp)
void	service(ServletRequest req, ServletResponse resp)
protected String	setBrowserId(HttpServletRequest request, HttpServletResponse response)

Methods inherited from class javax.servlet.GenericServlet

destroy, getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletInfo, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Field Detail

CLIENT_ATTR

public static final String CLIENT_ATTR

See Also:

Constant Field Values

TRANSPORT_ATTR

public static final String TRANSPORT_ATTR

See Also:

Constant Field Values

MESSAGE_PARAM

public static final String MESSAGE_PARAM

See Also:

Constant Field Values

TUNNEL_INIT_PARAM

public static final String TUNNEL_INIT_PARAM

See Also:

Constant Field Values

HTTP_CLIENT_ID

public static final String HTTP_CLIENT_ID

See Also:

Constant Field Values

BROWSER_ID

public static final String BROWSER_ID

See Also:

Constant Field Values

_bayeux

protected AbstractBayeux _bayeux

__DEFAULT_REFS_THRESHOLD

public static final int __DEFAULT_REFS_THRESHOLD

See Also:

Constant Field Values

_refsThreshold

protected int _refsThreshold

Constructor Detail

AbstractCometdServlet

public AbstractCometdServlet()

Method Detail

getBayeux

public AbstractBayeux getBayeux()

newBayeux

protected abstract AbstractBayeux newBayeux()

init

public void init()
          throws ServletException

Overrides:

init in class GenericServlet

Throws:

ServletException

service

protected abstract void service(HttpServletRequest req,
                                HttpServletResponse resp)
                         throws ServletException,
                                IOException

Throws:

ServletException

IOException

service

public void service(ServletRequest req,
                    ServletResponse resp)
             throws ServletException,
                    IOException

Specified by:

service in interface Servlet

Specified by:

service in class GenericServlet

Throws:

ServletException

IOException

findBrowserId

protected String findBrowserId(HttpServletRequest request)

setBrowserId

protected String setBrowserId(HttpServletRequest request,
                              HttpServletResponse response)

getMessages

protected org.cometd.Message[] getMessages(HttpServletRequest request)
                                    throws IOException

Throws:

IOException