org.cometd.server
Class AbstractCometdServlet

java.lang.Object
  extended by javax.servlet.GenericServlet
      extended by org.cometd.server.AbstractCometdServlet
All Implemented Interfaces:
java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig
Direct Known Subclasses:
ContinuationCometdServlet

public abstract class AbstractCometdServlet
extends javax.servlet.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.cometd.server.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
protected  AbstractBayeux _bayeux
           
static java.lang.String BROWSER_ID
           
static java.lang.String CLIENT_ATTR
           
static java.lang.String HTTP_CLIENT_ID
           
static java.lang.String MESSAGE_PARAM
           
static java.lang.String TRANSPORT_ATTR
           
static java.lang.String TUNNEL_INIT_PARAM
           
 
Constructor Summary
AbstractCometdServlet()
           
 
Method Summary
protected  java.lang.String findBrowserId(javax.servlet.http.HttpServletRequest request)
           
 AbstractBayeux getBayeux()
           
protected  Message[] getMessages(javax.servlet.http.HttpServletRequest request)
           
 void init()
           
protected abstract  AbstractBayeux newBayeux()
           
protected abstract  void service(javax.servlet.http.HttpServletRequest req, javax.servlet.http.HttpServletResponse resp)
           
 void service(javax.servlet.ServletRequest req, javax.servlet.ServletResponse resp)
           
protected  java.lang.String setBrowserId(javax.servlet.http.HttpServletRequest request, javax.servlet.http.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 java.lang.String CLIENT_ATTR
See Also:
Constant Field Values

TRANSPORT_ATTR

public static final java.lang.String TRANSPORT_ATTR
See Also:
Constant Field Values

MESSAGE_PARAM

public static final java.lang.String MESSAGE_PARAM
See Also:
Constant Field Values

TUNNEL_INIT_PARAM

public static final java.lang.String TUNNEL_INIT_PARAM
See Also:
Constant Field Values

HTTP_CLIENT_ID

public static final java.lang.String HTTP_CLIENT_ID
See Also:
Constant Field Values

BROWSER_ID

public static final java.lang.String BROWSER_ID
See Also:
Constant Field Values

_bayeux

protected AbstractBayeux _bayeux
Constructor Detail

AbstractCometdServlet

public AbstractCometdServlet()
Method Detail

getBayeux

public AbstractBayeux getBayeux()

newBayeux

protected abstract AbstractBayeux newBayeux()

init

public void init()
          throws javax.servlet.ServletException
Overrides:
init in class javax.servlet.GenericServlet
Throws:
javax.servlet.ServletException

service

protected abstract void service(javax.servlet.http.HttpServletRequest req,
                                javax.servlet.http.HttpServletResponse resp)
                         throws javax.servlet.ServletException,
                                java.io.IOException
Throws:
javax.servlet.ServletException
java.io.IOException

service

public void service(javax.servlet.ServletRequest req,
                    javax.servlet.ServletResponse resp)
             throws javax.servlet.ServletException,
                    java.io.IOException
Specified by:
service in interface javax.servlet.Servlet
Specified by:
service in class javax.servlet.GenericServlet
Throws:
javax.servlet.ServletException
java.io.IOException

findBrowserId

protected java.lang.String findBrowserId(javax.servlet.http.HttpServletRequest request)

setBrowserId

protected java.lang.String setBrowserId(javax.servlet.http.HttpServletRequest request,
                                        javax.servlet.http.HttpServletResponse response)

getMessages

protected Message[] getMessages(javax.servlet.http.HttpServletRequest request)
                         throws java.io.IOException
Throws:
java.io.IOException


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