org.cometd.server.transport
Class LongPollingTransport

java.lang.Object
  org.cometd.server.AbstractServerTransport
      org.cometd.server.transport.HttpTransport
          org.cometd.server.transport.LongPollingTransport

All Implemented Interfaces:

ServerTransport, Transport

Direct Known Subclasses:

JSONPTransport, JSONTransport

public abstract class LongPollingTransport
extends HttpTransport

Abstract Long Polling Transport.

Transports based on this class can be configured with servlet init parameters:

browserId

The Cookie name used to save a browser ID.

maxSessionsPerBrowser

The maximum number of long polling sessions allowed per browser.

multiSessionInterval

The polling interval to use once max session per browser is exceeded.

autoBatch

If true a batch will be automatically created to span the handling of messages received from a session.

allowMultiSessionsNoBrowser

Allows multiple sessions even when the browser identifier cannot be retrieved.

Nested Class Summary

Nested classes/interfaces inherited from class org.cometd.server.AbstractServerTransport

AbstractServerTransport.OneTimeScheduler, AbstractServerTransport.Scheduler

Field Summary

static String	ALLOW_MULTI_SESSIONS_NO_BROWSER_OPTION
static String	AUTOBATCH_OPTION
static String	BROWSER_ID_OPTION
static String	MAX_SESSIONS_PER_BROWSER_OPTION
static String	MULTI_SESSION_INTERVAL_OPTION
static String	PREFIX

Fields inherited from class org.cometd.server.transport.HttpTransport

JSON_DEBUG_OPTION, MESSAGE_PARAM

Fields inherited from class org.cometd.server.AbstractServerTransport

INTERVAL_OPTION, MAX_INTERVAL_OPTION, MAX_LAZY_OPTION, META_CONNECT_DELIVERY_OPTION, TIMEOUT_OPTION

Constructor Summary

protected

LongPollingTransport(BayeuxServerImpl bayeux, String name)

Method Summary

protected abstract void	complete(PrintWriter writer)
protected void	decBrowserId(String browserId)
protected void	doSweep() Sweep the transport for old Browser IDs
protected String	findBrowserId(javax.servlet.http.HttpServletRequest request)
void	handle(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)
protected void	handleJSONParseException(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, String json, Throwable exception)
protected boolean	incBrowserId(String browserId) Increment the browser ID count.
protected void	init() Initialise the transport.
protected abstract boolean	isAlwaysFlushingAfterHandle()
protected abstract PrintWriter	send(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response, PrintWriter writer, ServerMessage message)
protected String	setBrowserId(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response)

Methods inherited from class org.cometd.server.transport.HttpTransport

accept, getContext, getCurrentLocalAddress, getCurrentRemoteAddress, getCurrentRequest, parseMessages, setCurrentRequest

Methods inherited from class org.cometd.server.AbstractServerTransport

getAdvice, getBayeux, getInterval, getMaxInterval, getMaxLazyTimeout, getName, getOption, getOption, getOption, getOption, getOption, getOptionNames, getOptionPrefix, getTimeout, isMetaConnectDeliveryOnly, setAdvice, setInterval, setMaxInterval, setMaxLazyTimeout, setMetaConnectDeliveryOnly, setOption, setOptionPrefix, setTimeout

Methods inherited from class java.lang.Object

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

Field Detail

PREFIX

public static final String PREFIX

See Also:

Constant Field Values

BROWSER_ID_OPTION

public static final String BROWSER_ID_OPTION

See Also:

Constant Field Values

MAX_SESSIONS_PER_BROWSER_OPTION

public static final String MAX_SESSIONS_PER_BROWSER_OPTION

See Also:

Constant Field Values

MULTI_SESSION_INTERVAL_OPTION

public static final String MULTI_SESSION_INTERVAL_OPTION

See Also:

Constant Field Values

AUTOBATCH_OPTION

public static final String AUTOBATCH_OPTION

See Also:

Constant Field Values

ALLOW_MULTI_SESSIONS_NO_BROWSER_OPTION

public static final String ALLOW_MULTI_SESSIONS_NO_BROWSER_OPTION

See Also:

Constant Field Values

Constructor Detail

LongPollingTransport

protected LongPollingTransport(BayeuxServerImpl bayeux,
                               String name)

Method Detail

init

protected void init()

Description copied from class: AbstractServerTransport

Initialise the transport. Initialise the transport, resolving default and direct options. After the call to init, the #getMutableOptions() set should be reset to reflect only the options that can be changed on a running transport. This implementation clears the mutable options set.

Overrides:

init in class HttpTransport

findBrowserId

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

setBrowserId

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

incBrowserId

protected boolean incBrowserId(String browserId)

Increment the browser ID count.

Parameters:

browserId - the browser ID to increment the count for

Returns:

true if the browser ID count is below the max sessions per browser value. If false is returned, the count is not incremented.

decBrowserId

protected void decBrowserId(String browserId)

handle

public void handle(javax.servlet.http.HttpServletRequest request,
                   javax.servlet.http.HttpServletResponse response)
            throws IOException,
                   javax.servlet.ServletException

Specified by:

handle in class HttpTransport

Throws:

IOException

javax.servlet.ServletException

handleJSONParseException

protected void handleJSONParseException(javax.servlet.http.HttpServletRequest request,
                                        javax.servlet.http.HttpServletResponse response,
                                        String json,
                                        Throwable exception)
                                 throws javax.servlet.ServletException,
                                        IOException

Throws:

javax.servlet.ServletException

IOException

doSweep

protected void doSweep()

Sweep the transport for old Browser IDs

Overrides:

doSweep in class AbstractServerTransport

See Also:

AbstractServerTransport.doSweep()

isAlwaysFlushingAfterHandle

protected abstract boolean isAlwaysFlushingAfterHandle()

Returns:

true if the transport always flushes at the end of a call to handle(HttpServletRequest, HttpServletResponse).

send

protected abstract PrintWriter send(javax.servlet.http.HttpServletRequest request,
                                    javax.servlet.http.HttpServletResponse response,
                                    PrintWriter writer,
                                    ServerMessage message)
                             throws IOException

Throws:

IOException

complete

protected abstract void complete(PrintWriter writer)
                          throws IOException

Throws:

IOException