org.apache.catalina.valves

Class CrawlerSessionManagerValve

java.lang.Object

org.apache.catalina.util.LifecycleBase

org.apache.catalina.util.LifecycleMBeanBase

org.apache.catalina.valves.ValveBase

org.apache.catalina.valves.CrawlerSessionManagerValve

All Implemented Interfaces:

EventListener, MBeanRegistration, HttpSessionBindingListener, Contained, JmxEnabled, Lifecycle, Valve

public class CrawlerSessionManagerValve
extends ValveBase
implements HttpSessionBindingListener

Web crawlers can trigger the creation of many thousands of sessions as they crawl a site which may result in significant memory consumption. This Valve ensures that crawlers are associated with a single session - just like normal users - regardless of whether or not they provide a session token with their requests.

Nested Class Summary

Nested classes/interfaces inherited from interface org.apache.catalina.Lifecycle

Lifecycle.SingleUse

Field Summary

Fields inherited from class org.apache.catalina.valves.ValveBase

asyncSupported, container, containerLog, next, sm

Fields inherited from class org.apache.catalina.util.LifecycleMBeanBase

mserver

Fields inherited from interface org.apache.catalina.Lifecycle

AFTER_DESTROY_EVENT, AFTER_INIT_EVENT, AFTER_START_EVENT, AFTER_STOP_EVENT, BEFORE_DESTROY_EVENT, BEFORE_INIT_EVENT, BEFORE_START_EVENT, BEFORE_STOP_EVENT, CONFIGURE_START_EVENT, CONFIGURE_STOP_EVENT, PERIODIC_EVENT, START_EVENT, STOP_EVENT

Constructor Summary

Constructors

Constructor and Description
CrawlerSessionManagerValve() Specifies a default constructor so async support can be configured.

Method Summary

Modifier and Type	Method and Description
Map<String,String>	getClientIpSessionId()
String	getCrawlerUserAgents()
int	getSessionInactiveInterval()
protected void	initInternal() Sub-classes wishing to perform additional initialization should override this method, ensuring that super.initInternal() is the first call in the overriding method.
void	invoke(Request request, Response response) Perform request processing as required by this Valve.
void	setCrawlerUserAgents(String crawlerUserAgents) Specify the regular expression (using Pattern) that will be used to identify crawlers based in the User-Agent header provided.
void	setSessionInactiveInterval(int sessionInactiveInterval) Specify the session timeout (in seconds) for a crawler's session.
void	valueUnbound(HttpSessionBindingEvent event) Notifies the object that it is being unbound from a session and identifies the session.

Methods inherited from class org.apache.catalina.valves.ValveBase

backgroundProcess, getContainer, getDomainInternal, getNext, getObjectNameKeyProperties, isAsyncSupported, setAsyncSupported, setContainer, setNext, startInternal, stopInternal, toString

Methods inherited from class org.apache.catalina.util.LifecycleMBeanBase

destroyInternal, getDomain, getObjectName, postDeregister, postRegister, preDeregister, preRegister, register, setDomain, unregister

Methods inherited from class org.apache.catalina.util.LifecycleBase

addLifecycleListener, destroy, findLifecycleListeners, fireLifecycleEvent, getState, getStateName, init, removeLifecycleListener, setState, setState, start, stop

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.http.HttpSessionBindingListener

valueBound

Constructor Detail

CrawlerSessionManagerValve

public CrawlerSessionManagerValve()

Specifies a default constructor so async support can be configured.

Method Detail

setCrawlerUserAgents

public void setCrawlerUserAgents(String crawlerUserAgents)

Specify the regular expression (using Pattern) that will be used to identify crawlers based in the User-Agent header provided. The default is ".*GoogleBot.*|.*bingbot.*|.*Yahoo! Slurp.*"

Parameters:

crawlerUserAgents - The regular expression using Pattern

getCrawlerUserAgents

public String getCrawlerUserAgents()

Returns:

The current regular expression being used to match user agents.

See Also:

setCrawlerUserAgents(String)

setSessionInactiveInterval

public void setSessionInactiveInterval(int sessionInactiveInterval)

Specify the session timeout (in seconds) for a crawler's session. This is typically lower than that for a user session. The default is 60 seconds.

Parameters:

sessionInactiveInterval - The new timeout for crawler sessions

getSessionInactiveInterval

public int getSessionInactiveInterval()

Returns:

The current timeout in seconds

See Also:

setSessionInactiveInterval(int)

getClientIpSessionId

public Map<String,String> getClientIpSessionId()

initInternal

protected void initInternal()
                     throws LifecycleException

Description copied from class: LifecycleMBeanBase

Sub-classes wishing to perform additional initialization should override this method, ensuring that super.initInternal() is the first call in the overriding method.

Overrides:

initInternal in class ValveBase

Throws:

LifecycleException

invoke

public void invoke(Request request,
                   Response response)
            throws IOException,
                   ServletException

Description copied from interface: Valve

Perform request processing as required by this Valve.

An individual Valve MAY perform the following actions, in the specified order:

• Examine and/or modify the properties of the specified Request and Response.
• Examine the properties of the specified Request, completely generate the corresponding Response, and return control to the caller.
• Examine the properties of the specified Request and Response, wrap either or both of these objects to supplement their functionality, and pass them on.
• If the corresponding Response was not generated (and control was not returned, call the next Valve in the pipeline (if there is one) by executing getNext().invoke().
• Examine, but not modify, the properties of the resulting Response (which was created by a subsequently invoked Valve or Container).

A Valve MUST NOT do any of the following things:

• Change request properties that have already been used to direct the flow of processing control for this request (for instance, trying to change the virtual host to which a Request should be sent from a pipeline attached to a Host or Context in the standard implementation).
• Create a completed Response AND pass this Request and Response on to the next Valve in the pipeline.
• Consume bytes from the input stream associated with the Request, unless it is completely generating the response, or wrapping the request before passing it on.
• Modify the HTTP headers included with the Response after the getNext().invoke() method has returned.
• Perform any actions on the output stream associated with the specified Response after the getNext().invoke() method has returned.

Specified by:

invoke in interface Valve

Parameters:

request - The servlet request to be processed

response - The servlet response to be created

Throws:

IOException - if an input/output error occurs, or is thrown by a subsequently invoked Valve, Filter, or Servlet

ServletException - if a servlet error occurs, or is thrown by a subsequently invoked Valve, Filter, or Servlet

valueUnbound

public void valueUnbound(HttpSessionBindingEvent event)

Description copied from interface: javax.servlet.http.HttpSessionBindingListener

Notifies the object that it is being unbound from a session and identifies the session. The default implementation is a NO-OP.

Specified by:

valueUnbound in interface HttpSessionBindingListener

Parameters:

event - the event that identifies the session

See Also:

HttpSessionBindingListener.valueBound(javax.servlet.http.HttpSessionBindingEvent)