Package org.apache.catalina
Interface Valve
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- All Known Subinterfaces:
ClusterValve
- All Known Implementing Classes:
AbstractAccessLogValve,AccessLogValve,AuthenticatorBase,BasicAuthenticator,ClusterSingleSignOn,CrawlerSessionManagerValve,DigestAuthenticator,ErrorReportValve,ExtendedAccessLogValve,FormAuthenticator,JDBCAccessLogValve,JvmRouteBinderValve,LoadBalancerDrainingValve,NonLoginAuthenticator,PersistentValve,RemoteAddrValve,RemoteCIDRValve,RemoteHostValve,RemoteIpValve,ReplicationValve,RequestFilterValve,RewriteValve,SemaphoreValve,SingleSignOn,SpnegoAuthenticator,SSLAuthenticator,SSLValve,StuckThreadDetectionValve,ValveBase
public interface ValveA Valve is a request processing component associated with a particular Container. A series of Valves are generally associated with each other into a Pipeline. The detailed contract for a Valve is included in the description of the
HISTORICAL NOTE: The "Valve" name was assigned to this concept because a valve is what you use in a real world pipeline to control and/or modify flows through it.invoke()method below.- Author:
- Craig R. McClanahan, Gunnar Rjnning, Peter Donald
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Method Summary
All Methods Instance Methods Abstract Methods Modifier and Type Method Description voidbackgroundProcess()Execute a periodic task, such as reloading, etc.ValvegetNext()voidinvoke(Request request, Response response)Perform request processing as required by this Valve.booleanisAsyncSupported()voidsetNext(Valve valve)Set the next Valve in the pipeline containing this Valve.
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Method Detail
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getNext
Valve getNext()
- Returns:
- the next Valve in the pipeline containing this Valve, if any.
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setNext
void setNext(Valve valve)
Set the next Valve in the pipeline containing this Valve.- Parameters:
valve- The new next valve, ornullif none
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backgroundProcess
void backgroundProcess()
Execute a periodic task, such as reloading, etc. This method will be invoked inside the classloading context of this container. Unexpected throwables will be caught and logged.
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invoke
void invoke(Request request, Response response) throws IOException, ServletException
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.
- Parameters:
request- The servlet request to be processedresponse- The servlet response to be created- Throws:
IOException- if an input/output error occurs, or is thrown by a subsequently invoked Valve, Filter, or ServletServletException- if a servlet error occurs, or is thrown by a subsequently invoked Valve, Filter, or Servlet
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isAsyncSupported
boolean isAsyncSupported()
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