Package org.apache.catalina
Interface Valve
- All Known Subinterfaces:
ClusterValve
- All Known Implementing Classes:
AbstractAccessLogValve
,AccessLogValve
,AuthenticatorBase
,BasicAuthenticator
,ClusterSingleSignOn
,CrawlerSessionManagerValve
,DigestAuthenticator
,ErrorReportValve
,ExtendedAccessLogValve
,FormAuthenticator
,JDBCAccessLogValve
,JsonAccessLogValve
,JsonErrorReportValve
,JvmRouteBinderValve
,LoadBalancerDrainingValve
,NonLoginAuthenticator
,PersistentValve
,ProxyErrorReportValve
,RemoteAddrValve
,RemoteCIDRValve
,RemoteHostValve
,RemoteIpValve
,ReplicationValve
,RequestFilterValve
,RewriteValve
,SemaphoreValve
,SingleSignOn
,SpnegoAuthenticator
,SSLAuthenticator
,SSLValve
,StuckThreadDetectionValve
,ValveBase
public interface Valve
A 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 invoke()
method below.
- Author:
- Craig R. McClanahan, Gunnar Rjnning, Peter Donald
-
Method Summary
Modifier and TypeMethodDescriptionvoid
Execute a periodic task, such as reloading, etc.getNext()
Returns the next Valve in this pipeline, ornull
if this is the last Valve in the pipeline.void
Perform request processing as required by this Valve.boolean
void
Set the next Valve in the pipeline containing this Valve.
-
Method Details
-
getNext
Valve getNext()Returns the next Valve in this pipeline, ornull
if this is the last Valve in the pipeline.- Returns:
- the next Valve in the pipeline containing this Valve, or
null
if this is the last Valve in the pipeline.
-
setNext
Set the next Valve in the pipeline containing this Valve.- Parameters:
valve
- The new next valve, ornull
if none
-
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. -
invoke
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
-
isAsyncSupported
boolean isAsyncSupported()
-