org.glassfish.web.valve

Interface GlassFishValve

All Known Implementing Classes:

AccessLogValve, AdHocContextValve, AuthenticatorBase, BasicAuthenticator, DigestAuthenticator, ErrorReportValve, ExtendedAccessLogValve, FormAuthenticator, GlassFishSingleSignOn, GlassFishValveAdapter, HASessionStoreValve, HASingleSignOn, JDBCAccessLogValve, NonLoginAuthenticator, PEAccessLogValve, PersistentValve, RemoteAddrValve, RemoteHostValve, RequestDumperValve, RequestFilterValve, SingleSignOn, SSLAuthenticator, ValveBase, WebdavFixValve

public interface GlassFishValve

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.

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.

Version:

$Revision: 1.2 $ $Date: 2005/12/08 01:27:21 $

Author:

Craig R. McClanahan, Gunnar Rjnning, Peter Donald

Field Summary

Fields

Modifier and Type	Field and Description
static int	END_PIPELINE A valve returns this value to indicate that no further processing of the request should take place (along the rest of the pipeline).
static int	INVOKE_NEXT A valve returns this value to indicate (to the pipeline) that the next valve in the pipeline can be invoked.

Method Summary

Modifier and Type	Method and Description
String	getInfo() Return descriptive information about this Valve implementation.
int	invoke(Request request, Response response) Perform request processing as required by this Valve.
void	postInvoke(Request request, Response response) Perform post-request processing as required by this Valve.

Field Detail

INVOKE_NEXT

static final int INVOKE_NEXT

A valve returns this value to indicate (to the pipeline) that the next valve in the pipeline can be invoked.

See Also:

Constant Field Values

END_PIPELINE

static final int END_PIPELINE

A valve returns this value to indicate that no further processing of the request should take place (along the rest of the pipeline). All valves that are function as 'basic' valves return this value as they are the 'last' valve in the pipeline. A valve (such as an authenticator) may return this value to stop a request from being processed further because the user/password could not be verified.

See Also:

Constant Field Values

Method Detail

getInfo

String getInfo()

Return descriptive information about this Valve implementation.

invoke

int invoke(Request request,
           Response response)
    throws IOException,
           javax.servlet.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 context.invokeNext().
• 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 invokeNext() method has returned.
• Perform any actions on the output stream associated with the specified Response after the invokeNext() method has returned.

Parameters:

request - The servlet request to be processed

response - The servlet response to be created

Returns:

INVOKE_NEXT or END_PIPELINE

Throws:

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

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

postInvoke

void postInvoke(Request request,
                Response response)
         throws IOException,
                javax.servlet.ServletException

Perform post-request processing as required by this Valve.

Parameters:

request - The servlet request to be processed

response - The servlet response to be created

Throws:

IOException - if an input/output error occurs

javax.servlet.ServletException - if a servlet error occurs