er.extensions.appserver

Class ERXDelayedRequestHandler

java.lang.Object

com.webobjects.appserver.WORequestHandler

er.extensions.appserver.ERXDelayedRequestHandler

public class ERXDelayedRequestHandler
extends com.webobjects.appserver.WORequestHandler

When this request handler is set via registerRequestHandlerForKey(new ERXDelayedRequestHandler(), ERXDelayedRequestHandler.KEY), then a request that takes too long is automatically detached and a poor man's long response is returned. It is pretty cool in that:

• the users don't get the adaptor timeout and won't get redirected to an instance that doesn't know anything about the session.
• the users get immediate feedback with no code changes on your part.
• the handler tries to cancels active requests that take too long (default is maxRequestTimeSeconds*5), which should mean no more session deadlocks.
• you can subclass this handler to provide for better responses.
• you can provide a simple style sheet for the default refresh page.

Author:

ak

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	ERXDelayedRequestHandler.DelayedRequest Helper to wrap a future and the accompanying request.

Field Summary

Fields

Modifier and Type	Field and Description
static String	KEY

Fields inherited from class com.webobjects.appserver.WORequestHandler

DidHandleRequestNotification

Constructor Summary

Constructors

Constructor and Description
ERXDelayedRequestHandler() Creates a handler with the default values of 5 second refresh and 5 seconds maxRequestTime.
ERXDelayedRequestHandler(int refreshTimeSeconds, int maxRequestTimeSeconds) Creates a handler with the supplied values for refreshTimeSeconds and maxRequestTimeSeconds.
ERXDelayedRequestHandler(int refreshTimeSeconds, int maxRequestTimeSeconds, int cancelRequestAfterSeconds) Creates a handler with the supplied values for refreshTimeSeconds, maxRequestTimeSeconds and maxRequestTimeSeconds.
ERXDelayedRequestHandler(int refreshTimeSeconds, int maxRequestTimeSeconds, int cancelRequestAfterSeconds, String cssUrl) Creates a request handler instance.

Method Summary

Modifier and Type	Method and Description
NSArray<ERXDelayedRequestHandler.DelayedRequest>	activeRequests() Returns all active delayed requests.
protected boolean	canHandleRequest(com.webobjects.appserver.WORequest request) Returns true if the request handler key can be handled.
protected com.webobjects.appserver.WOResponse	createErrorResponse(com.webobjects.appserver.WORequest request) Create an error page when the future wasn't found anymore.
protected com.webobjects.appserver.WOResponse	createRefreshResponse(com.webobjects.appserver.WORequest request, String url) Create a refresh page.
protected com.webobjects.appserver.WOResponse	createStoppedResponse(com.webobjects.appserver.WORequest request) Create a "stopped" page.
protected String	cssUrl(com.webobjects.appserver.WORequest request)
protected com.webobjects.appserver.WOResponse	handle(com.webobjects.appserver.WORequest request, ERXDelayedRequestHandler.DelayedRequest delayedRequest, String id) Override to handle specific actions for the current future.
com.webobjects.appserver.WOResponse	handleRequest(com.webobjects.appserver.WORequest request) Handles the request and returns the applicable response.
protected int	maxRequestTimeMillis() Returns the maximum time in milliseconds for allowed for a request before returning the message page.
protected int	refresh() Returns the refresh time in seconds for the message page.

Methods inherited from class com.webobjects.appserver.WORequestHandler

toString

Methods inherited from class java.lang.Object

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

Field Detail

KEY

public static String KEY

Constructor Detail

ERXDelayedRequestHandler

public ERXDelayedRequestHandler(int refreshTimeSeconds,
                                int maxRequestTimeSeconds,
                                int cancelRequestAfterSeconds,
                                String cssUrl)

Creates a request handler instance.

Parameters:

refreshTimeSeconds - time in seconds for the refresh of the page

maxRequestTimeSeconds - time in seconds that a request can take at most before the delayed page is returned

cancelRequestAfterSeconds - time in seconds that a request can take at most before it is cancelled

cssUrl - url for a style sheet for the message page

ERXDelayedRequestHandler

public ERXDelayedRequestHandler(int refreshTimeSeconds,
                                int maxRequestTimeSeconds,
                                int cancelRequestAfterSeconds)

Creates a handler with the supplied values for refreshTimeSeconds, maxRequestTimeSeconds and maxRequestTimeSeconds.

Parameters:

refreshTimeSeconds -

maxRequestTimeSeconds -

cancelRequestAfterSeconds -

ERXDelayedRequestHandler

public ERXDelayedRequestHandler(int refreshTimeSeconds,
                                int maxRequestTimeSeconds)

Creates a handler with the supplied values for refreshTimeSeconds and maxRequestTimeSeconds. cancelRequestAfterSeconds is set o 5*maxRequestTimeSeconds.

Parameters:

refreshTimeSeconds -

maxRequestTimeSeconds -

ERXDelayedRequestHandler

public ERXDelayedRequestHandler()

Creates a handler with the default values of 5 second refresh and 5 seconds maxRequestTime. Requests taking longer than 25 seconds are cancelled.

Method Detail

handleRequest

public com.webobjects.appserver.WOResponse handleRequest(com.webobjects.appserver.WORequest request)

Handles the request and returns the applicable response.

Specified by:

handleRequest in class com.webobjects.appserver.WORequestHandler

canHandleRequest

protected boolean canHandleRequest(com.webobjects.appserver.WORequest request)

Returns true if the request handler key can be handled.

Parameters:

request -

handle

protected com.webobjects.appserver.WOResponse handle(com.webobjects.appserver.WORequest request,
                                                     ERXDelayedRequestHandler.DelayedRequest delayedRequest,
                                                     String id)

Override to handle specific actions for the current future.

Parameters:

request -

delayedRequest -

id -

createErrorResponse

protected com.webobjects.appserver.WOResponse createErrorResponse(com.webobjects.appserver.WORequest request)

Create an error page when the future wasn't found anymore. This happens when the user backtracks and it is no longer in the cache. Note that the session has not been awakened.

Parameters:

request - the current request

Returns:

error response

createStoppedResponse

protected com.webobjects.appserver.WOResponse createStoppedResponse(com.webobjects.appserver.WORequest request)

Create a "stopped" page. Note that the session has not been awakened yet and you probably shouldn't do it either. The default implementation redirect to the entry.

Parameters:

request - the request object

Returns:

302 response

cssUrl

protected String cssUrl(com.webobjects.appserver.WORequest request)

createRefreshResponse

protected com.webobjects.appserver.WOResponse createRefreshResponse(com.webobjects.appserver.WORequest request,
                                                                    String url)

Create a refresh page. Note that the session has not been awakened yet and you probably shouldn't do it either.

Parameters:

request - the current request

url - URL to open after refresh

Returns:

refresh page response

refresh

protected int refresh()

Returns the refresh time in seconds for the message page.

Returns:

the refresh time in seconds

maxRequestTimeMillis

protected int maxRequestTimeMillis()

Returns the maximum time in milliseconds for allowed for a request before returning the message page.

Returns:

the maximum request time in milliseconds

activeRequests

public NSArray<ERXDelayedRequestHandler.DelayedRequest> activeRequests()

Returns all active delayed requests.

Returns:

array of delayed requests