rwinch / onceperrequest-error-dispatch

Problem

Note	This was reported via spring-projects/spring-framework#22989 and spring-projects/spring-session#1308

It appears that instances of OncePerRequestFilter do not get invoked for error dispatch types on Jetty even when the following conditions are true:

• The Filter is configured to dispatch on error dispatch types

• The Filter returns false for shouldNotFilterErrorDispatch

Sample

I created a simple application that demonstrates the issue.

• RequestWrapperFilter

  • Is an instance of OncePerRequestFilter which returns false for shouldNotFilterErrorDispatch

  • Wraps the HttpServletRequest with a dummy RequestWrapper

• IndexController

  • processes / and /error

  • sets a model attribute for isWrapped based on if the HttpServletRequest is wrapped by RequestWrapper

Jetty

You can run on Jetty using the jetty profile (default). On Jetty the sample works for request dispatch (i.e. http://localhost:8080/) and fails for error dispatch (i.e. http://localhost:8080/notfound)

A few observations:

• RequestWrapperFilter is invoked the first time and it wraps the request (expected)

• RequestWrapperFilter is not invoked on the error dispatch because the hasAlreadyFilteredAttribute is true (surprising)

• RequestWrapperFilter finally block which clears the attributes is not invoked until after the controller is invoked (surprising)

Tomcat

You can run on Tomcat by ensuring the tomcat profile is active and jetty profile is off. On Tomcat the sample works for both request dispatch (i.e. http://localhost:8080/) and error dispatch (i.e. http://localhost:8080/notfound)

A few observations:

• RequestWrapperFilter is invoked the first time and it wraps the request

• RequestWrapperFilter is invoked on the error dispatch because the hasAlreadyFilteredAttribute is true

• RequestWrapperFilter finally block which clears the attributes is invoked before the controller is invoked

Tests

To see the failures run the tests with the jetty profile (default). You will observe that the test for a page that is not found fails.

./mvnw test

Rerun the tests using tomcat profile and the tests pass.

./mvnw test -Ptomcat