Package com.vaadin.observability.spring

Class SpringResyncDetectionFilter

java.lang.Object

org.springframework.web.filter.GenericFilterBean

org.springframework.web.filter.OncePerRequestFilter

com.vaadin.observability.spring.SpringResyncDetectionFilter

All Implemented Interfaces:

jakarta.servlet.Filter, org.springframework.beans.factory.Aware, org.springframework.beans.factory.BeanNameAware, org.springframework.beans.factory.DisposableBean, org.springframework.beans.factory.InitializingBean, org.springframework.context.EnvironmentAware, org.springframework.core.env.EnvironmentCapable, org.springframework.web.context.ServletContextAware

public final class SpringResyncDetectionFilter
extends org.springframework.web.filter.OncePerRequestFilter

Spring-optimized servlet filter that observes UIDL message resends and resynchronization requests (prototype, kit-only, no Flow changes). Shares its detection logic with the portable ResyncDetectionFilter via ResyncInspector, but is preferred wherever Spring is on the classpath.

Flow recovers from lost responses entirely inside UidlRequestHandler by catching ClientResentPayloadException (replay the cached response) and ResynchronizationRequiredException (rebuild the UI state); neither surfaces to any Flow listener SPI the kit uses.

Rather than buffer the body eagerly, this filter wraps the request in a ContentCachingRequestWrapper and inspects after the chain has run: ordering is irrelevant for a counter, and this way we read exactly the bytes Flow read and only count requests Flow actually consumed. The per-UI read-modify-write is guarded by the session mutex. Instrumentation never fails the request: any error while inspecting is swallowed.

Field Summary

Fields inherited from class org.springframework.web.filter.OncePerRequestFilter

ALREADY_FILTERED_SUFFIX

Fields inherited from class org.springframework.web.filter.GenericFilterBean

logger

Constructor Summary

Constructors

Constructor	Description
SpringResyncDetectionFilter(io.micrometer.core.instrument.MeterRegistry registry)	Creates the filter recording into the given registry.

Method Summary

Modifier and Type	Method	Description
protected void	doFilterInternal(jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response, jakarta.servlet.FilterChain chain)

Methods inherited from class org.springframework.web.filter.OncePerRequestFilter

doFilter, doFilterNestedErrorDispatch, getAlreadyFilteredAttributeName, isAsyncDispatch, isAsyncStarted, shouldNotFilter, shouldNotFilterAsyncDispatch, shouldNotFilterErrorDispatch

Methods inherited from class org.springframework.web.filter.GenericFilterBean

addRequiredProperty, afterPropertiesSet, createEnvironment, destroy, getEnvironment, getFilterConfig, getFilterName, getServletContext, init, initBeanWrapper, initFilterBean, setBeanName, setEnvironment, setServletContext

Methods inherited from class java.lang.Object

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

Constructor Details

SpringResyncDetectionFilter

public SpringResyncDetectionFilter(io.micrometer.core.instrument.MeterRegistry registry)

Creates the filter recording into the given registry.

Parameters:

registry - the meter registry, not null

Method Details

doFilterInternal

protected void doFilterInternal(jakarta.servlet.http.HttpServletRequest request,
 jakarta.servlet.http.HttpServletResponse response,
 jakarta.servlet.FilterChain chain)
                         throws jakarta.servlet.ServletException,
IOException

Specified by:

doFilterInternal in class org.springframework.web.filter.OncePerRequestFilter

Throws:

jakarta.servlet.ServletException

IOException