Package com.example.blogs.app.logging

Class MdcPopulatingFilter

java.lang.Object

org.springframework.web.filter.GenericFilterBean

org.springframework.web.filter.OncePerRequestFilter

com.example.blogs.app.logging.MdcPopulatingFilter

All Implemented Interfaces:

jakarta.servlet.Filter, Aware, BeanNameAware, DisposableBean, InitializingBean, EnvironmentAware, EnvironmentCapable, ServletContextAware

@Component
@Order(2)
public class MdcPopulatingFilter
extends OncePerRequestFilter

Populates MDC with authenticated user information for request-scoped logging context.

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
MdcPopulatingFilter()

Method Summary

Modifier and Type	Method	Description
protected void	doFilterInternal(jakarta.servlet.http.HttpServletRequest request, jakarta.servlet.http.HttpServletResponse response, jakarta.servlet.FilterChain filterChain)	Extracts authenticated user ID from security context and populates MDC for use in log messages.

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

MdcPopulatingFilter

public MdcPopulatingFilter()

Method Details

doFilterInternal

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

Extracts authenticated user ID from security context and populates MDC for use in log messages. Runs after authentication is established but before business logic executes.

Specified by:

doFilterInternal in class OncePerRequestFilter

Parameters:

request - the HTTP request

response - the HTTP response

filterChain - the filter chain to continue processing

Throws:

jakarta.servlet.ServletException - if request processing fails

IOException - if an I/O error occurs during filtering