Package org.apache.hadoop.lib.servlet

Class MDCFilter

java.lang.Object

org.apache.hadoop.lib.servlet.MDCFilter

All Implemented Interfaces:

javax.servlet.Filter

@Private
public class MDCFilter
extends Object
implements javax.servlet.Filter

Filter that sets request contextual information for the slf4j MDC.

It sets the following values:

• hostname: if the HostnameFilter is present and configured before this filter
• user: the HttpServletRequest.getUserPrincipal().getName()
• method: the HTTP method fo the request (GET, POST, ...)
• path: the path of the request URL

Constructor Summary

Constructors

Constructor	Description
MDCFilter()

Method Summary

Modifier and Type	Method	Description
void	destroy()	Destroys the filter.
void	doFilter(javax.servlet.ServletRequest request, javax.servlet.ServletResponse response, javax.servlet.FilterChain chain)	Sets the slf4j MDC and delegates the request to the chain.
void	init(javax.servlet.FilterConfig config)	Initializes the filter.

Methods inherited from class java.lang.Object

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

Constructor Details

MDCFilter

public MDCFilter()

Method Details

init

public void init(javax.servlet.FilterConfig config)
          throws javax.servlet.ServletException

Initializes the filter.

This implementation is a NOP.

Specified by:

init in interface javax.servlet.Filter

Parameters:

config - filter configuration.

Throws:

javax.servlet.ServletException - thrown if the filter could not be initialized.

doFilter

public void doFilter(javax.servlet.ServletRequest request,
 javax.servlet.ServletResponse response,
 javax.servlet.FilterChain chain)
              throws IOException,
javax.servlet.ServletException

Sets the slf4j MDC and delegates the request to the chain.

Specified by:

doFilter in interface javax.servlet.Filter

Parameters:

request - servlet request.

response - servlet response.

chain - filter chain.

Throws:

IOException - thrown if an IO error occurs.

javax.servlet.ServletException - thrown if a servlet error occurs.

destroy

public void destroy()

Destroys the filter.

This implementation is a NOP.

Specified by:

destroy in interface javax.servlet.Filter