public Class MDCInsertingServletFilter

Overrides default jakarta.servlet.Filter.destroy.

Doc from jakarta.servlet.Filter.destroy.

Called by the web container to indicate to a filter that it is being taken out of service.

This method is only called once all threads within the filter's doFilter method have exited or after a timeout period has passed. After the web container calls this method, it will not call the doFilter method again on this instance of the filter.

This method gives the filter an opportunity to clean up any resources that are being held (for example, memory, file handles, threads) and make sure that any persistent state is synchronized with the filter's current state in memory.

Implements jakarta.servlet.Filter.doFilter.

Doc from jakarta.servlet.Filter.doFilter.

The doFilter method of the Filter is called by the container each time a request/response pair is passed through the chain due to a client request for a resource at the end of the chain. The FilterChain passed in to this method allows the Filter to pass on the request and response to the next entity in the chain.

A typical implementation of this method would follow the following pattern:

1. Examine the request
2. Optionally wrap the request object with a custom implementation to filter content or headers for input filtering
3. Optionally wrap the response object with a custom implementation to filter content or headers for output filtering
4. • Either invoke the next entity in the chain using the FilterChain object (chain.doFilter()),
   • or not pass on the request/response pair to the next entity in the filter chain to block the request processing
5. Directly set headers on the response after invocation of the next entity in the filter chain.

Parameters

request:ServletRequest

the ServletRequest object contains the client's request

response:ServletResponse

the ServletResponse object contains the filter's response

chain:FilterChain

the FilterChain for invoking the next filter or the resource

Exceptions

IOException:

if an I/O related error has occurred during the processing

ServletException:

if an exception occurs that interferes with the filter's normal operation

Overrides default jakarta.servlet.Filter.init.

Doc from jakarta.servlet.Filter.init.

Called by the web container to indicate to a filter that it is being placed into service.

The servlet container calls the init method exactly once after instantiating the filter. The init method must complete successfully before the filter is asked to do any filtering work. The container will ensure that actions performed in the init method will be visible to any threads that subsequently call the doFilter method according to the rules in JSR-133 (i.e. there is a 'happens before' relationship between init and doFilter).

The web container cannot place the filter into service if the init method either

1. Throws a ServletException
2. Does not return within a time period defined by the web container

Parameters

arg0:FilterConfig

a FilterConfig object containing the filter's configuration and initialization parameters

Exceptions

ServletException:

if an exception has occurred that interferes with the filter's normal operation