org.apache.catalina.filters
Class FilterBase

java.lang.Object
  org.apache.catalina.filters.FilterBase

All Implemented Interfaces:

javax.servlet.Filter

Direct Known Subclasses:

CsrfPreventionFilter, FailedRequestFilter, SetCharacterEncodingFilter

public abstract class FilterBase
extends java.lang.Object
implements javax.servlet.Filter

Base class for filters that provides generic initialisation and a simple no-op destruction.

Author:

xxd

sm

protected static final StringManager sm

FilterBase

public FilterBase()

getLogger

protected abstract Log getLogger()

init

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

Description copied from interface: javax.servlet.Filter

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 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

Specified by:

init in interface javax.servlet.Filter

Throws:

javax.servlet.ServletException

destroy

public void destroy()

Description copied from interface: javax.servlet.Filter

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.

Specified by:

destroy in interface javax.servlet.Filter

isConfigProblemFatal

protected boolean isConfigProblemFatal()

Determines if an exception when calling a setter or an unknown configuration attribute triggers the failure of the this filter which in turn will prevent the web application from starting.

Returns:

true if a problem should trigger the failure of this filter, else false