org.dellroad.stuff.servlet

Class ExceptionLoggingFilter

java.lang.Object

org.springframework.web.filter.GenericFilterBean

org.springframework.web.filter.OncePerRequestFilter

org.dellroad.stuff.servlet.ExceptionLoggingFilter

All Implemented Interfaces:

Filter, Aware, BeanNameAware, DisposableBean, InitializingBean, EnvironmentAware, EnvironmentCapable, ServletContextAware

public class ExceptionLoggingFilter
extends OncePerRequestFilter

Servlet filter that ensures any exceptions which are not handled by the servlet get logged somewhere.

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 and Description
ExceptionLoggingFilter()

Method Summary

Modifier and Type	Method and Description
void	doFilterInternal(HttpServletRequest request, HttpServletResponse response, FilterChain filterChain) Process the request.
protected Logger	getLogger(HttpServletRequest request, HttpServletResponse response, Throwable t) Get the logging destination.
protected void	logException(HttpServletRequest request, HttpServletResponse response, Throwable t) Log an exception caught by this instance and determined to be loggable by shouldLogException().
protected boolean	shouldLogException(HttpServletRequest request, HttpServletResponse response, Throwable t) Determine if an exception caught by this instance should be logged.

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 Detail

ExceptionLoggingFilter

public ExceptionLoggingFilter()

Method Detail

doFilterInternal

public void doFilterInternal(HttpServletRequest request,
                             HttpServletResponse response,
                             FilterChain filterChain)
                      throws IOException,
                             ServletException

Process the request. If an exception is thrown, it will be (possibly) logged and re-thrown.

Specified by:

doFilterInternal in class OncePerRequestFilter

Throws:

IOException

ServletException

See Also:

shouldLogException()

shouldLogException

protected boolean shouldLogException(HttpServletRequest request,
                                     HttpServletResponse response,
                                     Throwable t)

Determine if an exception caught by this instance should be logged.

The implementation in ExceptionLoggingFilter returns true except for SocketException (typically caused by the client disconnecting) and ThreadDeath (typically caused by virtual machine shutdown). Subclasses should override if necessary.

Parameters:

request - HTTP request

response - HTTP response

t - exception caught by this instance

Returns:

true if exception is loggable

logException

protected void logException(HttpServletRequest request,
                            HttpServletResponse response,
                            Throwable t)

Log an exception caught by this instance and determined to be loggable by shouldLogException().

The implementation in ExceptionLoggingFilter logs the exception as an error via the logger returned by getLogger(). Subclasses should override if necessary.

Parameters:

request - HTTP request

response - HTTP response

t - exception caught by this instance

getLogger

protected Logger getLogger(HttpServletRequest request,
                           HttpServletResponse response,
                           Throwable t)

Get the logging destination.

The implementation in ExceptionLoggingFilter uses the Logger returned by LoggerFactory.getLogger(java.lang.String) when passed this instance's class as the parameter. Subclasses should override if necessary.

Parameters:

request - HTTP request

response - HTTP response

t - the exception about to be logged

Returns:

log destination