org.apache.shiro.web.servlet
Class OncePerRequestFilter

java.lang.Object
  org.apache.shiro.web.servlet.ServletContextSupport
      org.apache.shiro.web.servlet.AbstractFilter
          org.apache.shiro.web.servlet.NameableFilter
              org.apache.shiro.web.servlet.OncePerRequestFilter

All Implemented Interfaces:

Filter, Nameable

Direct Known Subclasses:

AbstractShiroFilter, AdviceFilter

public abstract class OncePerRequestFilter
extends NameableFilter

Filter base class that guarantees to be just executed once per request, on any servlet container. It provides a doFilterInternal(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain) method with HttpServletRequest and HttpServletResponse arguments.

The getAlreadyFilteredAttributeName() method determines how to identify that a request is already filtered. The default implementation is based on the configured name of the concrete filter instance.

NOTE This class was borrowed from the Spring framework, and as such, all copyright notices and author names have remained in tact.

Since:

0.1

Field Summary

static String

ALREADY_FILTERED_SUFFIX Suffix that gets appended to the filter name for the "already filtered" request attribute.

Fields inherited from class org.apache.shiro.web.servlet.AbstractFilter

filterConfig

Constructor Summary

OncePerRequestFilter()

Method Summary

void	doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) This doFilter implementation stores a request attribute for "already filtered", proceeding without filtering again if the attribute is already there.
protected abstract void	doFilterInternal(ServletRequest request, ServletResponse response, FilterChain chain) Same contract as for doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain), but guaranteed to be invoked only once per request.
protected String	getAlreadyFilteredAttributeName() Return name of the request attribute that identifies that a request has already been filtered.
protected boolean	shouldNotFilter(ServletRequest request) Can be overridden in subclasses for custom filtering control, returning true to avoid filtering of the given request.

Methods inherited from class org.apache.shiro.web.servlet.NameableFilter

getName, setName, toStringBuilder

Methods inherited from class org.apache.shiro.web.servlet.AbstractFilter

destroy, getFilterConfig, getInitParam, init, onFilterConfigSet, setFilterConfig

Methods inherited from class org.apache.shiro.web.servlet.ServletContextSupport

getContextAttribute, getContextInitParam, getServletContext, removeContextAttribute, setContextAttribute, setServletContext, toString

Methods inherited from class java.lang.Object

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

Field Detail

ALREADY_FILTERED_SUFFIX

public static final String ALREADY_FILTERED_SUFFIX

Suffix that gets appended to the filter name for the "already filtered" request attribute.

See Also:

getAlreadyFilteredAttributeName(), Constant Field Values

Constructor Detail

OncePerRequestFilter

public OncePerRequestFilter()

Method Detail

doFilter

public final void doFilter(ServletRequest request,
                           ServletResponse response,
                           FilterChain filterChain)
                    throws ServletException,
                           IOException

This doFilter implementation stores a request attribute for "already filtered", proceeding without filtering again if the attribute is already there.

Throws:

ServletException

IOException

See Also:

getAlreadyFilteredAttributeName(), shouldNotFilter(javax.servlet.ServletRequest), doFilterInternal(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)

getAlreadyFilteredAttributeName

protected String getAlreadyFilteredAttributeName()

Return name of the request attribute that identifies that a request has already been filtered.

The default implementation takes the configured name and appends ".FILTERED". If the filter is not fully initialized, it falls back to the implementation's class name.

Returns:

the name of the request attribute that identifies that a request has already been filtered.

See Also:

NameableFilter.getName(), ALREADY_FILTERED_SUFFIX

shouldNotFilter

protected boolean shouldNotFilter(ServletRequest request)
                           throws ServletException

Can be overridden in subclasses for custom filtering control, returning true to avoid filtering of the given request.

The default implementation always returns false.

Parameters:

request - current HTTP request

Returns:

whether the given request should not be filtered

Throws:

ServletException - in case of errors

doFilterInternal

protected abstract void doFilterInternal(ServletRequest request,
                                         ServletResponse response,
                                         FilterChain chain)
                                  throws ServletException,
                                         IOException

Same contract as for doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain), but guaranteed to be invoked only once per request.

Parameters:

request - incoming ServletRequest

response - outgoing ServletResponse

chain - the FilterChain to execute

Throws:

ServletException - if there is a problem processing the request

IOException - if there is an I/O problem processing the request