Package org.apache.shiro.web.servlet

Class AbstractFilter

java.lang.Object

org.apache.shiro.web.servlet.ServletContextSupport

org.apache.shiro.web.servlet.AbstractFilter

All Implemented Interfaces:

javax.servlet.Filter

Direct Known Subclasses:

NameableFilter

public abstract class AbstractFilter
extends ServletContextSupport
implements javax.servlet.Filter

Base abstract Filter simplifying Filter initialization and access to init parameters. Subclass initialization logic should be performed by overriding the onFilterConfigSet() template method. FilterChain execution logic (the Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain) method is left to subclasses.

Since:

1.0

Field Summary

Fields

Modifier and Type	Field	Description
protected javax.servlet.FilterConfig	filterConfig	FilterConfig provided by the Servlet container at start-up.

Constructor Summary

Constructors

Constructor	Description
AbstractFilter()

Method Summary

Modifier and Type	Method	Description
void	destroy()	Default no-op implementation that can be overridden by subclasses for custom cleanup behavior.
javax.servlet.FilterConfig	getFilterConfig()	Returns the servlet container specified FilterConfig instance provided at startup.
protected String	getInitParam(String paramName)	Returns the value for the named init-param, or null if there was no init-param specified by that name.
final void	init(javax.servlet.FilterConfig filterConfig)	Sets the filter's filterConfig and then immediately calls onFilterConfigSet() to trigger any processing a subclass might wish to perform.
protected void	onFilterConfigSet()	Template method to be overridden by subclasses to perform initialization logic at start-up.
void	setFilterConfig(javax.servlet.FilterConfig filterConfig)	Sets the FilterConfig and the ServletContext as attributes of this class for use by subclasses.

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

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

Methods inherited from class java.lang.Object

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

Methods inherited from interface javax.servlet.Filter

doFilter

Field Details

filterConfig

protected javax.servlet.FilterConfig filterConfig

FilterConfig provided by the Servlet container at start-up.

Constructor Details

AbstractFilter

public AbstractFilter()

Method Details

getFilterConfig

public javax.servlet.FilterConfig getFilterConfig()

Returns the servlet container specified FilterConfig instance provided at startup.

Returns:

the servlet container specified FilterConfig instance provided at start-up.

setFilterConfig

public void setFilterConfig(javax.servlet.FilterConfig filterConfig)

Sets the FilterConfig and the ServletContext as attributes of this class for use by subclasses. That is:

 this.filterConfig = filterConfig;
 setServletContext(filterConfig.getServletContext());

Parameters:

filterConfig - the FilterConfig instance provided by the Servlet container at start-up.

getInitParam

protected String getInitParam(String paramName)

Returns the value for the named init-param, or null if there was no init-param specified by that name.

Parameters:

paramName - the name of the init-param

Returns:

the value for the named init-param, or null if there was no init-param specified by that name.

init

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

Sets the filter's filterConfig and then immediately calls onFilterConfigSet() to trigger any processing a subclass might wish to perform.

Specified by:

init in interface javax.servlet.Filter

Parameters:

filterConfig - the servlet container supplied FilterConfig instance.

Throws:

javax.servlet.ServletException - if onFilterConfigSet() throws an Exception.

onFilterConfigSet

protected void onFilterConfigSet()
                          throws Exception

Template method to be overridden by subclasses to perform initialization logic at start-up. The ServletContext and FilterConfig will be accessible (and non-null) at the time this method is invoked via the getServletContext() and getFilterConfig() methods respectively.

init-param values may be conveniently obtained via the getInitParam(String) method.

Throws:

Exception - if the subclass has an error upon initialization.

destroy

public void destroy()

Default no-op implementation that can be overridden by subclasses for custom cleanup behavior.

Specified by:

destroy in interface javax.servlet.Filter