atg.filter
Class ConditionalDelegatingFilter

java.lang.Object
  atg.filter.ConditionalDelegatingFilter

All Implemented Interfaces:

javax.servlet.Filter

public class ConditionalDelegatingFilter
extends java.lang.Object
implements javax.servlet.Filter

Invokes another "target" filter if that filter is present in the classpath, or does nothing if the filter is not present. The target filter's init and destroy methods are called from this wrapper's init and destroy methods.

The following snippet from a web.xml file would invoke the com.target.filter filter if it exists. The target filter would have access to its someTargetParameter value.

   <filter>
     <filter-name>MyFilterService</filter-name>
     <filter-class>atg.filter.ConditionalDelegatingFilter</filter-class>
     <init-param>
       <param-name>targetFilter</param-name>
       <param-value>com.target.filter</param-value>
     </init-param>
     <init-param>
       <param-name>someTargetParameter</param-name>
       <param-value>someValue</param-value>
     </init-param>
   </filter>
  

Field Summary

static java.lang.String	CLASS_NAME_PARAMETER_NAME
static java.lang.String	CLASS_VERSION Class version string
static java.lang.String	FILTER_CLASS_NAME
protected javax.servlet.Filter	mTarget

Constructor Summary

ConditionalDelegatingFilter()

Method Summary

void	destroy() Called by the web container to indicate to a filter that it is being taken out of service
void	doFilter(javax.servlet.ServletRequest pRequest, javax.servlet.ServletResponse pResponse, javax.servlet.FilterChain pFilterChain) Called by the web container to indicate that a filter should filter a request/response
void	init(javax.servlet.FilterConfig pFilterConfig) Called by the web container to indicate to a filter that it is being placed into service.

Methods inherited from class java.lang.Object

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

Field Detail

CLASS_VERSION

public static final java.lang.String CLASS_VERSION

Class version string

See Also:

Constant Field Values

FILTER_CLASS_NAME

public static final java.lang.String FILTER_CLASS_NAME

See Also:

Constant Field Values

CLASS_NAME_PARAMETER_NAME

public static final java.lang.String CLASS_NAME_PARAMETER_NAME

See Also:

Constant Field Values

mTarget

protected javax.servlet.Filter mTarget

Constructor Detail

ConditionalDelegatingFilter

public ConditionalDelegatingFilter()

Method Detail

doFilter

public void doFilter(javax.servlet.ServletRequest pRequest,
                     javax.servlet.ServletResponse pResponse,
                     javax.servlet.FilterChain pFilterChain)
              throws java.io.IOException,
                     javax.servlet.ServletException

Called by the web container to indicate that a filter should filter a request/response

Specified by:

doFilter in interface javax.servlet.Filter

Parameters:

pRequest - the servlet request

pServletResponse - the servlet response

pFilterChain - the filter chain

Throws:

java.io.IOException - if an i/o error occurs

javax.servlet.ServletException - if an error occurs when processing this filter

init

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

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

Specified by:

init in interface javax.servlet.Filter

Parameters:

pFilterConfig - filter configuration information

Throws:

javax.servlet.ServletException

destroy

public void destroy()

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

Specified by:

destroy in interface javax.servlet.Filter