org.apache.struts2.dispatcher
Class FilterDispatcher

java.lang.Object
  org.apache.struts2.dispatcher.FilterDispatcher

All Implemented Interfaces:

javax.servlet.Filter, StrutsStatics

Direct Known Subclasses:

FilterDispatcherCompatWeblogic61

Deprecated. Since Struts 2.1.3, use StrutsPrepareAndExecuteFilter instead or StrutsPrepareFilter and StrutsExecuteFilter if needing using the ActionContextCleanUp filter in addition to this one

public class FilterDispatcher
extends Object
implements StrutsStatics, javax.servlet.Filter

Master filter for Struts that handles four distinct responsibilities:

• Executing actions
• Cleaning up the ActionContext (see note)
• Serving static content
• Kicking off XWork's interceptor chain for the request lifecycle

IMPORTANT: this filter must be mapped to all requests. Unless you know exactly what you are doing, always map to this URL pattern: /*

Executing actions

This filter executes actions by consulting the ActionMapper and determining if the requested URL should invoke an action. If the mapper indicates it should, the rest of the filter chain is stopped and the action is invoked. This is important, as it means that filters like the SiteMesh filter must be placed before this filter or they will not be able to decorate the output of actions.

Cleaning up the ActionContext

This filter will also automatically clean up the ActionContext for you, ensuring that no memory leaks take place. However, this can sometimes cause problems integrating with other products like SiteMesh. See ActionContextCleanUp for more information on how to deal with this.

Serving static content

This filter also serves common static content needed when using various parts of Struts, such as JavaScript files, CSS files, etc. It works by looking for requests to /struts/*, and then mapping the value after "/struts/" to common packages in Struts and, optionally, in your class path. By default, the following packages are automatically searched:

• org.apache.struts2.static
• template

This means that you can simply request /struts/xhtml/styles.css and the XHTML UI theme's default stylesheet will be returned. Likewise, many of the AJAX UI components require various JavaScript files, which are found in the org.apache.struts2.static package. If you wish to add additional packages to be searched, you can add a comma separated (space, tab and new line will do as well) list in the filter init parameter named "packages". Be careful, however, to expose any packages that may have sensitive information, such as properties file with database access credentials.

This filter supports the following init-params:

• config - a comma-delimited list of XML configuration files to load.
• actionPackages - a comma-delimited list of Java packages to scan for Actions.
• configProviders - a comma-delimited list of Java classes that implement the ConfigurationProvider interface that should be used for building the Configuration.
• loggerFactory - The class name of the LoggerFactory implementation.
• * - any other parameters are treated as framework constants.

To use a custom Dispatcher, the createDispatcher() method could be overriden by the subclass.

Version:

$Date$ $Id$

See Also:

ActionMapper, ActionContextCleanUp, StrutsPrepareAndExecuteFilter, StrutsPrepareFilter, StrutsExecuteFilter

Field Summary

protected Dispatcher	dispatcher Deprecated. Expose Dispatcher instance to subclass.
protected StaticContentLoader	staticResourceLoader Deprecated. Loads static resources, set by injection.

Fields inherited from interface org.apache.struts2.StrutsStatics

HTTP_REQUEST, HTTP_RESPONSE, PAGE_CONTEXT, SERVLET_CONTEXT, SERVLET_DISPATCHER, STRUTS_ACTION_TAG_INVOCATION, STRUTS_PORTLET_CONTEXT

Constructor Summary

FilterDispatcher()
Deprecated.

Method Summary

protected Dispatcher	createDispatcher(javax.servlet.FilterConfig filterConfig) Deprecated. Create a default Dispatcher that subclasses can override with a custom Dispatcher, if needed.
protected Dispatcher	createDispatcher(javax.servlet.ServletContext ctx, Map<String,String> params) Deprecated. Create a default Dispatcher that subclasses can override with a custom Dispatcher, if needed.
void	destroy() Deprecated. Calls dispatcher.cleanup, which in turn releases local threads and destroys any DispatchListeners.
void	doFilter(javax.servlet.ServletRequest req, javax.servlet.ServletResponse res, javax.servlet.FilterChain chain) Deprecated. Process an action or handle a request a static resource.
static Boolean	getDevModeOverride() Deprecated.
protected javax.servlet.FilterConfig	getFilterConfig() Deprecated. Expose the FilterConfig instance.
protected javax.servlet.ServletContext	getServletContext() Deprecated. Provide a workaround for some versions of WebLogic.
void	init(javax.servlet.FilterConfig filterConfig) Deprecated. Initializes the filter by creating a default dispatcher and setting the default packages for static resources.
static void	overrideDevMode(boolean devMode) Deprecated. Set an override of the static devMode value.
protected javax.servlet.http.HttpServletRequest	prepareDispatcherAndWrapRequest(javax.servlet.http.HttpServletRequest request, javax.servlet.http.HttpServletResponse response) Deprecated. Wrap and return the given request, if needed, so as to to transparently handle multipart data as a wrapped class around the given request.
void	setActionMapper(ActionMapper mapper) Deprecated. Modify ActionMapper instance.
void	setStaticResourceLoader(StaticContentLoader staticResourceLoader) Deprecated. Modify state of StrutsConstants.STRUTS_STATIC_CONTENT_LOADER setting.

Methods inherited from class java.lang.Object

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

Field Detail

dispatcher

protected Dispatcher dispatcher

Deprecated.

Expose Dispatcher instance to subclass.

staticResourceLoader

protected StaticContentLoader staticResourceLoader

Deprecated.

Loads static resources, set by injection.

Constructor Detail

FilterDispatcher

public FilterDispatcher()

Deprecated.

Method Detail

init

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

Deprecated.

Initializes the filter by creating a default dispatcher and setting the default packages for static resources.

Specified by:

init in interface javax.servlet.Filter

Parameters:

filterConfig - The filter configuration

Throws:

javax.servlet.ServletException

destroy

public void destroy()

Deprecated.

Calls dispatcher.cleanup, which in turn releases local threads and destroys any DispatchListeners.

Specified by:

destroy in interface javax.servlet.Filter

See Also:

Filter.destroy()

overrideDevMode

public static void overrideDevMode(boolean devMode)

Deprecated.

Set an override of the static devMode value. Do not set this via a request parameter or any other unprotected method. Using a signed cookie is one safe way to turn it on per request.

Parameters:

devMode - the override value

getDevModeOverride

public static Boolean getDevModeOverride()

Deprecated.

Returns:

Boolean override value, or null if no override

createDispatcher

protected Dispatcher createDispatcher(javax.servlet.FilterConfig filterConfig)

Deprecated.

Create a default Dispatcher that subclasses can override with a custom Dispatcher, if needed.

Parameters:

filterConfig - Our FilterConfig

Returns:

Initialized Dispatcher

createDispatcher

protected Dispatcher createDispatcher(javax.servlet.ServletContext ctx,
                                      Map<String,String> params)

Deprecated.

Create a default Dispatcher that subclasses can override with a custom Dispatcher, if needed. Called by createDispatcher(FilterConfig).

Parameters:

ctx - ServletContext

params - parameters from FilterConfig

Returns:

Initialized Dispatcher

setStaticResourceLoader

public void setStaticResourceLoader(StaticContentLoader staticResourceLoader)

Deprecated.

Modify state of StrutsConstants.STRUTS_STATIC_CONTENT_LOADER setting.

Parameters:

staticResourceLoader - val New setting

setActionMapper

public void setActionMapper(ActionMapper mapper)

Deprecated.

Modify ActionMapper instance.

Parameters:

mapper - New instance

getServletContext

protected javax.servlet.ServletContext getServletContext()

Deprecated.

Provide a workaround for some versions of WebLogic.

Servlet 2.3 specifies that the servlet context can be retrieved from the session. Unfortunately, some versions of WebLogic can only retrieve the servlet context from the filter config. Hence, this method enables subclasses to retrieve the servlet context from other sources.

Returns:

the servlet context.

getFilterConfig

protected javax.servlet.FilterConfig getFilterConfig()

Deprecated.

Expose the FilterConfig instance.

Returns:

Our FilterConfit instance

prepareDispatcherAndWrapRequest

protected javax.servlet.http.HttpServletRequest prepareDispatcherAndWrapRequest(javax.servlet.http.HttpServletRequest request,
                                                                                javax.servlet.http.HttpServletResponse response)
                                                                         throws javax.servlet.ServletException

Deprecated.

Wrap and return the given request, if needed, so as to to transparently handle multipart data as a wrapped class around the given request.

Parameters:

request - Our ServletRequest object

response - Our ServerResponse object

Returns:

Wrapped HttpServletRequest object

Throws:

javax.servlet.ServletException - on any error

doFilter

public void doFilter(javax.servlet.ServletRequest req,
                     javax.servlet.ServletResponse res,
                     javax.servlet.FilterChain chain)
              throws IOException,
                     javax.servlet.ServletException

Deprecated.

Process an action or handle a request a static resource.

The filter tries to match the request to an action mapping. If mapping is found, the action processes is delegated to the dispatcher's serviceAction method. If action processing fails, doFilter will try to create an error page via the dispatcher.

Otherwise, if the request is for a static resource, the resource is copied directly to the response, with the appropriate caching headers set.

If the request does not match an action mapping, or a static resource page, then it passes through.

Specified by:

doFilter in interface javax.servlet.Filter

Throws:

IOException

javax.servlet.ServletException

See Also:

Filter.doFilter(javax.servlet.ServletRequest, javax.servlet.ServletResponse, javax.servlet.FilterChain)