org.springframework.web.struts
Class AutowiringRequestProcessor

java.lang.Object
  org.apache.struts.action.RequestProcessor
      org.springframework.web.struts.AutowiringRequestProcessor

public class AutowiringRequestProcessor
extends RequestProcessor

Subclass of Struts's default RequestProcessor that autowires Struts Actions with Spring beans defined in ContextLoaderPlugIn's WebApplicationContext or - in case of general service layer beans - in the root WebApplicationContext.

In the Struts config file, you simply continue to specify the original Action class. The instance created for that class will automatically get wired with matching service layer beans, that is, bean property setters will automatically be called if a service layer bean matches the property.

 <action path="/login" type="myapp.MyAction"/>

There are two autowire modes available: "byType" and "byName". The default is "byType", matching service layer beans with the Action's bean property argument types. This behavior can be changed through specifying an "autowire" init-param for the Struts ActionServlet with the value "byName", which will match service layer bean names with the Action's bean property names.

Dependency checking is turned off by default: If no matching service layer bean can be found, the setter in question will simply not get invoked. To enforce matching service layer beans, consider specify the "dependencyCheck" init-param for the Struts ActionServlet with the value "true".

If you also need the Tiles setup functionality of the original TilesRequestProcessor, use AutowiringTilesRequestProcessor. As there's just a single central class to customize in Struts, we have to provide another subclass here, covering both the Tiles and the Spring delegation aspect.

The default implementation delegates to the DelegatingActionUtils class as fas as possible, to reuse as much code as possible despite the need to provide two RequestProcessor subclasses. If you need to subclass yet another RequestProcessor, take this class as a template, delegating to DelegatingActionUtils just like it.

Since:

2.0

Author:

Juergen Hoeller

See Also:

AutowiringTilesRequestProcessor, ContextLoaderPlugIn, DelegatingActionUtils

Field Summary

Fields inherited from class org.apache.struts.action.RequestProcessor

actions, INCLUDE_PATH_INFO, INCLUDE_SERVLET_PATH, log, moduleConfig, servlet

Constructor Summary

AutowiringRequestProcessor()

Method Summary

protected int	getAutowireMode() Return the autowire mode to use for wiring Struts Actions.
protected boolean	getDependencyCheck() Return whether to apply a dependency check after wiring Struts Actions.
protected WebApplicationContext	getWebApplicationContext() Return the current Spring WebApplicationContext.
void	init(ActionServlet actionServlet, ModuleConfig moduleConfig)
protected int	initAutowireMode(ActionServlet actionServlet, ModuleConfig moduleConfig) Determine the autowire mode to use for wiring Struts Actions.
protected boolean	initDependencyCheck(ActionServlet actionServlet, ModuleConfig moduleConfig) Determine whether to apply a dependency check after wiring Struts Actions.
protected WebApplicationContext	initWebApplicationContext(ActionServlet actionServlet, ModuleConfig moduleConfig) Fetch ContextLoaderPlugIn's WebApplicationContext from the ServletContext, falling back to the root WebApplicationContext.
protected Action	processActionCreate(HttpServletRequest request, HttpServletResponse response, ActionMapping mapping) Extend the base class method to autowire each created Action instance.

Methods inherited from class org.apache.struts.action.RequestProcessor

destroy, doForward, doInclude, getInternal, getServletContext, internalModuleRelativeForward, internalModuleRelativeInclude, log, log, process, processActionForm, processActionPerform, processCachedMessages, processContent, processException, processForward, processForwardConfig, processInclude, processLocale, processMapping, processMultipart, processNoCache, processPath, processPopulate, processPreprocess, processRoles, processValidate

Methods inherited from class java.lang.Object

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

Constructor Detail

AutowiringRequestProcessor

public AutowiringRequestProcessor()

Method Detail

init

public void init(ActionServlet actionServlet,
                 ModuleConfig moduleConfig)
          throws ServletException

Overrides:

init in class RequestProcessor

Throws:

ServletException

initWebApplicationContext

protected WebApplicationContext initWebApplicationContext(ActionServlet actionServlet,
                                                          ModuleConfig moduleConfig)
                                                   throws IllegalStateException

Fetch ContextLoaderPlugIn's WebApplicationContext from the ServletContext, falling back to the root WebApplicationContext. This context is supposed to contain the service layer beans to wire the Struts Actions with.

Parameters:

actionServlet - the associated ActionServlet

moduleConfig - the associated ModuleConfig

Returns:

the WebApplicationContext

Throws:

IllegalStateException - if no WebApplicationContext could be found

See Also:

DelegatingActionUtils.findRequiredWebApplicationContext(org.apache.struts.action.ActionServlet, org.apache.struts.config.ModuleConfig), ContextLoaderPlugIn.SERVLET_CONTEXT_PREFIX

initAutowireMode

protected int initAutowireMode(ActionServlet actionServlet,
                               ModuleConfig moduleConfig)

Determine the autowire mode to use for wiring Struts Actions.

The default implementation checks the "autowire" init-param of the Struts ActionServlet, falling back to "AUTOWIRE_BY_TYPE" as default.

Parameters:

actionServlet - the associated ActionServlet

moduleConfig - the associated ModuleConfig

Returns:

the autowire mode to use

See Also:

DelegatingActionUtils.getAutowireMode(org.apache.struts.action.ActionServlet), AutowireCapableBeanFactory.autowireBeanProperties(java.lang.Object, int, boolean), AutowireCapableBeanFactory.AUTOWIRE_BY_TYPE, AutowireCapableBeanFactory.AUTOWIRE_BY_NAME

initDependencyCheck

protected boolean initDependencyCheck(ActionServlet actionServlet,
                                      ModuleConfig moduleConfig)

Determine whether to apply a dependency check after wiring Struts Actions.

The default implementation checks the "dependencyCheck" init-param of the Struts ActionServlet, falling back to no dependency check as default.

Parameters:

actionServlet - the associated ActionServlet

moduleConfig - the associated ModuleConfig

Returns:

whether to enforce a dependency check or not

See Also:

DelegatingActionUtils.getDependencyCheck(org.apache.struts.action.ActionServlet), AutowireCapableBeanFactory.autowireBeanProperties(java.lang.Object, int, boolean)

getWebApplicationContext

protected final WebApplicationContext getWebApplicationContext()

Return the current Spring WebApplicationContext.

getAutowireMode

protected final int getAutowireMode()

Return the autowire mode to use for wiring Struts Actions.

getDependencyCheck

protected final boolean getDependencyCheck()

Return whether to apply a dependency check after wiring Struts Actions.

processActionCreate

protected Action processActionCreate(HttpServletRequest request,
                                     HttpServletResponse response,
                                     ActionMapping mapping)
                              throws IOException

Extend the base class method to autowire each created Action instance.

Overrides:

processActionCreate in class RequestProcessor

Throws:

IOException

See Also:

AutowireCapableBeanFactory.autowireBeanProperties(java.lang.Object, int, boolean)