com.boylesoftware.cb2.presentation.servlet
Class CB2PlugIn

java.lang.Object
  com.boylesoftware.cb2.presentation.servlet.CB2PlugIn

All Implemented Interfaces:

org.apache.struts.action.PlugIn

public final class CB2PlugIn

extends java.lang.Object

implements org.apache.struts.action.PlugIn

Struts plugin to enable CB2 presentation level for a Struts module. This plugin should be set up for each module that uses CB2. Regardless of how any instances of the plugin you install for different modules they all will share the same application context, business logic level and other basic application-wide subsystems, however each module will have its own presentation level subsystems such as CB2 pages.

The plugin expects the following init parameters:

• pages-config - web-application context relative URL of the pages definition file. If not specified defaults to /WEB-INF/pages-config.xml.
• controller - name of the controller class. The controller class should extend com.boylesoftware.cb2.presentation.servlet.CB2RequestProcessor. If not specified defaults to CB2RequestProcessor.
• uistate - name of the UI state bean class. The class must extend com.boylesoftware.cb2.presentation.servlet.UIState. If not specified the module will be provided with the default UIState implementation.
• lockedUrl - URL of a page that should be displayed when a request comes to the module while the application is locked via the admin interface. If it is not specified the system sends a Service Unavailable error code in response to the request.
• requestCharEncoding
- character encoding for requests. If specified, CB2 will explicitely set it on every request using ServletRequest.setCharacterEncoding method before passing control to any action or page.
• responseContentType
- response content type string (optionally with encoding). If specified, CB2 will explicitely set it on every response using ServletResponse.setContentType, as well as set HTTP header "Content-Type" using HttpServletResponse.setHeader. The difference of this mechanism from Struts' controller "contentType" attribute is that Struts only calls setContentType and does not explicitely sets the "Content-Type" HTTP response header, which may be required in some Servlet Container implementations for proper results. As in Struts, CB2 sets the content type before passing control to any action or page, which, if desired, may override it. Note, that if this parameter is specified, the framework sets content type on every response. More often it is better to control this on per page basis via "contentType" attribute of <page> elements in the PL configuration file, and since "contentType" attribute is inheritable, you can achieve the same effect by specifying it for an abstract page, which is extended by all other pages.

Below is a sample fragment of a struts config file:

 ...
 <plug-in className="com.boylesoftware.cb2.presentation.servlet.CB2PlugIn">
   <set-property
     property="pages-config"
     value="/WEB-INF/pages-config-mymodule.xml"/>
   <set-property
     property="uistate"
     value="my.package.MyUIState"/>
 </plug-in>
 ...
 

Note that this plugin installs its own implementation of the RequestProcessor for the module and therefore it is not compatible with other plugins that do the same, for example with TilesPlugin.

This implementation supports persistent sessions provided that you set com.boylesoftware.cb2.keepBLSessions application property to true so the BLManager does not destroy BLO containers when the application goes down. Note that if you turn on persistent sessions in your servlet container implementation and forget to set the com.boylesoftware.cb2.keepBLSessions property you will get errors when using restored sessions.

Version:

$Id: CB2PlugIn.java,v 1.8 2004/04/28 15:12:08 levahim Exp $

Author:

Lev Himmelfarb

Constructor Summary

CB2PlugIn()

Method Summary

void	destroy() Destroys the plugin when the application goes down.
static CB2Application	getApplication(javax.servlet.ServletContext servletCtx) Finds the CB2Application instance for the web-application.
void	init(org.apache.struts.action.ActionServlet servlet, org.apache.struts.config.ModuleConfig config) Initialize the plugin for a module.
void	setController(java.lang.String controllerClassName) Sets the controller class name init parameter.
void	setLockedUrl(java.lang.String lockedUrl) Sets the URL of the "application is locked" page.
void	setPagesConfig(java.lang.String pagesConfig) Sets the pages config file URL init parameter.
void	setRequestCharEncoding(java.lang.String requestCharEncoding) Sets optional request character encoding.
void	setResponseContentType(java.lang.String responseContentType) Sets optional response content type.
void	setUistate(java.lang.String uiStateClassName) Sets the UI state bean class name init parameter.

Methods inherited from class java.lang.Object

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

Constructor Detail

CB2PlugIn

public CB2PlugIn()

Method Detail

setPagesConfig

public void setPagesConfig(java.lang.String pagesConfig)

Sets the pages config file URL init parameter.

Parameters:

pagesConfig - pages config file servlet context relative URL.

setController

public void setController(java.lang.String controllerClassName)

Sets the controller class name init parameter.

Parameters:

controllerClassName - the controller class name.

setUistate

public void setUistate(java.lang.String uiStateClassName)

Sets the UI state bean class name init parameter.

Parameters:

uiStateClassName - the UI state bean class name.

setLockedUrl

public void setLockedUrl(java.lang.String lockedUrl)

Sets the URL of the "application is locked" page.

Parameters:

lockedUrl - the page's URL.

setRequestCharEncoding

public void setRequestCharEncoding(java.lang.String requestCharEncoding)

Sets optional request character encoding.

Parameters:

requestCharEncoding - the request character encoding.

setResponseContentType

public void setResponseContentType(java.lang.String responseContentType)

Sets optional response content type.

Parameters:

responseContentType - the reponse content type string.

init

public void init(org.apache.struts.action.ActionServlet servlet,
                 org.apache.struts.config.ModuleConfig config)
          throws javax.servlet.ServletException

Initialize the plugin for a module. If this is the first, or the only module, then this method also creates and initializes such shared subsystems as the application context and business logic level manager.

Specified by:

init in interface org.apache.struts.action.PlugIn

Parameters:

servlet - reference to the Struts action servlet.

config - the module configuration.

Throws:

javax.servlet.ServletException - if the plugin cannot be initialized.

destroy

public void destroy()

Destroys the plugin when the application goes down. If this is the last, or the only module, then this method also destroys application context and business logic level manager.

Specified by:

destroy in interface org.apache.struts.action.PlugIn

getApplication

public static CB2Application getApplication(javax.servlet.ServletContext servletCtx)

Finds the CB2Application instance for the web-application.

Parameters:

servletCtx - the web-application's servlet context.

Returns:

reference to the CB2Application instance.