org.opensubsystems.core.www
Class WebUIServlet

java.lang.Object
  javax.servlet.GenericServlet
      javax.servlet.http.HttpServlet
          org.opensubsystems.core.www.WebSessionServlet
              org.opensubsystems.core.www.WebUIServlet

All Implemented Interfaces:

java.io.Serializable, javax.servlet.Servlet, javax.servlet.ServletConfig

Direct Known Subclasses:

WebUIDispatchServlet

public class WebUIServlet
extends WebSessionServlet

Base class for all servlets developed as part of this project, which perform web form processing or execute an action based on request from the user interface. It's main responsibility is to provide default implementation if functionality for form processing is required.

Version:

$Id: WebUIServlet.java,v 1.16 2007/02/20 04:12:15 bastafidli Exp $

Author:

Miro Halas

See Also:

Serialized Form

Code reviewer:

Miro Halas

Code reviewed:

1.9 2006/02/24 00:19:55 jlegeny

Field Summary

static java.lang.String	DATA_ATTRIBUTE_REQUEST_PARAM Name of the generic attribute used to pass some data to the rendering page.
static java.lang.String	FORCE_MAXIMIZE_PARAM Name of the attribute used to pass flag if the dialog has to be maximized.
static int	FORM_COUNT_WEBUI Constants for number of forms recognized by this servlet
static java.lang.String	FORM_NAME_REQUEST_PARAM Parameter used to identify form to be processed.
static int	FORM_UNKNOWN_ID Constants for forms recognized by this servlet
static java.lang.String	LOGGEDIN_REQUEST_PARAM Name of the attribute used to pass flag if the user is logged in.
protected java.lang.String	m_strMessageStyleSheet Style sheet used for message boxes if any.
static java.lang.String	ORIGINAL_REQUEST_INFO_REQUEST_PARAM Name of the generic attribute used to pass some string representation of the current request to the message box page in case it wants to display some troubleshooting information.
static java.lang.String	PAGE_TITLE_REQUEST_PARAM Name of the attribute used to pass page title to the rendering pages.
static java.lang.String	WEBUI_MESSAGEBOX_PAGE Property used to specify page to display messages to user for example in case of error.
static java.lang.String	WEBUI_MESSAGEBOX_STYLE_SHEET Property used to specify stylesheet used to display messages to user for example in case of error.

Fields inherited from class org.opensubsystems.core.www.WebSessionServlet

APPLICATION_SECURE, ATTACH_INTERNAL_SESSION_ID_URL_PARAM, DEFAULT_APPLICATION_SECURE, DEFAULT_LOGIN_SECURE, LOGIN_FORWARD_SESSION_PARAM, LOGIN_SECURE, m_scServletContext, m_sessionValidator, m_strHandshakeURL, s_bApplicationSecure, s_bLoginSecure, SERVLET_PATH_REQUEST_PARAM, SESSION_VALIDATOR_CLASS, WEBSESSION_DISPATCHER_CACHED, WEBSESSION_DISPATCHER_CACHED_DEFAULT, WEBSESSION_HADSHAKE_REQUIRED_DEFAULT, WEBSESSION_HANDSHAKE_REQUIRED, WEBSESSION_HANDSHAKE_URL, WEBSESSION_LOGIN_REQUIRED, WEBSESSION_LOGIN_REQUIRED_DEFAULT, WEBSESSION_LOGIN_URL

Constructor Summary

WebUIServlet()

Method Summary

protected void	cacheDispatcher(java.lang.String strUIID, java.lang.String strUIPath) Cache dispatcher to given resource if caching is possible.
protected void	cacheUIPath(javax.servlet.ServletConfig scConfig, java.lang.String strUIID, java.lang.String strErrorMessage) Cache path to portion of user interface by first search servlet configuration information and if not found then other predefined locations.
protected void	displayUI(java.lang.String strUIID, javax.servlet.http.HttpServletRequest hsrqRequest, javax.servlet.http.HttpServletResponse hsrpResponse) Get handle to resource responsible for rendering of specified part of UI
protected int	getFormToProcess(javax.servlet.http.HttpServletRequest hsrqRequest) Examine request and find out what form needs to be processed.
java.lang.String	getServletInfo()
void	init(javax.servlet.ServletConfig scConfig)
protected void	messageBoxPage(javax.servlet.http.HttpServletRequest hsrqRequest, javax.servlet.http.HttpServletResponse hsrpResponse, java.lang.String strPageTitle, java.lang.String strMessage, java.lang.String strProceedURL, java.lang.Throwable cause) Display page with a message to the user.
protected void	messageBoxPage(javax.servlet.http.HttpServletRequest hsrqRequest, javax.servlet.http.HttpServletResponse hsrpResponse, java.lang.String strPageTitle, java.lang.String strMessage, java.lang.String strProceedURL, java.lang.Throwable cause, java.lang.String strUIPage) Display page with a message to the user, when there was a file error.
protected void	preservice(javax.servlet.http.HttpSession hsSession, javax.servlet.http.HttpServletRequest hsrqRequest, javax.servlet.http.HttpServletResponse hsrpResponse, boolean bLoginVerified) This method gives derived servlets execute common logic which needs to be executed for each request.
protected void	setLoggedInFlag(javax.servlet.http.HttpServletRequest hsrqRequest, javax.servlet.http.HttpServletResponse hsrpResponse) If the user has logged in, this method will set necessary flag to mark the page that way.

Methods inherited from class org.opensubsystems.core.www.WebSessionServlet

destroy, getLoginRedirect, handleNewSession, isApplicationSecure, isDispatcherCachingEnabled, isLoginSecure, redirect, redirectToHandshake, redirectToLogin, resetLoginRedirect, saveLoginRedirect, service, shouldRequestBeSecure, verifyLogin

Methods inherited from class javax.servlet.http.HttpServlet

doDelete, doGet, doHead, doOptions, doPost, doPut, doTrace, getLastModified, service

Methods inherited from class javax.servlet.GenericServlet

getInitParameter, getInitParameterNames, getServletConfig, getServletContext, getServletName, init, log, log

Methods inherited from class java.lang.Object

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

Field Detail

WEBUI_MESSAGEBOX_PAGE

public static final java.lang.String WEBUI_MESSAGEBOX_PAGE

Property used to specify page to display messages to user for example in case of error.

See Also:

Constant Field Values

WEBUI_MESSAGEBOX_STYLE_SHEET

public static final java.lang.String WEBUI_MESSAGEBOX_STYLE_SHEET

Property used to specify stylesheet used to display messages to user for example in case of error.

See Also:

Constant Field Values

ORIGINAL_REQUEST_INFO_REQUEST_PARAM

public static final java.lang.String ORIGINAL_REQUEST_INFO_REQUEST_PARAM

Name of the generic attribute used to pass some string representation of the current request to the message box page in case it wants to display some troubleshooting information.

See Also:

Constant Field Values

DATA_ATTRIBUTE_REQUEST_PARAM

public static final java.lang.String DATA_ATTRIBUTE_REQUEST_PARAM

Name of the generic attribute used to pass some data to the rendering page. Any aditional data can be passed in attributed named "databean2", "databean3", etc.

See Also:

Constant Field Values

PAGE_TITLE_REQUEST_PARAM

public static final java.lang.String PAGE_TITLE_REQUEST_PARAM

Name of the attribute used to pass page title to the rendering pages.

See Also:

Constant Field Values

LOGGEDIN_REQUEST_PARAM

public static final java.lang.String LOGGEDIN_REQUEST_PARAM

Name of the attribute used to pass flag if the user is logged in.

See Also:

Constant Field Values

FORCE_MAXIMIZE_PARAM

public static final java.lang.String FORCE_MAXIMIZE_PARAM

Name of the attribute used to pass flag if the dialog has to be maximized.

See Also:

Constant Field Values

FORM_NAME_REQUEST_PARAM

public static final java.lang.String FORM_NAME_REQUEST_PARAM

Parameter used to identify form to be processed.

See Also:

FORM_UNKNOWN_ID, getFormToProcess(javax.servlet.http.HttpServletRequest), Constant Field Values

FORM_UNKNOWN_ID

public static final int FORM_UNKNOWN_ID

Constants for forms recognized by this servlet

See Also:

FORM_NAME_REQUEST_PARAM, getFormToProcess(javax.servlet.http.HttpServletRequest), Constant Field Values

FORM_COUNT_WEBUI

public static final int FORM_COUNT_WEBUI

Constants for number of forms recognized by this servlet

See Also:

Constant Field Values

m_strMessageStyleSheet

protected java.lang.String m_strMessageStyleSheet

Style sheet used for message boxes if any.

Constructor Detail

WebUIServlet

public WebUIServlet()

Method Detail

init

public void init(javax.servlet.ServletConfig scConfig)
          throws javax.servlet.ServletException

Specified by:

init in interface javax.servlet.Servlet

Overrides:

init in class WebSessionServlet

Throws:

javax.servlet.ServletException

getServletInfo

public java.lang.String getServletInfo()

Specified by:

getServletInfo in interface javax.servlet.Servlet

Overrides:

getServletInfo in class WebSessionServlet

preservice

protected void preservice(javax.servlet.http.HttpSession hsSession,
                          javax.servlet.http.HttpServletRequest hsrqRequest,
                          javax.servlet.http.HttpServletResponse hsrpResponse,
                          boolean bLoginVerified)
                   throws javax.servlet.ServletException,
                          java.io.IOException

This method gives derived servlets execute common logic which needs to be executed for each request. It is executed right before the service itself once handshake was established (if required), login was verified (if required) and identity of user if one is logged in was established. It can also be called if login is required and we are redirecting to the login page.

Overrides:

preservice in class WebSessionServlet

Parameters:

hsSession - - HTTP session object

hsrqRequest - - the servlet request.

hsrpResponse - - the servlet response.

bLoginVerified - - true if login was verified or it is not required, false if we are redirecting to the login page

Throws:

javax.servlet.ServletException - - problems redirecting to login

java.io.IOException - - problems redirecting to login

cacheUIPath

protected final void cacheUIPath(javax.servlet.ServletConfig scConfig,
                                 java.lang.String strUIID,
                                 java.lang.String strErrorMessage)
                          throws javax.servlet.ServletException

Cache path to portion of user interface by first search servlet configuration information and if not found then other predefined locations.

Parameters:

scConfig - - servlet config to read parameters from

strUIID - - unique ID of the configuration parameter used to specify user interface which is URL or path to some kind of rendering page (e.g. JSP page)

strErrorMessage - - error message to display if the path doesn't exist

Throws:

javax.servlet.ServletException - - problem finding the specified UI

cacheDispatcher

protected final void cacheDispatcher(java.lang.String strUIID,
                                     java.lang.String strUIPath)
                              throws javax.servlet.ServletException

Cache dispatcher to given resource if caching is possible.

Parameters:

strUIID - - unique ID of the configuration parameter used to specify this UI

strUIPath - - path to given resource

Throws:

javax.servlet.ServletException - - problem finding the specified UI

displayUI

protected final void displayUI(java.lang.String strUIID,
                               javax.servlet.http.HttpServletRequest hsrqRequest,
                               javax.servlet.http.HttpServletResponse hsrpResponse)
                        throws javax.servlet.ServletException,
                               java.io.IOException

Get handle to resource responsible for rendering of specified part of UI

Parameters:

strUIID - - unique ID of the configuration parameter used to specify UI to display. This is the same ID previously passed into cacheUIPath method.

hsrqRequest - - the servlet request.

hsrpResponse - - the servlet response.

Throws:

javax.servlet.ServletException - - problems displaying UI

java.io.IOException - - problems displaying UI

setLoggedInFlag

protected void setLoggedInFlag(javax.servlet.http.HttpServletRequest hsrqRequest,
                               javax.servlet.http.HttpServletResponse hsrpResponse)

If the user has logged in, this method will set necessary flag to mark the page that way. User is logged in if the session exists and user name is set as session attribute. If user is not logged in, the flag will be set to the flag to false.

Parameters:

hsrqRequest - - the servlet request.

hsrpResponse - - the servlet response.

messageBoxPage

protected void messageBoxPage(javax.servlet.http.HttpServletRequest hsrqRequest,
                              javax.servlet.http.HttpServletResponse hsrpResponse,
                              java.lang.String strPageTitle,
                              java.lang.String strMessage,
                              java.lang.String strProceedURL,
                              java.lang.Throwable cause)
                       throws java.io.IOException,
                              javax.servlet.ServletException

Display page with a message to the user.

Parameters:

hsrqRequest - - the servlet request.

hsrpResponse - - the servlet response.

strPageTitle - - title of the message box

strMessage - - message to display in the message box

strProceedURL - - what URL to proceed to

cause - - what was the cause of the problem if any

Throws:

javax.servlet.ServletException - - an error has occured while displaying message box

java.io.IOException - - error writing response

messageBoxPage

protected void messageBoxPage(javax.servlet.http.HttpServletRequest hsrqRequest,
                              javax.servlet.http.HttpServletResponse hsrpResponse,
                              java.lang.String strPageTitle,
                              java.lang.String strMessage,
                              java.lang.String strProceedURL,
                              java.lang.Throwable cause,
                              java.lang.String strUIPage)
                       throws java.io.IOException,
                              javax.servlet.ServletException

Display page with a message to the user, when there was a file error.

Parameters:

hsrqRequest - - the servlet request.

hsrpResponse - - the servlet response.

strPageTitle - - title of the message box

strMessage - - message to display in the file message box

strProceedURL - - what URL to proceed to

cause - - what was the cause of the problem if any

strUIPage - -

Throws:

javax.servlet.ServletException - - an error has occured while displaying file message box

java.io.IOException - - error writing response

getFormToProcess

protected int getFormToProcess(javax.servlet.http.HttpServletRequest hsrqRequest)

Examine request and find out what form needs to be processed. Unique number assigned to the form will be returned

Parameters:

hsrqRequest - - the servlet request, which is used to find out what form needs to be processed

Returns:

int - one of the FORM_XXX constants