logout_engine.java

java 写的一个新闻发布系统

//
//                                   ____.
//                       __/\ ______|    |__/\.     _______
//            __   .____|    |       \   |    +----+       \
//    _______|  /--|    |    |    -   \  _    |    :    -   \_________
//   \\______: :---|    :    :           |    :    |         \________>
//           |__\---\_____________:______:    :____|____:_____\
//                                      /_____|
//
//                 . . . i n   j a h i a   w e   t r u s t . . .
//

//
//  Logout_Engine
//	(No user interaction, just plain raw hardkore logout ;)
//  EV  23.01.2001
//
//  getInstance()
//  authoriseRender()
//  renderLink()
//  needsJahiaData()
//  handleActions()
//

package org.jahia.engines.logout;

import java.util.*;                                 // HashMap
import javax.servlet.http.*;                        // HttpSession

import org.jahia.exceptions.*;                  // JahiaException
import org.jahia.utils.*;                       // JahiaConsole
import org.jahia.data.*;                        // JahiaData, ConnectionTypes
import org.jahia.params.*;                      // ParamBean
import org.jahia.registries.*;                  // ServicesRegistry
import org.jahia.engines.*;                     // JahiaEngine interface
import org.jahia.engines.core.*;                // JahiaCoreEngine
import org.jahia.data.events.*;                 // JahiaEvent
import org.jahia.services.pages.*;		        // JahiaPage
import org.jahia.services.sites.*;		        // JahiaSite
import org.jahia.services.usermanager.*;        // JahiaUserManager



public class Logout_Engine implements JahiaEngine {

    private static          Logout_Engine        theObject   = null;
    private                 String              engineName  = "logout";
    private                 EngineToolBox       toolBox;


    /***
        * constructor
        *
        */
    private Logout_Engine()
    {
        // JahiaConsole.println( "Engine", "***** Starting Logout Engine *****" );
        toolBox = EngineToolBox.getInstance();
    } // end constructor



    /***
        * returns a single instance of the object
        *
        */
    public static synchronized Logout_Engine getInstance()
    {
        if (theObject == null) {
            theObject = new Logout_Engine();
        }
        return theObject;
    } // end getInstance



    /***
        * authorises engine render
        *
        */
    public boolean authoriseRender( ParamBean jParams )
    {
        return true;					// always allowed to render logout!
    } // end authoriseRender



    /***
        * renders link to pop-up window
        *
        */
    public String renderLink( ParamBean jParams, Object theObj )
    throws JahiaException
    {
        /**
         * @todo This is very ugly... what are we doing here exactly ?
         */
        String theUrl = jParams.composeEngineUrl( engineName, "" );

        if (theObj != null)  {
            // we remove the /pid/../ part of the URL here ?
            int pidNamePos = theUrl.indexOf( "/pid/" );
            int pidValuePos = theUrl.indexOf( "/", pidNamePos + 5 );
            pidValuePos = (pidValuePos > -1) ? pidValuePos : theUrl.length();
            String myString = theObj.toString();
            myString.replace('&','/');
            myString.replace(';','/');
            theUrl = theUrl.substring(0,pidNamePos) + theUrl.substring(pidValuePos,theUrl.length()) + myString;
            theUrl += "?engine_params=logout";
        }

        return jParams.getResponse().encodeURL(theUrl);
    } // end renderLink



    /***
        * specifies if the engine needs the JahiaData object
        *
        */
    public boolean needsJahiaData( ParamBean jParams )
    {
        return false;		// we need the jData because we are forwarding the request
                            // to the "core" engine!
    } // end needsJahiaData



    /***
        * handles the engine actions
        *
        * @param        jParams             a ParamBean object
        * @param        jData               a JahiaData object (not mandatory)
        *
        */
    public void handleActions( ParamBean jParams, JahiaData jData )
    throws JahiaException
    {
        String engineParams	= jParams.getRequest().getParameter ( "engine_params" );

        JahiaPage logoutPage = null;

        // if there is no engineparams, it just means that the engine is still set to
        // logout, but in fact the user wants to call "core". This is because a user
        // logs outs, the page is reloaded but still with engine "logout".
        if ((engineParams!=null) && (engineParams.equals("logout")))
        {
            JahiaConsole.finalPrintln("Logout_Engine","User " + jParams.getUser().getName() + " logged out.");
            // send a new logout event !
            JahiaEvent theEvent = new JahiaEvent( this, jParams, jParams.getUser() );
            ServicesRegistry.getInstance().getJahiaEventService().fireLogout( theEvent );

            logoutPage = getLogoutPage(jData);

            // if we were in edit mode, let's destroy the cache's entry for this page and this user.
            if (jParams.EDIT.equals(jParams.getOperationMode())) {
                ServicesRegistry.getInstance().getCacheServerService().removeUserEntries(jParams.getUser().getUsername());
            }
            // destroys all the session objects and creates a new one
            // jParams.invalidateSession();
            jParams.purgeSession();
            // set current user to guest
            jParams.setUserGuest(jParams.getSiteID());
        }

        if ( logoutPage == null ){
            // current page do not have read
            throw new JahiaException( "403 Forbidden - Page:"+ jParams.getPageID(),
                        "No read access for page " + jParams.getPageID(),
                        JahiaException.SECURITY_ERROR,
                        JahiaException.ERROR );
        } else {
            // get the logout page with template
            try {
                JahiaPageBaseService pageService = JahiaPageBaseService.getInstance();
                logoutPage = (JahiaPage)pageService
                    .lookupPage (logoutPage.getID(),jParams);
            } catch ( Throwable t ){
                t.printStackTrace();
            }

            if ( logoutPage == null ) {
                throw new JahiaException( "404 Page not found "+ logoutPage.getID(),
                        "Logout page not found " + logoutPage.getID(),
                        JahiaException.SECURITY_ERROR,
                        JahiaException.ERROR );
            }

            // change the page
            jParams.changePage(logoutPage);
        }
        JahiaData jData2 = new JahiaData( jParams );
        ((JahiaEngine)EnginesRegistry.getInstance().getEngine("core")).handleActions( jParams, jData2 );
    } // end handleActions


    //--------------------------------------------------------------------------
    /**
     * Check for a "friendly" logout page instead of a "403 Forbidden " page,
     * when the user loggout.
     *
     * @param JahiaPage a page, can be null if no page available.
     * @auhtor NK
     */
    private JahiaPage getLogoutPage( JahiaData jData ){

        JahiaUser user = jData.params().getUser();
        JahiaPage page = jData.params().getPage();
        JahiaSite site = jData.params().getSite();

        if ( page == null || user == null || site == null )
            return null;

        if ( page.checkGuestAccess(site.getID()) )
            // he can stay at current page.
            return page;

        // look at the user homepages
        try {

            JahiaPageBaseService pageService = JahiaPageBaseService.getInstance();

            // get user home page
            if ( user.getHomepageID() >= 0 ){

                try {
                    page = (JahiaPage)pageService
                                .lookupPageWhitoutTemplates (user.getHomepageID());
                    if ( (page != null) && page.checkGuestAccess(site.getID()) )
                        return page; // return the user home page
                } catch ( Throwable t ){
                    t.printStackTrace();
                }
            }

            // get group homepages
            JahiaGroupManagerService grpServ =
                    ServicesRegistry.getInstance().getJahiaGroupManagerService();

            Vector v = grpServ.getUserMembership(user);
            int size = v.size();
            String grpKey = null;
            JahiaGroup grp = null;
            for ( int i=0 ; i<size ; i++ ){
                grpKey = (String)v.get(i);
                grp = grpServ.lookupGroup(grpKey);
                if ( grp != null
                        && grp.getSiteID() == site.getID()
                        && grp.getHomepageID() >=0 ){

                    try {
                        page = (JahiaPage)pageService
                            .lookupPageWhitoutTemplates (grp.getHomepageID());
                        if ( (page != null) && page.checkGuestAccess(site.getID()) )
                            return page;// return the user first available group home page
                                        // TODO -> have a default homepage per user !!! Pol is doing it

                    } catch ( Throwable t ){
                        t.printStackTrace();
                    }
                }
            }

            // if none available check if user has guest access on the site's homepage
            try {
                page = (JahiaPage)pageService
                    .lookupPageWhitoutTemplates (site.getHomePageID());
                if ( (page != null) && page.checkGuestAccess(site.getID()) )
                    return page;

            } catch ( Throwable t ){
                t.printStackTrace();
            }

        } catch (Throwable t) {
            t.printStackTrace();
        }
        return null; // no page available...
    }

} // end Logout_Engine