ro.cs.cm.web.common.MultiFormBeanCheckingInterceptor.java Source code

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Here is the source code for ro.cs.cm.web.common.MultiFormBeanCheckingInterceptor.java

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/*******************************************************************************
 * This file is part of Termitaria, a project management tool 
 *  Copyright (C) 2008-2013 CodeSphere S.R.L., www.codesphere.ro
 *   
 *  Termitaria is free software; you can redistribute it and/or 
 *  modify it under the terms of the GNU Affero General Public License 
 *  as published by the Free Software Foundation; either version 3 of 
 *  the License, or (at your option) any later version.
 *  
 *  This program is distributed in the hope that it will be useful, 
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of 
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the 
 *  GNU Affero General Public License for more details.
 *  
 *  You should have received a copy of the GNU Affero General Public License 
 *  along with Termitaria. If not, see  <http://www.gnu.org/licenses/> .
 ******************************************************************************/
package ro.cs.cm.web.common;

import java.util.HashMap;
import java.util.Map;
import java.util.Vector;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.springframework.beans.factory.BeanInitializationException;
import org.springframework.web.servlet.ModelAndView;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;
import org.springframework.web.servlet.mvc.AbstractFormController;

public class MultiFormBeanCheckingInterceptor<K extends AbstractFormController> extends HandlerInterceptorAdapter {

    private Log logger = LogFactory.getLog(getClass());

    /**
    * Stores the references between controllers and classes to create. Use a
    * Hashmap containing a string key and vector of the commands.
    */
    private Map<String, Vector<K>> controllers = new HashMap<String, Vector<K>>();

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler,
            ModelAndView modelAndView) throws Exception {

        // at this point the controller has executed and returned a model so lets
        // go sort out what we need to do.
        String viewName = this.getViewName(modelAndView.getViewName());
        this.logger.debug("Post processing view: " + viewName);

        // Now get the vector for the view.
        Vector<K> controllerList = this.getControllers().get(viewName);
        if (controllerList == null) {
            this.logger.debug("View is not in list. Exiting.");
            return;
        }

        // Loop and create the beans.
        String beanKey;
        String cmdName;
        Object cmdBean;
        Class cmdClass;
        boolean sessionBeanFound;
        boolean modelBeanFound;
        for (K c : controllerList) {

            cmdName = c.getCommandName();
            cmdClass = c.getCommandClass();
            beanKey = c.getClass().getName() + ".FORM." + cmdName;

            Map<String, Object> model = modelAndView.getModel();

            //Look for an establish bean we can use.
            sessionBeanFound = request.getSession().getAttribute(beanKey) != null;
            modelBeanFound = model.containsKey(cmdName);

            //Try and get a reference to an established bean using either
            //the session bean or model bean. Otherwise create a new one.
            if (sessionBeanFound) {
                this.logger.debug("Bean present under id:" + beanKey);
                cmdBean = request.getSession().getAttribute(beanKey);
            } else if (modelBeanFound) {
                this.logger.debug("Bean present in model.");
                cmdBean = model.get(cmdName);
            } else {
                this.logger.debug("Creating new bean.");
                cmdBean = cmdClass.newInstance();
            }

            //Now put the bean in session and model if not already there.
            request.getSession().setAttribute(beanKey, cmdBean);
            model.put(cmdName, cmdBean);

        }

        // Done, call the parent.
        super.postHandle(request, response, handler, modelAndView);
    }

    /**
    * Set to store the data.
    *
    * @param controllers
    *           A Map containing the revelant controllers as keys and name of
    *           the property on then that returns the view name as the value.
    */
    public void setControllers(Map<K, String> controllers) {

        // Loop through the passed controllers and assemble the data.
        String viewName;
        for (K c : controllers.keySet()) {

            this.logger.debug("Setting controller form bean for " + c.getCommandName());

            if (!c.isSessionForm()) {
                throw new BeanInitializationException("Controller is not set for session beans.");
            }

            // get the view name.
            try {
                viewName = this.getViewName((String) controllers.get(c));
                this.logger.debug(viewName + " => bean " + c.getCommandClass().getName());
            } catch (Exception e) {
                throw new BeanInitializationException("Could not extract view name from controller", e);
            }

            // Check and create a vector for it .
            if (!this.controllers.containsKey(viewName)) {
                this.controllers.put(viewName, new Vector<K>());
            }

            // Now add the controller to the list,
            this.controllers.get(viewName).add(c);
        }
    }

    /**
    * Internal routine used to strip redirect: off the front of the view names
    * and suffixes off the back so
    * we can find them correctly regardless of whether they are doing
    * redirects.
    */
    private String getViewName(String viewName) {
        String view[] = viewName.split("[:\\.]");
        switch (view.length) {
        case 1:
            return viewName;
        case 2:
            return view[0].equalsIgnoreCase("redirect") ? view[1] : view[0];
        case 3:
            return view[1];
        default:
            throw new IllegalArgumentException(viewName + " does not appear to be a valid view.");
        }

    }

    public Map<String, Vector<K>> getControllers() {
        return controllers;
    }

}