Struts example source code file (ScopesHashModel.java)

This example Struts source code file (ScopesHashModel.java) is included in the DevDaily.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Java - Struts tags/keywords

hashmap, http, httpservletrequest, map, object, object, request, response, scopeshashmodel, scopeshashmodel, servlet, servletcontext, servletcontext, simplehash, templatemodel, templatemodel, templatemodelexception, util, valuestack

The Struts ScopesHashModel.java source code

/*
 * $Id: ScopesHashModel.java 835248 2009-11-12 06:06:40Z musachy $
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *  http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package org.apache.struts2.views.freemarker;

import javax.servlet.ServletContext;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpSession;

import com.opensymphony.xwork2.util.ValueStack;

import freemarker.template.ObjectWrapper;
import freemarker.template.SimpleHash;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;

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


/**
 * Simple Hash model that also searches other scopes.
 * <p/>
 * If the key doesn't exist in this hash, this template model tries to
 * resolve the key within the attributes of the following scopes,
 * in the order stated: Request, Session, Servlet Context
 *
 * Updated to subclass AllHttpScopesHashModel.java to incorporate invisible scopes and compatibility with freemarker.
 */
public class ScopesHashModel extends SimpleHash implements TemplateModel {

    private static final long serialVersionUID = 5551686380141886764L;

    private HttpServletRequest request;
    private ServletContext servletContext;
    private ValueStack stack;
    private final Map<String,TemplateModel> unlistedModels = new HashMap();


    public ScopesHashModel(ObjectWrapper objectWrapper, ServletContext context, HttpServletRequest request, ValueStack stack) {
        super(objectWrapper);
        this.servletContext = context;
        this.request = request;
        this.stack = stack;
    }

    // This constructor is for Freemarker Sitemesh integration where the model is somehow lost...
    public ScopesHashModel(ObjectWrapper objectWrapper, ServletContext context, HttpServletRequest request) {
         super(objectWrapper);
         this.servletContext = context;
         this.request = request;
    }

    /**
     * Stores a model in the hash so that it doesn't show up in <tt>keys()
     * and <tt>values() methods. Used to put the Application, Session,
     * Request, RequestParameters and JspTaglibs objects.
     * @param key the key under which the model is stored
     * @param model the stored model
     */
    public void putUnlistedModel(String key, TemplateModel model) {
        unlistedModels.put(key, model);
    }

    public TemplateModel get(String key) throws TemplateModelException {
        // Lookup in default scope
        TemplateModel model = super.get(key);

        if (model != null) {
            return model;
        }


        if (stack != null) {
            Object obj = stack.findValue(key);

            if (obj != null) {
                return wrap(obj);
            }

            // ok, then try the context
            obj = stack.getContext().get(key);
            if (obj != null) {
                return wrap(obj);
            }
        }

        if (request != null) {
            // Lookup in request scope
            Object obj = request.getAttribute(key);

            if (obj != null) {
                return wrap(obj);
            }

            // Lookup in session scope
            HttpSession session = request.getSession(false);

            if (session != null) {
                obj = session.getAttribute(key);

                if (obj != null) {
                    return wrap(obj);
                }
            }
        }

        if (servletContext != null) {
            // Lookup in application scope
            Object obj = servletContext.getAttribute(key);

            if (obj != null) {
                return wrap(obj);
            }
        }

        // Look in unlisted models
        model = unlistedModels.get(key);
        if(model != null) {
            return wrap(model);
        }


        return null;
    }

    public void put(String string, boolean b) {
        super.put(string, b);
    }

    public void put(String string, Object object) {
        super.put(string, object);
    }
}