src/main/java/freemarker/ext/servlet/HttpRequestParametersHashModel.java

/*
 * Copyright (c) 2003 The Visigoth Software Society. All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowledgement:
 *       "This product includes software developed by the
 *        Visigoth Software Society (http://www.visigoths.org/)."
 *    Alternately, this acknowledgement may appear in the software itself,
 *    if and wherever such third-party acknowledgements normally appear.
 *
 * 4. Neither the name "FreeMarker", "Visigoth", nor any of the names of the 
 *    project contributors may be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact visigoths@visigoths.org.
 *
 * 5. Products derived from this software may not be called "FreeMarker" or "Visigoth"
 *    nor may "FreeMarker" or "Visigoth" appear in their names
 *    without prior written permission of the Visigoth Software Society.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE VISIGOTH SOFTWARE SOCIETY OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Visigoth Software Society. For more
 * information on the Visigoth Software Society, please see
 * http://www.visigoths.org/
 */

package freemarker.ext.servlet;

import java.util.ArrayList;
import java.util.Enumeration;
import java.util.Iterator;
import java.util.List;

import javax.servlet.http.HttpServletRequest;

import freemarker.template.SimpleCollection;
import freemarker.template.SimpleScalar;
import freemarker.template.TemplateCollectionModel;
import freemarker.template.TemplateHashModelEx;
import freemarker.template.TemplateModel;

/**
 * TemplateHashModel wrapper for a HttpServletRequest parameters.
 * @author Attila Szegedi
 */

public class HttpRequestParametersHashModel
    implements
    TemplateHashModelEx
{
    private final HttpServletRequest request;
    private List keys;
        
    public HttpRequestParametersHashModel(HttpServletRequest request)
    {
        this.request = request;
    }

    public TemplateModel get(String key)
    {
        String value = request.getParameter(key);
        return value == null ? null : new SimpleScalar(value);
    }

    public boolean isEmpty()
    {
        return !request.getParameterNames().hasMoreElements();
    }
    
    public int size() {
        return getKeys().size();
    }
    
    public TemplateCollectionModel keys() {
        return new SimpleCollection(getKeys().iterator());
    }
    
    public TemplateCollectionModel values() {
        final Iterator iter = getKeys().iterator();
        return new SimpleCollection(
            new Iterator() {
                public boolean hasNext() {
                    return iter.hasNext();
                }
                public Object next() {
                    return request.getParameter((String)iter.next()); 
                }
                public void remove() {
                    throw new UnsupportedOperationException();
                }
            });
    }

    protected String transcode(String string)
    {
        return string;
    }

    private synchronized List getKeys() {
        if(keys == null) {
            keys = new ArrayList();
            for (Enumeration enumeration = request.getParameterNames(); enumeration.hasMoreElements();) {
                keys.add(enumeration.nextElement());
            }
        }
        return keys;
    }
}