freemarker.template.utility.ObjectConstructor Maven / Gradle / Ivy

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/*
 * 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 [email protected].
 *
 * 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.template.utility;

import java.util.List;
import freemarker.ext.beans.BeansWrapper;
import freemarker.template.*;
import freemarker.template.utility.ClassUtil;

/**
 * An object that you can make available in a template
 * to instantiate arbitrary beans-wrapped objects in a template.
 * Beware of this class's security implications. It allows
 * the instantiation of arbitrary objects and invoking 
 * methods on them. Usage is something like:
 * 

 * 
myDataModel.put("objectConstructor", new ObjectConstructor());
 * 

 * 
And then from your FTL code:
 * 

 * 
<#assign aList = objectConstructor("java.util.ArrayList", 100)>
 */

public class ObjectConstructor implements TemplateMethodModelEx
{
    public Object exec(List args) throws TemplateModelException {
        if (args.isEmpty()) {
            throw new TemplateModelException("This method must have at least one argument, the name of the class to instantiate.");
        }
        String classname = args.get(0).toString();
        Class cl = null;
        try {
            cl = ClassUtil.forName(classname);
        }
        catch (Exception e) {
            throw new TemplateModelException(e.getMessage());
        }
        BeansWrapper bw = BeansWrapper.getDefaultInstance();
        Object obj = bw.newInstance(cl, args.subList(1, args.size()));
        return bw.wrap(obj);
    }
}