/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* Licensed 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 freemarker.template.utility;
import java.util.List;
import freemarker.ext.beans.BeansWrapper;
import freemarker.template.TemplateMethodModelEx;
import freemarker.template.TemplateModelException;
/**
* 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:
* <br>
* <br>myDataModel.put("objectConstructor", new ObjectConstructor());
* <br>
* <br>And then from your FTL code:
* <br>
* <br><#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);
}
}