/***
* Copyright (c) 2009 Caelum - www.caelum.com.br/opensource
* All rights reserved.
*
* 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 br.com.caelum.vraptor.http.ognl;
import java.lang.reflect.Method;
import java.lang.reflect.ParameterizedType;
import java.lang.reflect.Type;
import java.util.List;
import net.vidageek.mirror.dsl.Mirror;
import ognl.Evaluation;
import br.com.caelum.vraptor.VRaptorException;
import br.com.caelum.vraptor.vraptor2.Info;
/**
* Capable of instantiating lists. These are registered for later removal of
* null entitres.
*
* @author Guilherme Silveira
*/
class ListNullHandler {
private final EmptyElementsRemoval removal;
public ListNullHandler(EmptyElementsRemoval removal) {
this.removal = removal;
}
@SuppressWarnings("unchecked")
Object instantiate(Object target, Object property, Type type) {
Class typeToInstantiate = (Class) ((ParameterizedType) type).getActualTypeArguments()[0];
Object instance = new Mirror().on(typeToInstantiate).invoke().constructor().withoutArgs();
// setting the position
int position = (Integer) property;
List list = (List) target;
while (list.size() <= position) {
list.add(null);
}
list.set(position, instance);
// registering for null entries removal
removal.add(list);
return instance;
}
Type getListType(Object target, Evaluation evaluation) {
// creating instance
Object listHolder = evaluation.getSource();
String listPropertyName = evaluation.getNode().toString();
Method listSetter = ReflectionBasedNullHandler.findMethod(listHolder.getClass(), "set"
+ Info.capitalize(listPropertyName), target.getClass(), null);
Type[] types = listSetter.getGenericParameterTypes();
Type type = types[0];
if (!(type instanceof ParameterizedType)) {
throw new VRaptorException("Vraptor does not support non-generic collection at "
+ listSetter.getName());
}
return type;
}
}