freemarker.ext.beans.MapModel Maven / Gradle / Ivy
/*
* 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 freemarker.ext.beans;
import java.util.List;
import java.util.Map;
import java.util.Set;
import freemarker.ext.util.ModelFactory;
import freemarker.template.ObjectWrapper;
import freemarker.template.TemplateMethodModelEx;
import freemarker.template.TemplateModel;
import freemarker.template.TemplateModelException;
/**
* A special case of {@link BeanModel} that adds implementation
* for {@link TemplateMethodModelEx} on map objects that is a shortcut for the
* Map.get() method. Note that if the passed argument itself is a
* reflection-wrapper model, then the map lookup will be performed using the
* wrapped object as the key. Note that you can call get() using the
* map.key syntax inherited from {@link BeanModel} as well,
* however in that case the key is always a string.
* The class itself does not implement the {@link freemarker.template.TemplateCollectionModel}.
* You can, however use map.entrySet(), map.keySet(), or
* map.values() to obtain {@link freemarker.template.TemplateCollectionModel} instances for
* various aspects of the map.
*/
public class MapModel
extends
StringModel
implements
TemplateMethodModelEx {
static final ModelFactory FACTORY =
new ModelFactory()
{
public TemplateModel create(Object object, ObjectWrapper wrapper) {
return new MapModel((Map) object, (BeansWrapper) wrapper);
}
};
/**
* Creates a new model that wraps the specified map object.
* @param map the map object to wrap into a model.
* @param wrapper the {@link BeansWrapper} associated with this model.
* Every model has to have an associated {@link BeansWrapper} instance. The
* model gains many attributes from its wrapper, including the caching
* behavior, method exposure level, method-over-item shadowing policy etc.
*/
public MapModel(Map map, BeansWrapper wrapper) {
super(map, wrapper);
}
/**
* The first argument is used as a key to call the map's get method.
*/
public Object exec(List arguments)
throws TemplateModelException {
Object key = unwrap((TemplateModel) arguments.get(0));
return wrap(((Map) object).get(key));
}
/**
* Overridden to invoke the generic get method by casting to Map instead of
* through reflection - should yield better performance.
*/
@Override
protected TemplateModel invokeGenericGet(Map keyMap, Class clazz, String key)
throws TemplateModelException {
Map map = (Map) object;
Object val = map.get(key);
if (val == null) {
if (key.length() == 1) {
// just check for Character key if this is a single-character string
Character charKey = Character.valueOf(key.charAt(0));
val = map.get(charKey);
if (val == null && !(map.containsKey(key) || map.containsKey(charKey))) {
return UNKNOWN;
}
} else if (!map.containsKey(key)) {
return UNKNOWN;
}
}
return wrap(val);
}
@Override
public boolean isEmpty() {
return ((Map) object).isEmpty() && super.isEmpty();
}
@Override
public int size() {
return keySet().size();
}
@Override
protected Set keySet() {
Set set = super.keySet();
set.addAll(((Map) object).keySet());
return set;
}
}