freemarker.template.DefaultMapAdapter 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.template;
import java.io.Serializable;
import java.util.Map;
import java.util.SortedMap;
import freemarker.core._DelayedJQuote;
import freemarker.core._TemplateModelException;
import freemarker.ext.util.WrapperTemplateModel;
import freemarker.template.utility.ObjectWrapperWithAPISupport;
/**
* Adapts a {@link Map} to the corresponding {@link TemplateModel} interface(s), most importantly to
* {@link TemplateHashModelEx}. If you aren't wrapping an already existing {@link Map}, but build a hash specifically to
* be used from a template, also consider using {@link SimpleHash} (see comparison there).
*
*
* Thread safety: A {@link DefaultMapAdapter} is as thread-safe as the {@link Map} that it wraps is. Normally you only
* have to consider read-only access, as the FreeMarker template language doesn't allow writing these hashes (though of
* course, Java methods called from the template can violate this rule).
*
*
* This adapter is used by {@link DefaultObjectWrapper} if its {@code useAdaptersForCollections} property is
* {@code true}, which is the default when its {@code incompatibleImprovements} property is 2.3.22 or higher.
*
* @since 2.3.22
*/
public class DefaultMapAdapter extends WrappingTemplateModel
implements TemplateHashModelEx2, AdapterTemplateModel, WrapperTemplateModel, TemplateModelWithAPISupport,
Serializable {
private final Map map;
/**
* Factory method for creating new adapter instances.
*
* @param map
* The map to adapt; can't be {@code null}.
* @param wrapper
* The {@link ObjectWrapper} used to wrap the items in the array.
*/
public static DefaultMapAdapter adapt(Map map, ObjectWrapperWithAPISupport wrapper) {
return new DefaultMapAdapter(map, wrapper);
}
private DefaultMapAdapter(Map map, ObjectWrapper wrapper) {
super(wrapper);
this.map = map;
}
@Override
public TemplateModel get(String key) throws TemplateModelException {
Object val;
try {
val = map.get(key);
} catch (ClassCastException e) {
throw new _TemplateModelException(e,
"ClassCastException while getting Map entry with String key ",
new _DelayedJQuote(key));
} catch (NullPointerException e) {
throw new _TemplateModelException(e,
"NullPointerException while getting Map entry with String key ",
new _DelayedJQuote(key));
}
if (val == null) {
// Check for Character key if this is a single-character string.
// In SortedMap-s, however, we can't do that safely, as it can cause ClassCastException.
if (key.length() == 1 && !(map instanceof SortedMap)) {
Character charKey = Character.valueOf(key.charAt(0));
try {
val = map.get(charKey);
if (val == null) {
TemplateModel wrappedNull = wrap(null);
if (wrappedNull == null || !(map.containsKey(key) || map.containsKey(charKey))) {
return null;
} else {
return wrappedNull;
}
}
} catch (ClassCastException e) {
throw new _TemplateModelException(e,
"Class casting exception while getting Map entry with Character key ",
new _DelayedJQuote(charKey));
} catch (NullPointerException e) {
throw new _TemplateModelException(e,
"NullPointerException while getting Map entry with Character key ",
new _DelayedJQuote(charKey));
}
} else { // No char key fallback was possible
TemplateModel wrappedNull = wrap(null);
if (wrappedNull == null || !map.containsKey(key)) {
return null;
} else {
return wrappedNull;
}
}
}
return wrap(val);
}
@Override
public boolean isEmpty() {
return map.isEmpty();
}
@Override
public int size() {
return map.size();
}
@Override
public TemplateCollectionModel keys() {
return new SimpleCollection(map.keySet(), getObjectWrapper());
}
@Override
public TemplateCollectionModel values() {
return new SimpleCollection(map.values(), getObjectWrapper());
}
@Override
public KeyValuePairIterator keyValuePairIterator() {
return new MapKeyValuePairIterator(map, getObjectWrapper());
}
@Override
public Object getAdaptedObject(Class hint) {
return map;
}
@Override
public Object getWrappedObject() {
return map;
}
@Override
public TemplateModel getAPI() throws TemplateModelException {
return ((ObjectWrapperWithAPISupport) getObjectWrapper()).wrapAsAPI(map);
}
}