freemarker.template.DefaultNonListCollectionAdapter Maven / Gradle / Ivy
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* 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.Collection;
import java.util.List;
import freemarker.core._DelayedShortClassName;
import freemarker.core._TemplateModelException;
import freemarker.ext.util.WrapperTemplateModel;
import freemarker.template.utility.ObjectWrapperWithAPISupport;
/**
* Adapts a non-{@link List} Java {@link Collection} to the corresponding {@link TemplateModel} interface(s), most
* importantly to {@link TemplateCollectionModelEx}. For {@link List}-s, use {@link DefaultListAdapter}, or else you
* lose indexed element access.
*
*
* Thread safety: A {@link DefaultNonListCollectionAdapter} is as thread-safe as the {@link Collection} that it wraps
* is. Normally you only have to consider read-only access, as the FreeMarker template language doesn't allow writing
* these collections (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, and its
* {@link DefaultObjectWrapper#setForceLegacyNonListCollections(boolean) forceLegacyNonListCollections} property is
* {@code false}, which is still not the default as of 2.3.22 (so you have to set it explicitly).
*
* @since 2.3.22
*/
public class DefaultNonListCollectionAdapter extends WrappingTemplateModel implements TemplateCollectionModelEx,
AdapterTemplateModel, WrapperTemplateModel, TemplateModelWithAPISupport, Serializable {
private final Collection collection;
/**
* Factory method for creating new adapter instances.
*
* @param collection
* The collection to adapt; can't be {@code null}.
* @param wrapper
* The {@link ObjectWrapper} used to wrap the items in the collection. Has to be
* {@link ObjectWrapperAndUnwrapper} because of planned future features.
*/
public static DefaultNonListCollectionAdapter adapt(Collection collection, ObjectWrapperWithAPISupport wrapper) {
return new DefaultNonListCollectionAdapter(collection, wrapper);
}
private DefaultNonListCollectionAdapter(Collection collection, ObjectWrapperWithAPISupport wrapper) {
super(wrapper);
this.collection = collection;
}
@Override
public TemplateModelIterator iterator() throws TemplateModelException {
return new IteratorToTemplateModelIteratorAdapter(collection.iterator(), getObjectWrapper());
}
@Override
public int size() {
return collection.size();
}
@Override
public boolean isEmpty() {
return collection.isEmpty();
}
@Override
public Object getWrappedObject() {
return collection;
}
@Override
public Object getAdaptedObject(Class hint) {
return getWrappedObject();
}
public boolean contains(TemplateModel item) throws TemplateModelException {
Object itemPojo = ((ObjectWrapperAndUnwrapper) getObjectWrapper()).unwrap(item);
try {
return collection.contains(itemPojo);
} catch (ClassCastException e) {
throw new _TemplateModelException(e,
"Failed to check if the collection contains the item. Probably the item's Java type, ",
itemPojo != null ? new _DelayedShortClassName(itemPojo.getClass()) : "Null",
", doesn't match the type of (some of) the collection items; see cause exception.");
}
}
@Override
public TemplateModel getAPI() throws TemplateModelException {
return ((ObjectWrapperWithAPISupport) getObjectWrapper()).wrapAsAPI(collection);
}
}