/*
* 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.lang.ref.
ReferenceQueue;
import java.lang.ref.
WeakReference;
import java.util.
Map;
import java.util.
WeakHashMap;
import freemarker.ext.beans.
BeansWrapperBuilder;
import freemarker.ext.beans.
_BeansAPI;
/**
* Gets/creates a {@link DefaultObjectWrapper} singleton instance that's already configured as specified in the
* properties of this object; this is recommended over using the {@link DefaultObjectWrapper} constructors. The returned
* instance can't be further configured (it's write protected).
*
* <p>See {@link BeansWrapperBuilder} for more info, as that works identically.
*
* @since 2.3.21
*/
public class
DefaultObjectWrapperBuilder extends
DefaultObjectWrapperConfiguration {
private final static
Map<
ClassLoader,
Map<
DefaultObjectWrapperConfiguration,
WeakReference<
DefaultObjectWrapper>>>
INSTANCE_CACHE = new
WeakHashMap<
ClassLoader,
Map<
DefaultObjectWrapperConfiguration,
WeakReference<
DefaultObjectWrapper>>>();
private final static
ReferenceQueue<
DefaultObjectWrapper>
INSTANCE_CACHE_REF_QUEUE
= new
ReferenceQueue<
DefaultObjectWrapper>();
/**
* Creates a builder that creates a {@link DefaultObjectWrapper} with the given {@code incompatibleImprovements};
* using at least 2.3.22 is highly recommended. See {@link DefaultObjectWrapper#DefaultObjectWrapper(Version)} for
* more information about the impact of {@code incompatibleImprovements} values.
*/
public
DefaultObjectWrapperBuilder(
Version incompatibleImprovements) {
super(
incompatibleImprovements);
}
/** For unit testing only */
static void
clearInstanceCache() {
synchronized (
INSTANCE_CACHE) {
INSTANCE_CACHE.
clear();
}
}
/**
* Returns a {@link DefaultObjectWrapper} instance that matches the settings of this builder. This will be possibly
* a singleton that is also in use elsewhere.
*/
public
DefaultObjectWrapper build() {
return
_BeansAPI.
getBeansWrapperSubclassSingleton(
this,
INSTANCE_CACHE,
INSTANCE_CACHE_REF_QUEUE,
DefaultObjectWrapperFactory.
INSTANCE);
}
private static class
DefaultObjectWrapperFactory
implements
_BeansAPI.
_BeansWrapperSubclassFactory<
DefaultObjectWrapper,
DefaultObjectWrapperConfiguration> {
private static final
DefaultObjectWrapperFactory INSTANCE = new
DefaultObjectWrapperFactory();
public
DefaultObjectWrapper create(
DefaultObjectWrapperConfiguration bwConf) {
return new
DefaultObjectWrapper(
bwConf, true);
}
}
}