| /* |
| * 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 freemarker.template.ObjectWrapper; |
| |
| /** |
| * Marker interface useful when used together with {@link MethodAppearanceFineTuner} and such customizer objects, to |
| * indicate that it <b>doesn't contain reference to the {@link ObjectWrapper}</b> (so beware with non-static inner |
| * classes) and can be and should be used in call introspection cache keys. This also implies that you won't |
| * create many instances of the class, rather just reuse the same (or same few) instances over and over. Furthermore, |
| * the instances must be thread-safe. The typical pattern in which this instance should be used is like this: |
| * |
| * <pre>static class MyMethodAppearanceFineTuner implements MethodAppearanceFineTuner, SingletonCustomizer { |
| * |
| * // This is the singleton: |
| * static final MyMethodAppearanceFineTuner INSTANCE = new MyMethodAppearanceFineTuner(); |
| * |
| * // Private, so it can't be constructed from outside this class. |
| * private MyMethodAppearanceFineTuner() { } |
| * |
| * @Override |
| * public void fineTuneMethodAppearance(...) { |
| * // Do something here, only using the parameters and maybe some other singletons. |
| * ... |
| * } |
| * |
| * }</pre> |
| * |
| * @since 2.3.21 |
| */ |
| public interface SingletonCustomizer { |
| |
| } |
