| /* ==================================================================== |
| 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 org.apache.poi.common; |
| |
| /** |
| * This is an alternative to the {@link Cloneable} interface without its side-effects. |
| * A class implementing Duplicatable provides a deep-copy of itself - usually this is done via a copy-constructor, |
| * which is invoked with a self-reference by the copy method. |
| * References to child objects are duplicated - references to parents are kept as-is and |
| * might need to be replaced by the parent copy operation. |
| * |
| * @see <a href="https://www.artima.com/intv/bloch.html#part13">Copy Constructor versus Cloning</a> |
| */ |
| public interface Duplicatable { |
| // Providing a generics interface Duplicatable<T extends Duplicatable<T>> pushes too many |
| // changes to the implementing classes and the benefit of providing a subtype-specific copy method |
| // is not sufficient |
| /** |
| * @return a deep copy of the implementing class / instance |
| */ |
| Duplicatable copy(); |
| } |