| /* |
| * Copyright (c) 2010, 2011, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| /** |
| * Given an input object maps to an appropriate output object. A mapper may |
| * variously provide a mapping between types, object instances or keys and |
| * values or any other form of transformation upon the input. |
| * |
| * <p/>All mapper implementations are expected to: |
| * <ul> |
| * <li>Provide stable results such that for any {@code t} the result of two |
| * {@code map} operations are always equivalent. ie.<pre> |
| * Foo one = mapper.map(a); |
| * Foo two = mapper.map(a); |
| * |
| * assert one.equals(two) && two.equals(one); |
| * </pre></li> |
| * <li>Equivalent input objects should map to equivalent output objects. ie.<pre> |
| * assert a.equals(b); // a and b are equivalent |
| * |
| * Foo x = mapper.map(a); |
| * Foo y = mapper.map(b); |
| * |
| * assert x.equals(y); // their mapped results should be as equivalent. |
| * </pre></li> |
| * <li>The mapper should not modify the input object in any way that would |
| * change the mapping.</li> |
| * <li>When used for aggregate operations upon many elements mappers |
| * should not assume that the {@code map} operation will be called upon elements |
| * in any specific order.</li> |
| * </ul> |
| * |
| * @param <R> the type of output objects from {@code map} operation. May be the |
| * @param <T> the type of input objects provided to the {@code map} operation. |
| * same type as {@code <T>}. |
| */ |
| public interface TMapper<R, T> { |
| |
| /** |
| * Map the provided input object to an appropriate output object. |
| * |
| * @param t the input object to be mapped. |
| * @return the mapped output object. |
| */ |
| R map(T t); |
| } |