001// *************************************************************************************************************************** 002// * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file * 003// * distributed with this work for additional information regarding copyright ownership. The ASF licenses this file * 004// * to you under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance * 005// * with the License. You may obtain a copy of the License at * 006// * * 007// * http://www.apache.org/licenses/LICENSE-2.0 * 008// * * 009// * Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an * 010// * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the * 011// * specific language governing permissions and limitations under the License. * 012// *************************************************************************************************************************** 013package org.apache.juneau.transform; 014 015import static org.apache.juneau.internal.ClassUtils.*; 016 017import java.lang.reflect.*; 018import java.util.*; 019 020import org.apache.juneau.*; 021import org.apache.juneau.annotation.*; 022import org.apache.juneau.parser.*; 023import org.apache.juneau.serializer.*; 024 025/** 026 * Specialized {@link PojoSwap} for {@link Surrogate} classes. 027 * 028 * @param <T> The class type that this transform applies to. 029 * @param <F> The transformed class type. 030 */ 031public class SurrogateSwap<T,F> extends PojoSwap<T,F> { 032 033 private Constructor<F> constructor; // public F(T t); 034 private Method unswapMethod; // public T build(); 035 036 /** 037 * Constructor. 038 * 039 * @param forClass The normal class. 040 * @param constructor The constructor on the surrogate class that takes the normal class as a parameter. 041 * @param unswapMethod The static method that converts surrogate objects into normal objects. 042 */ 043 protected SurrogateSwap(Class<T> forClass, Constructor<F> constructor, Method unswapMethod) { 044 super(forClass, constructor.getDeclaringClass()); 045 this.constructor = constructor; 046 this.unswapMethod = unswapMethod; 047 } 048 049 /** 050 * Given the specified surrogate class, return the list of POJO swaps. 051 * 052 * <p> 053 * A transform is returned for each public 1-arg constructor found. 054 * Returns an empty list if no public 1-arg constructors are found. 055 * 056 * @param c The surrogate class. 057 * @return The list of POJO swaps that apply to this class. 058 */ 059 @SuppressWarnings({"unchecked", "rawtypes"}) 060 public static List<SurrogateSwap<?,?>> findPojoSwaps(Class<?> c) { 061 List<SurrogateSwap<?,?>> l = new LinkedList<>(); 062 for (Constructor<?> cc : c.getConstructors()) { 063 Class<?>[] pt = cc.getParameterTypes(); 064 if (cc.getAnnotation(BeanIgnore.class) == null && hasNumArgs(cc, 1) && isPublic(cc) && pt[0] != c.getDeclaringClass()) { 065 // Find the unswap method if there is one. 066 Method unswapMethod = null; 067 for (Method m : c.getMethods()) { 068 if (pt[0].equals(m.getReturnType()) && isPublic(m)) 069 unswapMethod = m; 070 } 071 072 l.add(new SurrogateSwap(pt[0], cc, unswapMethod)); 073 } 074 } 075 return l; 076 } 077 078 @Override /* PojoSwap */ 079 public F swap(BeanSession session, T o) throws SerializeException { 080 try { 081 return constructor.newInstance(o); 082 } catch (Exception e) { 083 throw new SerializeException(e); 084 } 085 } 086 087 @Override /* PojoSwap */ 088 @SuppressWarnings("unchecked") 089 public T unswap(BeanSession session, F f, ClassMeta<?> hint) throws ParseException { 090 if (unswapMethod == null) 091 throw new ParseException("unswap() method not implement on surrogate class ''{1}''", 092 f.getClass().getName(), getNormalClass().getName()); 093 try { 094 return (T)unswapMethod.invoke(f); 095 } catch (Exception e) { 096 throw new ParseException((Throwable)e); 097 } 098 } 099}