| /* |
| * 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.commons.collections4.functors; |
| |
| import java.lang.reflect.Constructor; |
| import java.lang.reflect.InvocationTargetException; |
| |
| import org.apache.commons.collections4.FunctorException; |
| import org.apache.commons.collections4.Transformer; |
| |
| /** |
| * Transformer implementation that creates a new object instance by reflection. |
| * <p> |
| * <b>WARNING:</b> from v4.1 onwards this class will <b>not</b> be serializable anymore |
| * in order to prevent potential remote code execution exploits. Please refer to |
| * <a href="https://issues.apache.org/jira/browse/COLLECTIONS-580">COLLECTIONS-580</a> |
| * for more details. |
| * |
| * @since 3.0 |
| * @version $Id$ |
| */ |
| public class InstantiateTransformer<T> implements Transformer<Class<? extends T>, T> { |
| |
| /** Singleton instance that uses the no arg constructor */ |
| @SuppressWarnings("rawtypes") |
| private static final Transformer NO_ARG_INSTANCE = new InstantiateTransformer<Object>(); |
| |
| /** The constructor parameter types */ |
| private final Class<?>[] iParamTypes; |
| /** The constructor arguments */ |
| private final Object[] iArgs; |
| |
| /** |
| * Get a typed no-arg instance. |
| * |
| * @param <T> the type of the objects to be created |
| * @return Transformer<Class<? extends T>, T> |
| */ |
| @SuppressWarnings("unchecked") |
| public static <T> Transformer<Class<? extends T>, T> instantiateTransformer() { |
| return NO_ARG_INSTANCE; |
| } |
| |
| /** |
| * Transformer method that performs validation. |
| * |
| * @param <T> the type of the objects to be created |
| * @param paramTypes the constructor parameter types |
| * @param args the constructor arguments |
| * @return an instantiate transformer |
| * @throws IllegalArgumentException if paramTypes does not match args |
| */ |
| public static <T> Transformer<Class<? extends T>, T> instantiateTransformer(final Class<?>[] paramTypes, |
| final Object[] args) { |
| if (((paramTypes == null) && (args != null)) |
| || ((paramTypes != null) && (args == null)) |
| || ((paramTypes != null) && (args != null) && (paramTypes.length != args.length))) { |
| throw new IllegalArgumentException("Parameter types must match the arguments"); |
| } |
| |
| if (paramTypes == null || paramTypes.length == 0) { |
| return new InstantiateTransformer<T>(); |
| } |
| return new InstantiateTransformer<T>(paramTypes, args); |
| } |
| |
| /** |
| * Constructor for no arg instance. |
| */ |
| private InstantiateTransformer() { |
| super(); |
| iParamTypes = null; |
| iArgs = null; |
| } |
| |
| /** |
| * Constructor that performs no validation. |
| * Use <code>instantiateTransformer</code> if you want that. |
| * <p> |
| * Note: from 4.0, the input parameters will be cloned |
| * |
| * @param paramTypes the constructor parameter types |
| * @param args the constructor arguments |
| */ |
| public InstantiateTransformer(final Class<?>[] paramTypes, final Object[] args) { |
| super(); |
| iParamTypes = paramTypes != null ? paramTypes.clone() : null; |
| iArgs = args != null ? args.clone() : null; |
| } |
| |
| /** |
| * Transforms the input Class object to a result by instantiation. |
| * |
| * @param input the input object to transform |
| * @return the transformed result |
| */ |
| @Override |
| public T transform(final Class<? extends T> input) { |
| try { |
| if (input == null) { |
| throw new FunctorException( |
| "InstantiateTransformer: Input object was not an instanceof Class, it was a null object"); |
| } |
| final Constructor<? extends T> con = input.getConstructor(iParamTypes); |
| return con.newInstance(iArgs); |
| } catch (final NoSuchMethodException ex) { |
| throw new FunctorException("InstantiateTransformer: The constructor must exist and be public "); |
| } catch (final InstantiationException ex) { |
| throw new FunctorException("InstantiateTransformer: InstantiationException", ex); |
| } catch (final IllegalAccessException ex) { |
| throw new FunctorException("InstantiateTransformer: Constructor must be public", ex); |
| } catch (final InvocationTargetException ex) { |
| throw new FunctorException("InstantiateTransformer: Constructor threw an exception", ex); |
| } |
| } |
| |
| } |