| /* |
| * 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.InvocationTargetException; |
| import java.lang.reflect.Method; |
| |
| 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 InvokerTransformer<I, O> implements Transformer<I, O> { |
| |
| /** The method name to call */ |
| private final String iMethodName; |
| /** The array of reflection parameter types */ |
| private final Class<?>[] iParamTypes; |
| /** The array of reflection arguments */ |
| private final Object[] iArgs; |
| |
| /** |
| * Gets an instance of this transformer calling a specific method with no arguments. |
| * |
| * @param <I> the input type |
| * @param <O> the output type |
| * @param methodName the method name to call |
| * @return an invoker transformer |
| * @throws NullPointerException if methodName is null |
| * @since 3.1 |
| */ |
| public static <I, O> Transformer<I, O> invokerTransformer(final String methodName) { |
| if (methodName == null) { |
| throw new NullPointerException("The method to invoke must not be null"); |
| } |
| return new InvokerTransformer<I, O>(methodName); |
| } |
| |
| /** |
| * Gets an instance of this transformer calling a specific method with specific values. |
| * |
| * @param <I> the input type |
| * @param <O> the output type |
| * @param methodName the method name to call |
| * @param paramTypes the parameter types of the method |
| * @param args the arguments to pass to the method |
| * @return an invoker transformer |
| * @throws NullPointerException if methodName is null |
| * @throws IllegalArgumentException if paramTypes does not match args |
| */ |
| public static <I, O> Transformer<I, O> invokerTransformer(final String methodName, final Class<?>[] paramTypes, |
| final Object[] args) { |
| if (methodName == null) { |
| throw new NullPointerException("The method to invoke must not be null"); |
| } |
| if (((paramTypes == null) && (args != null)) |
| || ((paramTypes != null) && (args == null)) |
| || ((paramTypes != null) && (args != null) && (paramTypes.length != args.length))) { |
| throw new IllegalArgumentException("The parameter types must match the arguments"); |
| } |
| if (paramTypes == null || paramTypes.length == 0) { |
| return new InvokerTransformer<I, O>(methodName); |
| } |
| return new InvokerTransformer<I, O>(methodName, paramTypes, args); |
| } |
| |
| /** |
| * Constructor for no arg instance. |
| * |
| * @param methodName the method to call |
| */ |
| private InvokerTransformer(final String methodName) { |
| super(); |
| iMethodName = methodName; |
| iParamTypes = null; |
| iArgs = null; |
| } |
| |
| /** |
| * Constructor that performs no validation. |
| * Use <code>invokerTransformer</code> if you want that. |
| * <p> |
| * Note: from 4.0, the input parameters will be cloned |
| * |
| * @param methodName the method to call |
| * @param paramTypes the constructor parameter types |
| * @param args the constructor arguments |
| */ |
| public InvokerTransformer(final String methodName, final Class<?>[] paramTypes, final Object[] args) { |
| super(); |
| iMethodName = methodName; |
| iParamTypes = paramTypes != null ? paramTypes.clone() : null; |
| iArgs = args != null ? args.clone() : null; |
| } |
| |
| /** |
| * Transforms the input to result by invoking a method on the input. |
| * |
| * @param input the input object to transform |
| * @return the transformed result, null if null input |
| */ |
| @Override |
| @SuppressWarnings("unchecked") |
| public O transform(final Object input) { |
| if (input == null) { |
| return null; |
| } |
| try { |
| final Class<?> cls = input.getClass(); |
| final Method method = cls.getMethod(iMethodName, iParamTypes); |
| return (O) method.invoke(input, iArgs); |
| } catch (final NoSuchMethodException ex) { |
| throw new FunctorException("InvokerTransformer: The method '" + iMethodName + "' on '" + |
| input.getClass() + "' does not exist"); |
| } catch (final IllegalAccessException ex) { |
| throw new FunctorException("InvokerTransformer: The method '" + iMethodName + "' on '" + |
| input.getClass() + "' cannot be accessed"); |
| } catch (final InvocationTargetException ex) { |
| throw new FunctorException("InvokerTransformer: The method '" + iMethodName + "' on '" + |
| input.getClass() + "' threw an exception", ex); |
| } |
| } |
| |
| } |