1 /* 2 * Licensed to the Apache Software Foundation (ASF) under one or more 3 * contributor license agreements. See the NOTICE file distributed with 4 * this work for additional information regarding copyright ownership. 5 * The ASF licenses this file to You under the Apache License, Version 2.0 6 * (the "License"); you may not use this file except in compliance with 7 * the License. You may obtain a copy of the License at 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 */ 17 package org.apache.commons.collections4.functors; 18 19 import org.apache.commons.collections4.Closure; 20 import org.apache.commons.collections4.FunctorException; 21 22 /** 23 * {@link Closure} that catches any checked exception and re-throws it as a 24 * {@link FunctorException} runtime exception. Example usage: 25 * 26 * <pre> 27 * // Create a catch and re-throw closure via anonymous subclass 28 * CatchAndRethrowClosure<String> writer = new ThrowingClosure() { 29 * private java.io.Writer out = // some writer 30 * 31 * protected void executeAndThrow(String input) throws IOException { 32 * out.write(input); // throwing of IOException allowed 33 * } 34 * }; 35 * 36 * // use catch and re-throw closure 37 * java.util.List<String> strList = // some list 38 * try { 39 * CollectionUtils.forAllDo(strList, writer); 40 * } catch (FunctorException ex) { 41 * Throwable originalError = ex.getCause(); 42 * // handle error 43 * } 44 * </pre> 45 * 46 * @since 4.0 47 */ 48 public abstract class CatchAndRethrowClosure<E> implements Closure<E> { 49 50 /** 51 * Execute this closure on the specified input object. 52 * 53 * @param input the input to execute on 54 * @throws FunctorException (runtime) if the closure execution resulted in a 55 * checked exception. 56 */ 57 @Override 58 public void execute(final E input) { 59 try { 60 executeAndThrow(input); 61 } catch (final RuntimeException ex) { 62 throw ex; 63 } catch (final Throwable t) { 64 throw new FunctorException(t); 65 } 66 } 67 68 /** 69 * Execute this closure on the specified input object. 70 * 71 * @param input the input to execute on 72 * @throws Throwable if the closure execution resulted in a checked 73 * exception. 74 */ 75 protected abstract void executeAndThrow(E input) throws Throwable; 76 }