| 1 | /** |
| 2 | * |
| 3 | * Copyright (C) 2011 Cloud Conscious, LLC. <info@cloudconscious.com> |
| 4 | * |
| 5 | * ==================================================================== |
| 6 | * Licensed under the Apache License, Version 2.0 (the "License"); |
| 7 | * you may not use this file except in compliance with the License. |
| 8 | * You may obtain a copy of the License at |
| 9 | * |
| 10 | * http://www.apache.org/licenses/LICENSE-2.0 |
| 11 | * |
| 12 | * Unless required by applicable law or agreed to in writing, software |
| 13 | * distributed under the License is distributed on an "AS IS" BASIS, |
| 14 | * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 15 | * See the License for the specific language governing permissions and |
| 16 | * limitations under the License. |
| 17 | * ==================================================================== |
| 18 | */ |
| 19 | package org.jclouds.functions; |
| 20 | |
| 21 | import static com.google.common.base.Preconditions.checkNotNull; |
| 22 | |
| 23 | import java.util.List; |
| 24 | |
| 25 | import javax.annotation.Nullable; |
| 26 | |
| 27 | import org.jclouds.util.Throwables2; |
| 28 | |
| 29 | import com.google.common.base.Function; |
| 30 | import com.google.common.base.Throwables; |
| 31 | import com.google.common.collect.Iterables; |
| 32 | |
| 33 | /** |
| 34 | * |
| 35 | * @author Adrian Cole |
| 36 | */ |
| 37 | public class ExceptionToValueOrPropagate<E extends Exception, T> implements Function<Exception, T> { |
| 38 | |
| 39 | private final Class<E> matchingClass; |
| 40 | private final T value; |
| 41 | |
| 42 | public ExceptionToValueOrPropagate(Class<E> matchingClass, @Nullable T value) { |
| 43 | this.matchingClass = checkNotNull(matchingClass, "matchingClass"); |
| 44 | this.value = value; |
| 45 | } |
| 46 | |
| 47 | @SuppressWarnings("unchecked") |
| 48 | @Override |
| 49 | public T apply(Exception from) { |
| 50 | checkNotNull(from, "exception"); |
| 51 | List<Throwable> throwables = Throwables.getCausalChain(from); |
| 52 | Iterable<E> matchingThrowables = Iterables.filter(throwables, matchingClass); |
| 53 | if (Iterables.size(matchingThrowables) >= 1) |
| 54 | return value; |
| 55 | return (T) Throwables2.propagateOrNull(from); |
| 56 | } |
| 57 | |
| 58 | } |