| 1 | /** |
| 2 | * Licensed to jclouds, Inc. (jclouds) under one or more |
| 3 | * contributor license agreements. See the NOTICE file |
| 4 | * distributed with this work for additional information |
| 5 | * regarding copyright ownership. jclouds licenses this file |
| 6 | * to you under the Apache License, Version 2.0 (the |
| 7 | * "License"); you may not use this file except in compliance |
| 8 | * with the License. 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, |
| 13 | * software distributed under the License is distributed on an |
| 14 | * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| 15 | * KIND, either express or implied. See the License for the |
| 16 | * specific language governing permissions and limitations |
| 17 | * under the License. |
| 18 | */ |
| 19 | package org.jclouds.collect; |
| 20 | |
| 21 | import static com.google.common.base.Preconditions.checkNotNull; |
| 22 | |
| 23 | import java.util.NoSuchElementException; |
| 24 | import java.util.Set; |
| 25 | |
| 26 | import javax.annotation.Resource; |
| 27 | import javax.inject.Inject; |
| 28 | import javax.inject.Singleton; |
| 29 | |
| 30 | import org.jclouds.logging.Logger; |
| 31 | |
| 32 | import com.google.common.base.Function; |
| 33 | import com.google.common.base.Predicate; |
| 34 | import com.google.common.base.Supplier; |
| 35 | import com.google.common.collect.Iterables; |
| 36 | |
| 37 | /** |
| 38 | * @author Adrian Cole |
| 39 | */ |
| 40 | @Singleton |
| 41 | public abstract class FindResourceInSet<F, T> implements Function<F, T> { |
| 42 | @Resource |
| 43 | protected Logger logger = Logger.NULL; |
| 44 | |
| 45 | private final Supplier<Set<? extends T>> set; |
| 46 | |
| 47 | @Inject |
| 48 | public FindResourceInSet(@Memoized Supplier<Set<? extends T>> set) { |
| 49 | this.set = checkNotNull(set, "set"); |
| 50 | } |
| 51 | |
| 52 | public abstract boolean matches(F from, T input); |
| 53 | |
| 54 | public T apply(final F from) { |
| 55 | try { |
| 56 | return Iterables.find(set.get(), new Predicate<T>() { |
| 57 | |
| 58 | @Override |
| 59 | public boolean apply(T input) { |
| 60 | return matches(from, input); |
| 61 | } |
| 62 | |
| 63 | }); |
| 64 | } catch (NoSuchElementException e) { |
| 65 | logger.trace("could not find a match in set for %s", from); |
| 66 | } |
| 67 | return null; |
| 68 | } |
| 69 | } |