| /* |
| * 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.jclouds.config; |
| |
| import static com.google.common.base.Preconditions.checkNotNull; |
| import static com.google.inject.name.Names.named; |
| |
| import javax.inject.Inject; |
| |
| import com.google.common.base.Function; |
| import com.google.inject.ConfigurationException; |
| import com.google.inject.Injector; |
| import com.google.inject.Key; |
| |
| public class ValueOfConfigurationKeyOrNull implements Function<String, String> { |
| private final Injector injector; |
| |
| @Inject |
| private ValueOfConfigurationKeyOrNull(Injector injector) { |
| this.injector = checkNotNull(injector, "injector"); |
| } |
| |
| @Override |
| public String apply(String configurationKey) { |
| checkNotNull(configurationKey, "configurationKey"); |
| try { |
| return injector.getInstance(Key.get(String.class, named(configurationKey))); |
| } catch (ConfigurationException e) { |
| return null; |
| } |
| } |
| } |