Java tutorial
/* * 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.virtualbox.functions; import static com.google.common.base.Preconditions.checkNotNull; import java.io.File; import java.io.IOException; import javax.inject.Inject; import javax.inject.Named; import org.jclouds.util.Strings2; import org.jclouds.virtualbox.config.VirtualBoxConstants; import com.google.common.base.Charsets; import com.google.common.base.Supplier; import com.google.common.io.Files; /** * A supplier for vbox yaml config that reads a yaml whose path is stored under * VirtualBoxConstants.VIRTUALBOX_IMAGES_DESCRIPTOR. * * @author dralves * */ public class YamlImagesFromFileConfig implements Supplier<String> { private String yamlFilePath; @Inject public YamlImagesFromFileConfig(@Named(VirtualBoxConstants.VIRTUALBOX_IMAGES_DESCRIPTOR) String yamlFilePath) { this.yamlFilePath = yamlFilePath; } @Override public String get() { try { File yamlFile = new File(yamlFilePath); String yamlDesc = null; // if the yaml file does not exist just use default-images.yaml if (!yamlFile.exists()) { yamlDesc = Strings2.toStringAndClose(getClass().getResourceAsStream("/default-images.yaml")); } else { yamlDesc = Files.toString(yamlFile, Charsets.UTF_8); } checkNotNull(yamlDesc, "yaml descriptor"); return yamlDesc; } catch (IOException e) { throw new RuntimeException("error reading yaml file"); } } }