| /* |
| * 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.scriptbuilder.functionloader.osgi; |
| |
| import java.io.IOException; |
| import java.net.URL; |
| import java.util.Dictionary; |
| import java.util.Enumeration; |
| import java.util.Hashtable; |
| |
| import org.jclouds.scriptbuilder.domain.OsFamily; |
| import org.jclouds.scriptbuilder.domain.ShellToken; |
| import org.jclouds.scriptbuilder.functionloader.FunctionLoader; |
| import org.jclouds.scriptbuilder.functionloader.FunctionNotFoundException; |
| import org.osgi.framework.Bundle; |
| import org.osgi.framework.BundleContext; |
| import org.osgi.framework.ServiceRegistration; |
| |
| import com.google.common.base.Charsets; |
| import com.google.common.io.Resources; |
| |
| /** |
| * A {@link FunctionLoader} which searches for functions in the {@link Bundle} resources. |
| */ |
| public class BundleFunctionLoader implements FunctionLoader { |
| |
| private final BundleContext bundleContext; |
| private ServiceRegistration registration; |
| |
| /** |
| * Constructor |
| * |
| * @param bundleContext |
| */ |
| public BundleFunctionLoader(BundleContext bundleContext) { |
| this.bundleContext = bundleContext; |
| } |
| |
| /** |
| * Starts the loader. Looks up for {@link Bundle} resources and registers itself in the service |
| * registry. It adds a property to the service which advertise all the functions found in the |
| * local resources. |
| */ |
| public void start() { |
| Bundle bundle = bundleContext.getBundle(); |
| Enumeration<?> entries = bundle.findEntries("/functions/", "*.*", false); |
| StringBuilder sb = new StringBuilder(); |
| while (entries.hasMoreElements()) { |
| URL url = (URL) entries.nextElement(); |
| String function = url.getFile(); |
| sb.append(function); |
| if (entries.hasMoreElements()) { |
| sb.append(" "); |
| } |
| } |
| String functions = sb.toString(); |
| registerFunction(functions); |
| } |
| |
| /** |
| * Unregisters itself from the service registry. |
| */ |
| public void stop() { |
| registration.unregister(); |
| } |
| |
| /** |
| * Loads the function from the {@link Bundle} resources. |
| * |
| * @param function |
| * The function name to load. |
| * @param family |
| * This operating system family of the function. |
| * @return |
| * @throws FunctionNotFoundException |
| */ |
| @Override |
| public String loadFunction(String function, OsFamily family) throws FunctionNotFoundException { |
| try { |
| return Resources.toString(bundleContext.getBundle().getResource( |
| String.format("/functions/%s.%s", function, ShellToken.SH.to(family))), Charsets.UTF_8); |
| } catch (IOException e) { |
| throw new FunctionNotFoundException(function, family, e); |
| } |
| } |
| |
| private void registerFunction(String functions) { |
| String[] className = { FunctionLoader.class.getName() }; |
| Dictionary<String, Object> dictionary = new Hashtable<String, Object>(1); |
| dictionary.put("function", functions); |
| registration = bundleContext.registerService(className, this, dictionary); |
| } |
| |
| } |