| /* |
| * 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.apache.nifi.registry.extension; |
| |
| import org.apache.commons.lang3.StringUtils; |
| import org.apache.nifi.registry.hook.EventHookProvider; |
| import org.apache.nifi.registry.security.authentication.IdentityProvider; |
| import org.apache.nifi.registry.security.authorization.AccessPolicyProvider; |
| import org.apache.nifi.registry.security.authorization.Authorizer; |
| import org.apache.nifi.registry.security.authorization.UserGroupProvider; |
| import org.apache.nifi.registry.flow.FlowPersistenceProvider; |
| import org.apache.nifi.registry.properties.NiFiRegistryProperties; |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| import org.springframework.beans.factory.annotation.Autowired; |
| import org.springframework.stereotype.Component; |
| |
| import javax.annotation.PostConstruct; |
| import java.io.File; |
| import java.net.MalformedURLException; |
| import java.net.URL; |
| import java.net.URLClassLoader; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.HashMap; |
| import java.util.LinkedList; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.ServiceLoader; |
| import java.util.Set; |
| import java.util.concurrent.atomic.AtomicBoolean; |
| |
| @Component |
| public class ExtensionManager { |
| |
| static final Logger LOGGER = LoggerFactory.getLogger(ExtensionManager.class); |
| |
| private static final List<Class> EXTENSION_CLASSES; |
| static { |
| final List<Class> classes = new ArrayList<>(); |
| classes.add(FlowPersistenceProvider.class); |
| classes.add(UserGroupProvider.class); |
| classes.add(AccessPolicyProvider.class); |
| classes.add(Authorizer.class); |
| classes.add(IdentityProvider.class); |
| classes.add(EventHookProvider.class); |
| classes.add(ExtensionBundlePersistenceProvider.class); |
| EXTENSION_CLASSES = Collections.unmodifiableList(classes); |
| } |
| |
| private final NiFiRegistryProperties properties; |
| private final Map<String,ExtensionClassLoader> classLoaderMap = new HashMap<>(); |
| private final AtomicBoolean loaded = new AtomicBoolean(false); |
| |
| @Autowired |
| public ExtensionManager(final NiFiRegistryProperties properties) { |
| this.properties = properties; |
| } |
| |
| @PostConstruct |
| public synchronized void discoverExtensions() { |
| if (!loaded.get()) { |
| // get the list of class loaders to consider |
| final List<ExtensionClassLoader> classLoaders = getClassLoaders(); |
| |
| // for each class loader, attempt to load each extension class using the ServiceLoader |
| for (final ExtensionClassLoader extensionClassLoader : classLoaders) { |
| for (final Class extensionClass : EXTENSION_CLASSES) { |
| loadExtensions(extensionClass, extensionClassLoader); |
| } |
| } |
| |
| loaded.set(true); |
| } |
| } |
| |
| public ClassLoader getExtensionClassLoader(final String canonicalClassName) { |
| if (StringUtils.isBlank(canonicalClassName)) { |
| throw new IllegalArgumentException("Class name can not be null"); |
| } |
| |
| return classLoaderMap.get(canonicalClassName); |
| } |
| |
| /** |
| * Loads implementations of the given extension class from the given class loader. |
| * |
| * @param extensionClass the extension/service class |
| * @param extensionClassLoader the class loader to search |
| */ |
| private void loadExtensions(final Class extensionClass, final ExtensionClassLoader extensionClassLoader) { |
| final ServiceLoader<?> serviceLoader = ServiceLoader.load(extensionClass, extensionClassLoader); |
| for (final Object o : serviceLoader) { |
| final String extensionClassName = o.getClass().getCanonicalName(); |
| if (classLoaderMap.containsKey(extensionClassName)) { |
| final String currDir = extensionClassLoader.getRootDir(); |
| final String existingDir = classLoaderMap.get(extensionClassName).getRootDir(); |
| LOGGER.warn("Skipping {} from {} which was already found in {}", new Object[]{extensionClassName, currDir, existingDir}); |
| } else { |
| classLoaderMap.put(o.getClass().getCanonicalName(), extensionClassLoader); |
| } |
| } |
| } |
| |
| /** |
| * Gets all of the class loaders to consider for loading extensions. |
| * |
| * Includes the class loader of the web-app running the framework, plus a class loader for each additional |
| * directory specified in nifi-registry.properties. |
| * |
| * @return a list of extension class loaders |
| */ |
| private List<ExtensionClassLoader> getClassLoaders() { |
| final List<ExtensionClassLoader> classLoaders = new ArrayList<>(); |
| |
| // start with the class loader that loaded ExtensionManager, should be WebAppClassLoader for API WAR |
| final ExtensionClassLoader frameworkClassLoader = new ExtensionClassLoader("web-api", new URL[0], this.getClass().getClassLoader()); |
| classLoaders.add(frameworkClassLoader); |
| |
| // we want to use the system class loader as the parent of the extension class loaders |
| ClassLoader systemClassLoader = FlowPersistenceProvider.class.getClassLoader(); |
| |
| // add a class loader for each extension dir |
| final Set<String> extensionDirs = properties.getExtensionsDirs(); |
| for (final String dir : extensionDirs) { |
| if (!StringUtils.isBlank(dir)) { |
| final ExtensionClassLoader classLoader = createClassLoader(dir, systemClassLoader); |
| if (classLoader != null) { |
| classLoaders.add(classLoader); |
| } |
| } |
| } |
| |
| return classLoaders; |
| } |
| |
| /** |
| * Creates a class loader for the given directory of resources. |
| * |
| * @param dir the dir of resources to add to the class loader |
| * @param parentClassLoader the parent class loader |
| * @return a class loader including all of the resources in the given dir, with the specified parent class loader |
| */ |
| private ExtensionClassLoader createClassLoader(final String dir, final ClassLoader parentClassLoader) { |
| final File dirFile = new File(dir); |
| |
| if (!dirFile.exists()) { |
| LOGGER.warn("Skipping extension directory that does not exist: " + dir); |
| return null; |
| } |
| |
| if (!dirFile.canRead()) { |
| LOGGER.warn("Skipping extension directory that can not be read: " + dir); |
| return null; |
| } |
| |
| final List<URL> resources = new LinkedList<>(); |
| |
| try { |
| resources.add(dirFile.toURI().toURL()); |
| } catch (final MalformedURLException mfe) { |
| LOGGER.warn("Unable to add {} to classpath due to {}", |
| new Object[]{ dirFile.getAbsolutePath(), mfe.getMessage()}, mfe); |
| } |
| |
| if (dirFile.isDirectory()) { |
| final File[] files = dirFile.listFiles(); |
| if (files != null) { |
| for (final File resource : files) { |
| if (resource.isDirectory()) { |
| LOGGER.warn("Recursive directories are not supported, skipping " + resource.getAbsolutePath()); |
| } else { |
| try { |
| resources.add(resource.toURI().toURL()); |
| } catch (final MalformedURLException mfe) { |
| LOGGER.warn("Unable to add {} to classpath due to {}", |
| new Object[]{ resource.getAbsolutePath(), mfe.getMessage()}, mfe); |
| } |
| } |
| } |
| } |
| } |
| |
| final URL[] urls = resources.toArray(new URL[resources.size()]); |
| return new ExtensionClassLoader(dir, urls, parentClassLoader); |
| } |
| |
| /** |
| * Extend URLClassLoader to keep track of the root directory. |
| */ |
| private static class ExtensionClassLoader extends URLClassLoader { |
| |
| private final String rootDir; |
| |
| public ExtensionClassLoader(final String rootDir, final URL[] urls, final ClassLoader parent) { |
| super(urls, parent); |
| this.rootDir = rootDir; |
| } |
| |
| public String getRootDir() { |
| return rootDir; |
| } |
| } |
| } |