/*
 * Copyright (c) 2015, 2020 Oracle and/or its affiliates. All rights reserved.
 *
 * This program and the accompanying materials are made available under the
 * terms of the Eclipse Distribution License v. 1.0, which is available at
 * http://www.eclipse.org/org/documents/edl-v10.php.
 *
 * SPDX-License-Identifier: BSD-3-Clause
 */

package jakarta.xml.bind;

import java.lang.reflect.InvocationTargetException;
import java.lang.reflect.Method;
import java.util.Iterator;
import java.util.ServiceLoader;
import java.util.logging.Level;
import java.util.logging.Logger;

Shared ServiceLoader/FactoryFinder Utils shared among Jakarta SOAP with Attachments, Jakarta XML Binding and Jakarta XML Web Services. Class duplicated to all those projects.
Author:Miroslav.Kos@oracle.com
/** * Shared ServiceLoader/FactoryFinder Utils shared among Jakarta SOAP with Attachments, Jakarta XML Binding * and Jakarta XML Web Services. * Class duplicated to all those projects. * * @author Miroslav.Kos@oracle.com */
class ServiceLoaderUtil { private static final String OSGI_SERVICE_LOADER_CLASS_NAME = "org.glassfish.hk2.osgiresourcelocator.ServiceLoader"; private static final String OSGI_SERVICE_LOADER_METHOD_NAME = "lookupProviderClasses"; static <P, T extends Exception> P firstByServiceLoader(Class<P> spiClass, Logger logger, ExceptionHandler<T> handler) throws T { // service discovery try { ServiceLoader<P> serviceLoader = ServiceLoader.load(spiClass); for (P impl : serviceLoader) { logger.fine("ServiceProvider loading Facility used; returning object [" + impl.getClass().getName() + "]"); return impl; } } catch (Throwable t) { throw handler.createException(t, "Error while searching for service [" + spiClass.getName() + "]"); } return null; } static Object lookupUsingOSGiServiceLoader(String factoryId, Logger logger) { try { // Use reflection to avoid having any dependency on ServiceLoader class Class serviceClass = Class.forName(factoryId); Class target = Class.forName(OSGI_SERVICE_LOADER_CLASS_NAME); Method m = target.getMethod(OSGI_SERVICE_LOADER_METHOD_NAME, Class.class); Iterator iter = ((Iterable) m.invoke(null, serviceClass)).iterator(); if (iter.hasNext()) { Object next = iter.next(); logger.fine("Found implementation using OSGi facility; returning object [" + next.getClass().getName() + "]."); return next; } else { return null; } } catch (IllegalAccessException | InvocationTargetException | ClassNotFoundException | NoSuchMethodException ignored) { logger.log(Level.FINE, "Unable to find from OSGi: [" + factoryId + "]", ignored); return null; } } static void checkPackageAccess(String className) { // make sure that the current thread has an access to the package of the given name. SecurityManager s = System.getSecurityManager(); if (s != null) { int i = className.lastIndexOf('.'); if (i != -1) { s.checkPackageAccess(className.substring(0, i)); } } } static Class nullSafeLoadClass(String className, ClassLoader classLoader) throws ClassNotFoundException { if (classLoader == null) { return Class.forName(className); } else { return classLoader.loadClass(className); } } // Returns instance of required class. It checks package access (security) // unless it is defaultClassname. It means if you are trying to instantiate // default implementation (fallback), pass the class name to both first and second parameter. static <T extends Exception> Object newInstance(String className, String defaultImplClassName, final ExceptionHandler<T> handler) throws T { try { return safeLoadClass(className, defaultImplClassName, contextClassLoader(handler)).newInstance(); } catch (ClassNotFoundException x) { throw handler.createException(x, "Provider " + className + " not found"); } catch (Exception x) { throw handler.createException(x, "Provider " + className + " could not be instantiated: " + x); } } static Class safeLoadClass(String className, String defaultImplClassName, ClassLoader classLoader) throws ClassNotFoundException { try { checkPackageAccess(className); } catch (SecurityException se) { // anyone can access the platform default factory class without permission if (defaultImplClassName != null && defaultImplClassName.equals(className)) { return Class.forName(className); } // not platform default implementation ... throw se; } return nullSafeLoadClass(className, classLoader); } static ClassLoader contextClassLoader(ExceptionHandler exceptionHandler) throws Exception { try { return Thread.currentThread().getContextClassLoader(); } catch (Exception x) { throw exceptionHandler.createException(x, x.toString()); } } static abstract class ExceptionHandler<T extends Exception> { public abstract T createException(Throwable throwable, String message); } }