1 /*

     2  * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

    11  * This code is distributed in the hope that it will be useful, but WITHOUT

    12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    14  * version 2 for more details (a copy is included in the LICENSE file that

    15  * accompanied this code).

    16  *

    17  * You should have received a copy of the GNU General Public License version

    18  * 2 along with this work; if not, write to the Free Software Foundation,

    19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    20  *

    21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    22  * or visit www.oracle.com if you need additional information or have any

    23  * questions.

    24  */

    25 

    26 package javax.xml.ws.spi;

    27 

    28 import java.util.ServiceLoader;

    29 import java.util.logging.Level;

    30 import java.util.logging.Logger;

    31 

    32 /**

    33  * Shared ServiceLoader/FactoryFinder Utils shared among SAAJ, JAXB and JAXWS

    34  * Class duplicated to all those projects.

    35  *

    36  * @author Miroslav.Kos@oracle.com

    37  */

    38 class ServiceLoaderUtil {

    39 

    40     static <P, T extends Exception> P firstByServiceLoader(Class<P> spiClass,

    41                                                            Logger logger,

    42                                                            ExceptionHandler<T> handler) throws T {

    43         logger.log(Level.FINE, "Using java.util.ServiceLoader to find {0}", spiClass.getName());

    44         // service discovery

    45         try {

    46             ServiceLoader<P> serviceLoader = ServiceLoader.load(spiClass);

    47 

    48             for (P impl : serviceLoader) {

    49                 logger.fine("ServiceProvider loading Facility used; returning object [" +

    50                         impl.getClass().getName() + "]");

    51 

    52                 return impl;

    53             }

    54         } catch (Throwable t) {

    55             throw handler.createException(t, "Error while searching for service [" + spiClass.getName() + "]");

    56         }

    57         return null;

    58     }

    59 

    60     static void checkPackageAccess(String className) {

    61         // make sure that the current thread has an access to the package of the given name.

    62         SecurityManager s = System.getSecurityManager();

    63         if (s != null) {

    64             int i = className.lastIndexOf('.');

    65             if (i != -1) {

    66                 s.checkPackageAccess(className.substring(0, i));

    67             }

    68         }

    69     }

    70 

    71     static Class nullSafeLoadClass(String className, ClassLoader classLoader) throws ClassNotFoundException {

    72         if (classLoader == null) {

    73             return Class.forName(className);

    74         } else {

    75             return classLoader.loadClass(className);

    76         }

    77     }

    78 

    79     // Returns instance of required class. It checks package access (security)

    80     // unless it is defaultClassname. It means if you are trying to instantiate

    81     // default implementation (fallback), pass the class name to both first and second parameter.

    82     static <T extends Exception> Object newInstance(String className,

    83                                                     String defaultImplClassName, ClassLoader classLoader,

    84                                                     final ExceptionHandler<T> handler) throws T {

    85         try {

    86             return safeLoadClass(className, defaultImplClassName, classLoader).newInstance();

    87         } catch (ClassNotFoundException x) {

    88             throw handler.createException(x, "Provider " + className + " not found");

    89         } catch (Exception x) {

    90             throw handler.createException(x, "Provider " + className + " could not be instantiated: " + x);

    91         }

    92     }

    93 

    94     static Class safeLoadClass(String className,

    95                                String defaultImplClassName,

    96                                ClassLoader classLoader) throws ClassNotFoundException {

    97 

    98         try {

    99             checkPackageAccess(className);

   100         } catch (SecurityException se) {

   101             // anyone can access the platform default factory class without permission

   102             if (defaultImplClassName != null && defaultImplClassName.equals(className)) {

   103                 return Class.forName(className);

   104             }

   105             // not platform default implementation ...

   106             throw se;

   107         }

   108         return nullSafeLoadClass(className, classLoader);

   109     }

   110 

   111     static <T extends Exception> ClassLoader contextClassLoader(ExceptionHandler<T> exceptionHandler) throws T {

   112         try {

   113             return Thread.currentThread().getContextClassLoader();

   114         } catch (Exception x) {

   115             throw exceptionHandler.createException(x, x.toString());

   116         }

   117     }

   118 

   119     static abstract class ExceptionHandler<T extends Exception> {

   120 

   121         public abstract T createException(Throwable throwable, String message);

   122 

   123     }

   124 

   125 }