Thu, 31 Aug 2017 15:18:52 +0800
merge
aoqi@0 | 1 | /* |
aoqi@0 | 2 | * Copyright (c) 2014, Oracle and/or its affiliates. All rights reserved. |
aoqi@0 | 3 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
aoqi@0 | 4 | * |
aoqi@0 | 5 | * This code is free software; you can redistribute it and/or modify it |
aoqi@0 | 6 | * under the terms of the GNU General Public License version 2 only, as |
aoqi@0 | 7 | * published by the Free Software Foundation. Oracle designates this |
aoqi@0 | 8 | * particular file as subject to the "Classpath" exception as provided |
aoqi@0 | 9 | * by Oracle in the LICENSE file that accompanied this code. |
aoqi@0 | 10 | * |
aoqi@0 | 11 | * This code is distributed in the hope that it will be useful, but WITHOUT |
aoqi@0 | 12 | * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
aoqi@0 | 13 | * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
aoqi@0 | 14 | * version 2 for more details (a copy is included in the LICENSE file that |
aoqi@0 | 15 | * accompanied this code). |
aoqi@0 | 16 | * |
aoqi@0 | 17 | * You should have received a copy of the GNU General Public License version |
aoqi@0 | 18 | * 2 along with this work; if not, write to the Free Software Foundation, |
aoqi@0 | 19 | * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
aoqi@0 | 20 | * |
aoqi@0 | 21 | * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
aoqi@0 | 22 | * or visit www.oracle.com if you need additional information or have any |
aoqi@0 | 23 | * questions. |
aoqi@0 | 24 | */ |
aoqi@0 | 25 | |
aoqi@0 | 26 | package com.sun.xml.internal.xsom.util; |
aoqi@0 | 27 | |
aoqi@0 | 28 | import java.security.AccessController; |
aoqi@0 | 29 | import java.security.PrivilegedAction; |
aoqi@0 | 30 | import java.text.MessageFormat; |
aoqi@0 | 31 | import java.util.ResourceBundle; |
aoqi@0 | 32 | import java.util.WeakHashMap; |
aoqi@0 | 33 | |
aoqi@0 | 34 | /** |
aoqi@0 | 35 | * Simple utility ensuring that the value is cached only in case it is non-internal implementation |
aoqi@0 | 36 | */ |
aoqi@0 | 37 | abstract class ContextClassloaderLocal<V> { |
aoqi@0 | 38 | |
aoqi@0 | 39 | private static final String FAILED_TO_CREATE_NEW_INSTANCE = "FAILED_TO_CREATE_NEW_INSTANCE"; |
aoqi@0 | 40 | |
aoqi@0 | 41 | private WeakHashMap<ClassLoader, V> CACHE = new WeakHashMap<ClassLoader, V>(); |
aoqi@0 | 42 | |
aoqi@0 | 43 | public V get() throws Error { |
aoqi@0 | 44 | ClassLoader tccl = getContextClassLoader(); |
aoqi@0 | 45 | V instance = CACHE.get(tccl); |
aoqi@0 | 46 | if (instance == null) { |
aoqi@0 | 47 | instance = createNewInstance(); |
aoqi@0 | 48 | CACHE.put(tccl, instance); |
aoqi@0 | 49 | } |
aoqi@0 | 50 | return instance; |
aoqi@0 | 51 | } |
aoqi@0 | 52 | |
aoqi@0 | 53 | public void set(V instance) { |
aoqi@0 | 54 | CACHE.put(getContextClassLoader(), instance); |
aoqi@0 | 55 | } |
aoqi@0 | 56 | |
aoqi@0 | 57 | protected abstract V initialValue() throws Exception; |
aoqi@0 | 58 | |
aoqi@0 | 59 | private V createNewInstance() { |
aoqi@0 | 60 | try { |
aoqi@0 | 61 | return initialValue(); |
aoqi@0 | 62 | } catch (Exception e) { |
aoqi@0 | 63 | throw new Error(format(FAILED_TO_CREATE_NEW_INSTANCE, getClass().getName()), e); |
aoqi@0 | 64 | } |
aoqi@0 | 65 | } |
aoqi@0 | 66 | |
aoqi@0 | 67 | private static String format(String property, Object... args) { |
aoqi@0 | 68 | String text = ResourceBundle.getBundle(ContextClassloaderLocal.class.getName()).getString(property); |
aoqi@0 | 69 | return MessageFormat.format(text, args); |
aoqi@0 | 70 | } |
aoqi@0 | 71 | |
aoqi@0 | 72 | private static ClassLoader getContextClassLoader() { |
aoqi@0 | 73 | return (ClassLoader) |
aoqi@0 | 74 | AccessController.doPrivileged(new PrivilegedAction() { |
aoqi@0 | 75 | public Object run() { |
aoqi@0 | 76 | ClassLoader cl = null; |
aoqi@0 | 77 | try { |
aoqi@0 | 78 | cl = Thread.currentThread().getContextClassLoader(); |
aoqi@0 | 79 | } catch (SecurityException ex) { |
aoqi@0 | 80 | } |
aoqi@0 | 81 | return cl; |
aoqi@0 | 82 | } |
aoqi@0 | 83 | }); |
aoqi@0 | 84 | } |
aoqi@0 | 85 | } |
aoqi@0 | 86 |