1 /* 2 * Copyright (c) 2014, 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 com.sun.xml.internal.ws.util.xml; 27 28 import java.security.AccessController; 29 import java.security.PrivilegedAction; 30 import java.text.MessageFormat; 31 import java.util.ResourceBundle; 32 import java.util.WeakHashMap; 33 34 /** 35 * Simple utility ensuring that the value is cached only in case it is non-internal implementation 36 */ 37 abstract class ContextClassloaderLocal<V> { 38 39 private static final String FAILED_TO_CREATE_NEW_INSTANCE = "FAILED_TO_CREATE_NEW_INSTANCE"; 40 41 private WeakHashMap<ClassLoader, V> CACHE = new WeakHashMap<ClassLoader, V>(); 42 43 public V get() throws Error { 44 ClassLoader tccl = getContextClassLoader(); 45 V instance = CACHE.get(tccl); 46 if (instance == null) { 47 instance = createNewInstance(); 48 CACHE.put(tccl, instance); 49 } 50 return instance; 51 } 52 53 public void set(V instance) { 54 CACHE.put(getContextClassLoader(), instance); 55 } 56 57 protected abstract V initialValue() throws Exception; 58 59 private V createNewInstance() { 60 try { 61 return initialValue(); 62 } catch (Exception e) { 63 throw new Error(format(FAILED_TO_CREATE_NEW_INSTANCE, getClass().getName()), e); 64 } 65 } 66 67 private static String format(String property, Object... args) { 68 String text = ResourceBundle.getBundle(ContextClassloaderLocal.class.getName()).getString(property); 69 return MessageFormat.format(text, args); 70 } 71 72 private static ClassLoader getContextClassLoader() { 73 return (ClassLoader) 74 AccessController.doPrivileged(new PrivilegedAction() { 75 public Object run() { 76 ClassLoader cl = null; 77 try { 78 cl = Thread.currentThread().getContextClassLoader(); 79 } catch (SecurityException ex) { 80 } 81 return cl; 82 } 83 }); 84 } 85 }