com.sun.xml.stream.buffer.ContextClassloaderLocal Maven / Gradle / Ivy
Go to download
Show more of this group Show more artifacts with this name
Show all versions of streambuffer Show documentation
Show all versions of streambuffer Show documentation
Stream based representation for XML infoset
The newest version!
/*
* Copyright (c) 2014, 2021 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 com.sun.xml.stream.buffer;
import java.security.AccessController;
import java.security.PrivilegedAction;
import java.text.MessageFormat;
import java.util.ResourceBundle;
import java.util.WeakHashMap;
/**
* Simple utility ensuring that the value is cached only in case it is non-internal implementation
*/
abstract class ContextClassloaderLocal {
private static final String FAILED_TO_CREATE_NEW_INSTANCE = "FAILED_TO_CREATE_NEW_INSTANCE";
private WeakHashMap CACHE = new WeakHashMap<>();
public V get() throws Error {
ClassLoader tccl = getContextClassLoader();
V instance = CACHE.get(tccl);
if (instance == null) {
instance = createNewInstance();
CACHE.put(tccl, instance);
}
return instance;
}
public void set(V instance) {
CACHE.put(getContextClassLoader(), instance);
}
protected abstract V initialValue() throws Exception;
private V createNewInstance() {
try {
return initialValue();
} catch (Exception e) {
throw new Error(format(FAILED_TO_CREATE_NEW_INSTANCE, getClass().getName()), e);
}
}
private static String format(String property, Object... args) {
String text = ResourceBundle.getBundle(ContextClassloaderLocal.class.getName()).getString(property);
return MessageFormat.format(text, args);
}
private static ClassLoader getContextClassLoader() {
return AccessController.doPrivileged(new PrivilegedAction() {
@Override
public ClassLoader run() {
ClassLoader cl = null;
try {
cl = Thread.currentThread().getContextClassLoader();
} catch (SecurityException ex) {
}
return cl;
}
});
}
}