org.jboss.el.cache.FactoryFinderCache Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source.
* Copyright 2012, Red Hat, Inc., and individual contributors
* as indicated by the @author tags. See the copyright.txt file in the
* distribution for a full listing of individual contributors.
*
* This is free software; you can redistribute it and/or modify it
* under the terms of the GNU Lesser General Public License as
* published by the Free Software Foundation; either version 2.1 of
* the License, or (at your option) any later version.
*
* This software is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this software; if not, write to the Free
* Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
* 02110-1301 USA, or see the FSF site: http://www.fsf.org.
*/
package org.jboss.el.cache;
import java.io.BufferedReader;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.util.Iterator;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
/**
* @author Stuart Douglas
*/
public class FactoryFinderCache {
private static final Map CLASS_CACHE = new ConcurrentHashMap();
/**
* Called by the container at deployment time to set the name of a given factory, to remove the need for the
* implementation to look it up on every call.
*
* @param classLoader The deployments class loader
* @param factoryId The type of factory that is being recorded (at this stage only javax.el.ExpressionFactory has any effect
* @param factoryClassName The name of the factory class that is present in the deployment, or null if none is present
*/
public static void addCacheEntry(final ClassLoader classLoader, final String factoryId, final String factoryClassName) {
if (factoryClassName == null) {
CLASS_CACHE.put(new CacheKey(classLoader, factoryId), "");
} else {
CLASS_CACHE.put(new CacheKey(classLoader, factoryId), factoryClassName);
}
}
/**
* This should be called by the container on undeploy to remove all references to the given class loader
* from the cache.
*
* @param classLoader The class loader to remove
*/
public static void clearClassLoader(final ClassLoader classLoader) {
final Iterator> it = CLASS_CACHE.entrySet().iterator();
while (it.hasNext()) {
final CacheKey key = it.next().getKey();
if (key.loader == classLoader) {
it.remove();
}
}
}
public static String loadImplementationClassName(final String factoryId, final ClassLoader classLoader) {
final Map classCache = CLASS_CACHE;
if (classCache != null) {
final String value = classCache.get(new CacheKey(classLoader, factoryId));
if (value != null) {
if (value.equals("")) {
return null;
}
return value;
}
}
String serviceId = "META-INF/services/" + factoryId;
// try to find services in CLASSPATH
try {
InputStream is = null;
if (classLoader == null) {
is = ClassLoader.getSystemResourceAsStream(serviceId);
} else {
is = classLoader.getResourceAsStream(serviceId);
}
if (is != null) {
BufferedReader rd =
new BufferedReader(new InputStreamReader(is, "UTF-8"));
String factoryClassName = rd.readLine();
rd.close();
if (factoryClassName != null &&
!"".equals(factoryClassName)) {
if (classCache != null) {
classCache.put(new CacheKey(classLoader, factoryId), factoryClassName);
}
return factoryClassName;
}
}
} catch (Exception ex) {
}
if (classCache != null) {
classCache.put(new CacheKey(classLoader, factoryId), "");
}
return null;
}
private static class CacheKey {
private final ClassLoader loader;
private final String className;
private CacheKey(final ClassLoader loader, final String className) {
this.loader = loader;
this.className = className;
}
@Override
public boolean equals(final Object o) {
if (this == o) return true;
if (o == null || getClass() != o.getClass()) return false;
final CacheKey cacheKey = (CacheKey) o;
if (className != null ? !className.equals(cacheKey.className) : cacheKey.className != null) return false;
if (loader != null ? !loader.equals(cacheKey.loader) : cacheKey.loader != null) return false;
return true;
}
@Override
public int hashCode() {
int result = loader != null ? loader.hashCode() : 0;
result = 31 * result + (className != null ? className.hashCode() : 0);
return result;
}
}
}