org.jboss.weld.context.cache.RequestScopedCache Maven / Gradle / Ivy
/*
* JBoss, Home of Professional Open Source
* Copyright 2010, Red Hat, Inc., and individual contributors
* by the @authors tag. See the copyright.txt in the distribution for a
* full listing of individual contributors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
* http://www.apache.org/licenses/LICENSE-2.0
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.jboss.weld.context.cache;
import java.util.LinkedList;
import java.util.List;
/**
* Caches beans over the life of a request, to allow for efficient bean lookups from proxies.
* Besides, can hold any ThreadLocals to be removed at the end of the request.
*
* @author Stuart Douglas
*/
public class RequestScopedCache {
private static final ThreadLocal> CACHE = new ThreadLocal>();
private RequestScopedCache() {
}
public static boolean isActive() {
return CACHE.get() != null;
}
private static void checkCacheForAdding(final List cache) {
if (cache == null) {
throw new IllegalStateException("Unable to add request scoped cache item when request cache is not active");
}
}
public static void addItem(final RequestScopedItem item) {
final List cache = CACHE.get();
checkCacheForAdding(cache);
cache.add(item);
}
public static boolean addItemIfActive(final RequestScopedItem item) {
final List cache = CACHE.get();
if (cache != null) {
cache.add(item);
return true;
}
return false;
}
public static boolean addItemIfActive(final ThreadLocal item) {
final List cache = CACHE.get();
if (cache != null) {
cache.add(new RequestScopedItem() {
public void invalidate() {
item.remove();
}
});
return true;
}
return false;
}
public static void beginRequest() {
// if the previous request was not ended properly for some reason, make sure it is ended now
endRequest();
CACHE.set(new LinkedList());
}
/**
* ends the request and clears the cache. This can be called before the request is over,
* in which case the cache will be unavailable for the rest of the request.
*/
public static void endRequest() {
final List result = CACHE.get();
if (result != null) {
CACHE.remove();
for (final RequestScopedItem item : result) {
item.invalidate();
}
}
}
/**
* Flushes the bean cache. The cache remains available for the rest of the request.
*/
public static void invalidate() {
if (isActive()) {
endRequest();
beginRequest();
}
}
}