juzu.impl.inject.ScopeController Maven / Gradle / Ivy
/*
* Copyright 2013 eXo Platform SAS
*
* 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 juzu.impl.inject;
import juzu.Scope;
/** @author Julien Viet */
public class ScopeController {
/** . */
public static final ScopeController INSTANCE = new ScopeController();
/** . */
final ThreadLocal currentContext = new ThreadLocal();
public static void begin(ScopingContext context) throws IllegalStateException {
if (context == null) {
throw new NullPointerException();
}
if (INSTANCE.currentContext.get() != null) {
throw new IllegalStateException("Already started");
}
INSTANCE.currentContext.set(context);
}
public static void end() {
INSTANCE.currentContext.set(null);
}
private ScopeController() {
}
/**
* Obtain a scoped object.
*
* @param scope the scope
* @param key the key
* @return the scoped object or null
* @throws IllegalStateException if the scope is not active
*/
public Scoped get(Scope scope, Object key) throws IllegalStateException {
ScopingContext ctx = currentContext.get();
if (ctx == null) {
throw new IllegalStateException("Context not active");
}
if (!ctx.isActive(scope)) {
throw new IllegalStateException("Context not active");
}
return ctx.getContextualValue(scope, key);
}
/**
* Scope an object.
*
* @param scope the scope
* @param key the key
* @param scoped
* @throws IllegalStateException if the scope is not active
*/
public void put(Scope scope, Object key, Scoped scoped) throws IllegalStateException {
ScopingContext ctx = currentContext.get();
if (ctx == null) {
throw new IllegalStateException("Context not active");
}
if (!ctx.isActive(scope)) {
throw new IllegalStateException("Context not active");
}
ctx.setContextualValue(scope, key, scoped);
}
/**
* Tells if a scope is active or not.
*
* @param scope the scope
* @return true if the scope is active
*/
public boolean isActive(Scope scope) {
ScopingContext ctx = currentContext.get();
return ctx != null && ctx.isActive(scope);
}
}