content: package act.util;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2017 ActFramework
   * %%
   * 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.
   * #L%
   */
  
  import act.Destroyable;
  import act.handler.builtin.controller.RequestHandlerProxy;
  
  import java.lang.annotation.Annotation;
  import java.util.ArrayList;
  import java.util.List;
  import javax.enterprise.context.ApplicationScoped;
  import javax.enterprise.context.NormalScope;
  import javax.enterprise.context.RequestScoped;
  import javax.enterprise.context.SessionScoped;
  
  public abstract class DestroyableBase implements Destroyable {
  
      private volatile boolean destroyed;
  
      private List<Destroyable> subResources = new ArrayList<>();
  
      private volatile Class<? extends Annotation> scope;
  
      public DestroyableBase() {}
  
      @Override
      public final void destroy() {
          if (isDestroyed()) {
              return;
          }
          destroyed = true;
          if (!subResources.isEmpty()) {
              Destroyable.Util.destroyAll(subResources, scope());
          }
          releaseResources();
      }
  
      @Override
      public final boolean isDestroyed() {
          return destroyed;
      }
  
      /**
       * Recover the destroy state. Use this API with cautious
       */
      protected void reload() {
          RequestHandlerProxy.releaseGlobalResources();
          destroyed = false;
      }
  
      protected void releaseResources() {}
  
      public Class<? extends Annotation> scope() {
          if (null == scope) {
              synchronized (this) {
                  if (null == scope) {
                      Class<?> c = getClass();
                      if (c.isAnnotationPresent(RequestScoped.class)) {
                          scope = RequestScoped.class;
                      } else if (c.isAnnotationPresent(SessionScoped.class)) {
                          scope = SessionScoped.class;
                      } else if (c.isAnnotationPresent(ApplicationScoped.class)) {
                          scope = ApplicationScoped.class;
                      } else {
                          scope = NormalScope.class;
                      }
                  }
              }
          }
          return scope;
      }
  
      public synchronized void addSubResource(Destroyable object) {
          subResources.add(object);
      }
  
  }
  