content: package act.meta;
  
  /*-
   * #%L
   * ACT Framework
   * %%
   * Copyright (C) 2014 - 2018 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.app.App;
  import act.plugin.AppServicePlugin;
  import org.osgl.$;
  import org.osgl.util.Generics;
  
  import java.lang.reflect.Type;
  import java.util.HashMap;
  import java.util.List;
  import java.util.Map;
  
  public abstract class ClassMetaInfoManager<INFO extends ClassMetaInfoBase<INFO>> extends AppServicePlugin {
  
      private Class<INFO> infoType;
  
      private Map<String, INFO> map = new HashMap<>();
  
      public ClassMetaInfoManager() {
          exploreTypes();
      }
  
      public Class<INFO> infoType() {
          return infoType;
      }
  
      @Override
      protected void applyTo(App app) {
          app.register(this);
          map.clear();
      }
  
      public INFO getOrCreate(String className) {
          INFO info = map.get(className);
          if (null == info) {
              info = $.newInstance(infoType);
              map.put(className, info);
          }
          return info;
      }
  
      public INFO get(String className) {
          return map.get(className);
      }
  
      private void exploreTypes() {
          List<Type> types = Generics.typeParamImplementations(getClass(), ClassMetaInfoManager.class);
          infoType = Generics.classOf(types.get(0));
      }
  }
  