content: package act.inject;
  
  /*-
   * #%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 org.osgl.$;
  import org.osgl.util.E;
  import org.osgl.util.Generics;
  
  import java.lang.reflect.Type;
  import java.util.List;
  import javax.inject.Provider;
  
  /**
   * App implemented {@link javax.inject.Provider} can extends this base class to automatically register to injector
   *
   * **Note** this class will automatically register to ACT's injector. Thus if you need to configure
   */
  public abstract class ActProvider<T> implements Provider<T> {
  
      private final Class<T> targetType;
  
      public ActProvider() {
          targetType = exploreTypeInfo();
      }
  
      protected ActProvider(Class<T> targetType) {
          this.targetType = $.requireNotNull(targetType);
      }
  
      public Class<T> targetType() {
          return targetType;
      }
  
      private Class<T> exploreTypeInfo() {
          List<Type> types = Generics.typeParamImplementations(getClass(), ActProvider.class);
          int sz = types.size();
          E.illegalStateIf(1 != sz, "generic type number not match");
          Type type = types.get(0);
          E.illegalArgumentIf(!(type instanceof Class), "generic type is not a class: %s", type);
          return (Class) type;
      }
  
  }
  
  
  