content: /*
   * Copyright (C) 2020 ActiveJ LLC.
   *
   * 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 io.activej.inject;
  
  import org.jetbrains.annotations.Nullable;
  
  import java.util.function.Supplier;
  
  public interface ResourceLocator {
  	<T> T getInstance(Key<T> key);
  
  	default <T> T getInstance(Class<T> type) {
  		return getInstance(Key.of(type));
  	}
  
  	<T> @Nullable T getInstanceOrNull(Key<T> key);
  
  	default <T> @Nullable T getInstanceOrNull(Class<T> type) {
  		return getInstanceOrNull(Key.of(type));
  	}
  
  	default <T> T getInstanceOr(Key<T> key, T defaultValue) {
  		T instance = getInstanceOrNull(key);
  		return instance != null ? instance : defaultValue;
  	}
  
  	default <T> T getInstanceOr(Class<T> type, T defaultValue) {
  		return getInstanceOr(Key.of(type), defaultValue);
  	}
  
  	default <T> T getInstanceOrCreate(Key<T> key, Supplier<T> defaultValueFn) {
  		T result = getInstanceOrNull(key);
  		if (result != null) return result;
  		return defaultValueFn.get();
  	}
  
  	default <T> T getInstanceOrCreate(Class<T> type, Supplier<T> defaultValueFn) {
  		return getInstanceOrCreate(Key.of(type), defaultValueFn);
  	}
  }
  