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 java.util.Comparator;
  
  /**
   * Used to sort Exception based on the inheritance hierarchy
   */
  public class ExceptionComparator implements Comparator<Class<? extends Exception>> {
      @Override
      public int compare(Class<? extends Exception> o1, Class<? extends Exception> o2) {
          return hierarchicalLevel(o2) - hierarchicalLevel(o1);
      }
  
      private static int hierarchicalLevel(Class<? extends Exception> e) {
          int i = 0;
          Class<?> c = e;
          while (null != c) {
              i++;
              c = c.getSuperclass();
          }
          return i;
      }
  }
  