content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * 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 com.alibaba.csp.sentinel.command;
  
  /**
   * Command response representation of command center.
   *
   * @param <R> type of the result
   * @author Eric Zhao
   */
  public class CommandResponse<R> {
  
      private final boolean success;
      private final R result;
      private final Throwable exception;
  
      private CommandResponse(R result) {
          this(result, true, null);
      }
  
      private CommandResponse(R result, boolean success, Throwable exception) {
          this.success = success;
          this.result = result;
          this.exception = exception;
      }
  
      /**
       * Construct a successful response with given object.
       *
       * @param result result object
       * @param <T>    type of the result
       * @return constructed server response
       */
      public static <T> CommandResponse<T> ofSuccess(T result) {
          return new CommandResponse<T>(result);
      }
  
      /**
       * Construct a failed response with given exception.
       *
       * @param ex cause of the failure
       * @return constructed server response
       */
      public static <T> CommandResponse<T> ofFailure(Throwable ex) {
          return new CommandResponse<T>(null, false, ex);
      }
  
      /**
       * Construct a failed response with given exception.
       *
       * @param ex     cause of the failure
       * @param result additional message of the failure
       * @return constructed server response
       */
      public static <T> CommandResponse<T> ofFailure(Throwable ex, T result) {
          return new CommandResponse<T>(result, false, ex);
      }
  
      public boolean isSuccess() {
          return success;
      }
  
      public R getResult() {
          return result;
      }
  
      public Throwable getException() {
          return exception;
      }
  }
  