content: /*
   * Copyright 1999-2019 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.demo.commandhandler;
  
  import com.alibaba.csp.sentinel.command.CommandHandler;
  import com.alibaba.csp.sentinel.command.CommandRequest;
  import com.alibaba.csp.sentinel.command.CommandResponse;
  import com.alibaba.csp.sentinel.command.annotation.CommandMapping;
  
  /**
   * This class is a demo shows how to create and register a customized CommandHandler.
   *
   * <ul>
   * <li>1. Create a class which implements the {@link CommandHandler} SPI interface</li>
   * <li>2. Use a {@link CommandMapping} to specify the url and desc of your CommandHandler</li>
   * <li>3. Implement your own {@code handle} method </li>
   * <li>4. Add your CommandHandler in {@code com.alibaba.csp.sentinel.command.CommandHandler} file which is stored in
   * {@code resources/META-INF/services/} directory </li>
   * </ul>
   *
   * @author houyi
   */
  @CommandMapping(name = "echo", desc = "echo command for demo")
  public class EchoCommandHandler implements CommandHandler<String> {
  
      @Override
      public CommandResponse<String> handle(CommandRequest request) {
          String name = request.getParam("name");
          if (name == null || name.trim().length() == 0) {
              return CommandResponse.ofSuccess("Tell us what's your name by submit a name parameter");
          }
          return CommandResponse.ofSuccess("Hello: " + name);
      }
  
  }
  