content: /*
   * Copyright 1999-2020 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.nacos.common.remote;
  
  import com.alibaba.nacos.api.remote.Payload;
  
  import java.lang.reflect.Modifier;
  import java.util.HashMap;
  import java.util.Map;
  import java.util.ServiceLoader;
  
  /**
   * payload registry,Define basic scan behavior request and response.
   *
   * @author liuzunfei
   * @author hujun
   * @version $Id: PayloadRegistry.java, v 0.1 2020年09月01日 10:56 AM liuzunfei Exp $
   */
  
  public class PayloadRegistry {
      
      private static final Map<String, Class<?>> REGISTRY_REQUEST = new HashMap<>();
      
      static boolean initialized = false;
      
      public static void init() {
          scan();
      }
      
      private static synchronized void scan() {
          if (initialized) {
              return;
          }
          ServiceLoader<Payload> payloads = ServiceLoader.load(Payload.class);
          for (Payload payload : payloads) {
              register(payload.getClass().getSimpleName(), payload.getClass());
          }
          initialized = true;
      }
      
      static void register(String type, Class<?> clazz) {
          if (Modifier.isAbstract(clazz.getModifiers())) {
              return;
          }
          if (REGISTRY_REQUEST.containsKey(type)) {
              throw new RuntimeException(String.format("Fail to register, type: %s, clazz: %s", type, clazz.getName()));
          }
          REGISTRY_REQUEST.put(type, clazz);
      }
      
      public static Class<?> getClassByType(String type) {
          return REGISTRY_REQUEST.get(type);
      }
  }
  