code: /*
   * Licensed to the Apache Software Foundation (ASF) under one or more
   * contributor license agreements.  See the NOTICE file distributed with
   * this work for additional information regarding copyright ownership.
   * The ASF licenses this file to You 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 org.apache.skywalking.library.elasticsearch.requests.factory.v6.codec;
  
  import com.fasterxml.jackson.core.JsonParser;
  import com.fasterxml.jackson.core.type.TypeReference;
  import com.fasterxml.jackson.databind.DeserializationContext;
  import com.fasterxml.jackson.databind.JsonDeserializer;
  import java.io.IOException;
  import java.util.Collections;
  import java.util.Map;
  import org.apache.skywalking.library.elasticsearch.response.IndexTemplate;
  import org.apache.skywalking.library.elasticsearch.response.IndexTemplates;
  
  final class V6IndexTemplatesDeserializer extends JsonDeserializer<IndexTemplates> {
      public static final TypeReference<Map<String, IndexTemplate>> TYPE_REFERENCE =
          new TypeReference<Map<String, IndexTemplate>>() {
          };
  
      @Override
      public IndexTemplates deserialize(final JsonParser p,
                                        final DeserializationContext ctxt)
          throws IOException {
          final Map<String, IndexTemplate> templates = p.getCodec().readValue(p, TYPE_REFERENCE);
          if (templates == null) {
              return new IndexTemplates(Collections.emptyMap());
          }
          return new IndexTemplates(templates);
      }
  }
  